by piero scaruffi

Researchers are welcome to submit news and articles about breakthroughs and events in the areas of cognitive science, artificial intelligence, neurobiology, artificial life, linguistics, neural networks, connectionism, cognitive psychology, mind, philosophy, psychology, consciousness. Email the editor at this Email address. Readers who would like to receive periodic news and updates on cognitive science, philosophy of mind, neurobiology, artificial intelligence, etc, are invited to register to my mailing list. My book on consciousness | My reviews of books My seminar on Mind/Consciousness | My seminar on History of Knowledge September 2007 August 2007 The Swedish neuroscientist Henrik Ehrsson of the Karolinska Institute in Stockholm (Sweden) has induced "out-of-body experiences" (experiences in which a person looks at himself/herself from outside her/his body) in a laboratory by having the person wear virtual-reality goggles and look at herself/himself from behind. A similar experiment was successfully performed by the Swiss neuroscientist Olaf Blanke of Geneva University (Switzerland). In the past he had learned that he could induce out-of-body experiences at will in some epileptic patients by electrically overstimulating a particular part of the brain (the right angular gyrus, that plays a role in integrating sensory inputs). An epileptic fit is basically an electrical overstimulation, which explains why epileptic patiens often report out-of-body experiences. The USA neurologist Bradley Schlaggar at Washington University in St Louis has shown why the adult brain "thinks" differently about long-term goals than a child's brain. The key factor is the way the cingulo-opercular network and the frontoparietal network are integrated. In children the two networks are basically one single network. In teenagers they are partially divided. In adults they are two distinct networks. The human brain grows rapidly in the first six years of life, but then hardly grows at all anymore. What changes is the way its regions are connected, or, better, how they get disconnected. July 2007 The Austrian biochemist Martin Nowak at Harvard University claims that cooperation is on the same level as mutation and selection as one of the factors that determine evolution. Mutation and selection alone would be enough to explain how species evolve, but they would not be enough to explain how new levels of biological organization evolve (for example, how multicellular organisms arose from single-celled organisms). Nowak has employed game theory to show mathematically how clusters of cooperators emerge spontaneously in a network of organisms. The British neuropsychologist Chris Frith at University College London has worked out a model of how "unconscious" and "conscious" decisions are made. According to this bottom-up model, an evolutionarily older part of the brain is the first one to make a decision on how to act, and only later interacts with the higher-level evolutionarily-younger conscious regions. June 2007 The recently published Encyclopaedia of DNA Elements (ENCODE) at the Sanger Institute of Cambridge (Britain) shows that protein-coding genes might be in the minority. More and more kinds of RNA are being discovered. Genes are not mere repositories of information about how to build proteins: they are also (and maybe mainly) RNA factories. In turn, some kinds of RNA regulate the life of many protein-encoding genes. DNA contains the instructions (the genes) for making proteins. RNA is the chemical that carries genetic information from the DNA in the nucleus to the location in the cell where proteins are made so that the appropriate amino-acid units can be put together to assemble the proteins. The number of protein-coding genes seems to be mostly the same for all animals, from flies to humans (in the range of 20-30,000). However, the number of genes whose RNA performs other functions vary wildly among species. RNA acts as a simple "messenger" only in simpler organisms. RNA acts more like a manager in complex organisms, i.e. its "regulating" activities are much more widespread. May 2007 The German molecular biologist Detlev Arendt of the European Molecular Biology Laboratory in Heidelberg claims that an ancient organism already exhibited the central nervous system of modern animals. The Urbilateria, a tiny worm-like organism that lived one billion years ago, is the ancestor of insects, molluscs, worms and vertebrates (birds, fish, mammals, reptiles, amphibians). What all these animals have in common is that their body is mostly symmetrical across an axis running from head to feet. Coincidence or not, it turns out that this is also the oldest known organism to boast a central nervous system. The USA psychologist Amy Pollick at Emory University in Atlanta, has developed a theory that some of the great apes have both a repertory of facial/vocal expressions (that are innate, i.e. genetic) and a repertory of body gestures, that are learned. The meanings of the former repertory is the same regardless of geography. The meanings of latter depend on the context. In the beginning, language may have been movement, not sound. Biologists of the ANDEEP (Antarctic benthic deep-sea biodiversity) project have discovered more than 700 new species of marine creatures in seas surrounding Antarctica. DNA alasyses seem to prove that the world's deep sea areas were colonised by creatures from the Antarctic. Angelika Brandt said: "The Antarctic deep sea is potentially the cradle of life of the global marine species". March 2007 The USA neurobiologist Frank Werblin and the Swiss neurobiologist Botond Roska have discovered that the retina is basically an appendix to the brain. It contains the same kind of cells that the brain is made of (neurons) and these cells process the visual input way before it reaches the brain proper. The brain proper basically receives not a sensory input from the retina but a flow of pre-processed information January 2007 The USA biologist David Haussler has found evidence of the genetic information (the piece of DNA) that makes the human brain so different from the brains of other animals. This "information" is actually not genes, but "programs" that determine which genes are expressed. Haussler calls these programs "Human Accelerated Regions" or "HARs". See their article. December 2006 The Israeli physician Moshe Szyf has found evidence that experience affects the way genes are expressed. Every cell in the body contains the same genetic information (the same genes), but the same genetic information is expressed in different ways in different cells (so that, for example, some cells become skin cells and some cells become eye cells). The program that controls the expression of the genome is the epigenome. Its functioning is still largely unknown. Szyf has found that early experience of the child affects the future psychological life of the child not only because it is stored in memory but also because it determines how some genes will be expressed. Szyf has observed physical differences in the hippocampus of rats that account for differences in behavior, and he argues that those differences were caused by the way their mothers raised them. Rats who were raised in similar ways by their mothers tend to have the same kind of hippocampus. He credits this development to the expression of some genes as opposed to others. Maternal care seems to affect the chemistry within the cell that determines if and when those genes are expressed. The effects are visible during the first week of life after birth. November 2006 Mayank Mehta at Brown University has discovered that the neocortex controls the creation of long-term memories. Memories are consolidated every night. As we sleep, our brain transfers memories of the day's events from the hippocampus, which is part of the evolutionarily older part of the brain (and shared with many other species), to the neocortex, which is the newer part of the brain and is almost exclusive to humans. This unconscious process creates long-term memory. It now appears that this process is controlled by the neocortex, because the neurons of the two regions are synchronized in an asymmetric way: a rhythmic pattern of the excitatory cells in the neocortex corresponds to a rhythmic pattern of the inhibitory neurons in the hippocampus. Therefore the neocortex appears to be dominant. In general, this is another example of how different regions of the brain communicate: by synchronized firing of neurons (as opposed to a linear transmission of information from neuron to neuron to neuron). Eleanor Maguire at the University College London has discovered how the hippocampus generates a sequence of neural events in response to a single perception. A possible interpretation of this sequence of events is that the hippocampus automatically generates a "script" of what it expects to perceive next. If the sequence of events is not realized, the hippocampus generates a pattern of activity in the rest of the brain. If the sequence of events is realized, the hippocampus continues its normal routine. This seems to indicate that the reasoning of the hippocampus is expectation-driven. The hippocampus compares what it knows with what is happening. If nothing new is revealed, the hippocampus continues its normal chores. If the two do not match, then it means that this is a new, unknown situation and the hippocampus has to alert the rest of the brain that some additional processing is required. October 2006 Michael Ullman of Georgetown University Medical Center has discovered that girls and boys learn language in very different ways. They tend to use different parts of the brain. While they both, at the end, learn to speak the same language, the process by which they learn is significantly different. Girls tend to learn by memorizing words and their relationships. Boys tend to learn the rules of language. These skills belong to different areas of the brain. This finding has at least two consequences. First of all, it proves one more time that the brains of males and females are different and work in different ways, a fact that is often downplayed in the name of political correctedness. Second, it proves that there can be multiple ways to achieve "intelligence" (at least two, but possibly even more). Both ideas can apply to any cognitive task. September 2006 The Italian neurologist Giacomo Rizzolatti discovered ("Action Recognition in the Premotor Cortex", 1996) that the brain of primates uses "mirror" neurons to represent what others are doing. De facto, my brain contains a representation of what someone else is doing, and that representation helps me "understand" what the other person is doing, for example her intention and her emotions. We effortlessly understand the intention and emotion of others not because we carry out complex reasoning procedures about their actions but because their intentions and emotions are physically reproduced inside our own brain. In fact, a brain only needs to see the beginning of an action by another person in order to guess the intention of it: based on the context, the mirror neurons instantly reproduce the brain state of the other person and therefore help to understand what the other person is trying to do and what will happen next. These mirror neurons are widespread in the cortex of primates (not only of humans). These mirror neurons fire both when the action is performed and when the action is observed in other individuals. The Indian neurologist Vilayanur Ramachandran ("Mirror Neurons and Imitation Learning", 2000) subsequently speculated that mirror neurons may be crucial in learning and understanding language. August 2006 It has always been a tenet of neuroscience that the neural organization of the brain must change in response to experience. The theory has finally been confirmed visually by Kuan Hong Wang and Susumu Tonegawa at MIT's Picower Institute for Learning and Memory: for the first time scientists have been able to watch neurons (at a single-cell resolution) within the brain of a living being as they change in response to experience. They were able to do so for a prolonged period of time, focusing on the role of the protein called "Arc", which is believed to consolidate long-term memories by strengthening synapses. They now speculate that the same protein may help train the brain to recognize images (the more an animal is exposed to shapes, borders and shades of light, the better it gets at recognizing them). Synapses are continuously modified to reflect the brain's experience ("learning"). Such Changes in synaptic strength require rapid protein synthesis, whose chemistry is not well known because it has never been closely monitored. Marcus Kaiser at Newcastle University in Britain has found out that long nerve fibres represent a crucial part of the nervous system. The traditional model of the brain implies that messages are sent through the brain via many connections to many neurons, but Kaiser claims that long connections can substantially reduce the "journey" of a message and, at the same time, increase its accuracy (just like an express non-stop train increases the speed and the reliability of a journey compared with the same journey done in stages on local trains). Henry Markram and Jean-Vincent Le Be' at the Ecole Polytechnique Federale of Lausanne (Switzerland) have verified that the connections between neurons are routinely changed within a few hours. The plasticity of the brain exceeds even the most optimistic predictions. July 2006 The British neurologist Simon Baron-Cohen of Cambridge University is studying the difference between male and female brains. Men and women are programmed by their genes to behave in different ways, and that difference shows up in the organization of the brain. But the "standard" brain is not the male one, it is the female one: until the second month of gestation the brain of every foetus is "female". It is only later (and particularly after birth) that the male brain begins to dramatically diverge from the female one. Within a year of birth boys and girls already demonstrate wildly different preferences for toys. The brains of adult men end up being about 9% larger than those of adult women, although the number of neurons seems to be identical (i.e., female brains are more "dense"). The main organizational difference that has emerged so far is that men can use only one hemisphere to solve some problems whereas women always employ both hemispheres. Female brains seem programmed to understand emotions (empathising) whereas male brains seem programmed to build systems (systemising). Andrea Berger and Gabriel Tzur at Ben-Gurion University of the Negev in Israel used brain-monitoring technology developed at the National Institute on Deafness and Other Communication Disorders are studying the emergence of language areas in non-human primates. The areas of the human brain that are involved in language processing are mainly Broca's area and Wernicke's area, that work in tandem. Measuring neural activity in the brain areas of monkees that are their equivalent of Broca's area and Wenicke's area, the researchers have been able to figure out that monkees exhibit the same pre-linguistic activity, even though they do not express it linguistically. The theory now is that there exists a larger area of the primate brain that is in charge of social interaction, and that human language is merely a human specialization of a region of that area. June 2006 James Roney of the University of California at Santa Barbara has proven that women can tell if a man is fond of children just by looking at him. Daniel Hulme at the London's Global University provides a good overview of the state of the art in Artificial Life. Shahar Arzy of the Ecole Polytechnique Federale of Lausanne (Switzerland) studies how we feel that we live inside our body. This feeling is created by the interaction between two brain areas: the temporoparietal junction (TPJ), that creates the concept of the self, and the extrastriate body area (EBA), that recognizes human bodies and body parts. May 2006 Japanese neuroscientist Yukiyasu Kamitani of the Advanced Telecommunications Research Institute (ATR) has developed a technique to "decode the perceptual and subjective contents of the human brain" to guide a robot. This technique has allowed ATR to build a "Brain Machine Interface" that allows a robot to obey the commands of a human brain. The computer decodes the brain activity, understands the movement that the brain wants to obtain, and directs the robot to perform that movement. Bryan Raudenbush claims that chocolate boosts cognitive activities. Tests seem to prove that cognitive performance including memory, attention span, reaction time, and problem solving increases after eating chocolate (that is known to contain stimulants such as theobromine, phenethylamine, and caffeine). April 2006 Japanese scientist Hiroshi Ishiguro is developing anthropomorphic robots modeled on real people. His robots look like clones of real people: not only their faces and their bodies have been replicated, but the robot even tries to copy the movements of the real person. It will eventually be possible for a human being to observe its robotic clone, i.e. for you to see yourself as the others see you. "Repliee Q2" is the latest release. British psychologists Klaus Zuberbuhler and Kate Arnold are studying the language of some African monkees that apparently are able to combine sounds to produce different meanings, a key feature of human language. March 2006 American neurologist Andreas Meyer-Lindenberg of the National Institute of Mental Health has presented a theory to explain why some individuals are more likely than others to develop a violent personality. There are different versions of the gene "monoamine oxidase", responsible for making the enzyme that breaks down serotonin, which in turn is one of the neurotransmitters that carries signals from neuron to neuron. One particular version is less effective than the others and therefore causes more serotonin to accumulate in the brain as it develops. These brains (and therefore these individuals) seem to be less capable of inhibiting impulsive reactions. In other words, this particular version of the gene seems to lead to the development of a brain that is somehow deficient in the part that handles emotions. Experiments with neural-controlled devices have been performed for several years, but the Fraunhofer Institute in Berlin has demonstrated one that seems to be more than a novelty. The Berlin Brain-Computer Interface (BBCI) allows a user to mentally control the movement of a cursor on the screen of a computer. Instead of the mouse, the user is equipped with an electronic hat that picks up electrical activity inside the brain (the same principle of the electroencephalogram). The user moves the cursor by focusing on the desired movement. The device is smart enough to learn what commands correspond to the neural patterns. February 2006 Leonard Susskind's book "The Cosmic Landscape" has made popular the term "landscape" to mean the multiple universes, each with its own different physical laws, that are compatible with string theory. String theory basically amplified the uncertainty of Quantum Mechanics. String Theory does not prescribe exactly how the universe should be, but leaves plenty of room for different kinds of universes to exist. Susskind is one of the physicists who take it seriously and believe that there "are" indeed multiple universes. Now an increasing number of physicists side with him (see this overview), despite the fact that other physicists think this is not science but religion (see this blog). January 2006 Researchers at the Center for Behavioral Neuroscience of Emory University (USA) have been studying the molecular (if not genetic) bases for complex behavior (Click here for their original paper). They noticed that prairie voles (Microtus ochrogaster) tend to be monogamous and build societies, whereas the closely related meadow voles (Microtus pennsylvanicus) tend to be polygamous and live alone. Scott Edwards and David Self of the University of Texas Southwestern Medical Center (USA). It turns out that the chemical processes in the brains of these two species exhibit a key difference: dopamine fosters bond formation in prairie voles. (Dopamine is the same chemical responsible for drug addiction). It also turns out that this chemical idiosyncrasy is due to the expression of a single gene. Thus indirectly this study has proven that a single gene can have a profound influence on complex social behaviour. (Monogamy is rare among mammalian species). December 2005 In what could be one of the most important events of the new century, the Blue Brain Project was launched by Lausanne's Brain Mind Institute (Switzerland) and IBM in may 2005, under the direction of Henry Markram, with the objective to create software replicas of the neocortical column and, ultimately, the whole brain. These replicas could then be used for real-time simulations, shedding light on both neural diseases and "normal" mental life. The neocortical column is particularly interesting because it is relatively small among the brain regions that act as a functional whole. It also represents a key difference between reptilian and mammalian brains. Its size is minuscule (about 0.5mm wide and 2-4mm high) but, needless to say, immensely complex. It will take the power of the eighth most powerful computer in the world to build the model. November 2005 Scientific American of December 2005 has an article on Kim Peek, a "savant" in the age of cognitive science. Reports of savants in history abound, but for the first time a savant is alive in an age in which scientists know enough of the brain's structure to try to explain where those skills come from. Peek, among many other marvels, has memorized 9,000 books: he is becoming a living library. Like all savants that we have knowledge of, he is severely limited in his cognitive abilities (for example, he needs help to get dressed). Neuroscientists have already determined that his brain lacks a corpus callosum, and pretty much any other structure that connects the two hemispheres. We know that "brain damage" has the side effect of enhancing some cognitive abilities (e.g., blind people hear "better" than non-blind people), but one has to wonder which is the damaged brain: Peek's brain can do things that "normal" humans cannot do. Could it be that at some point in evolution all humans had his skills, and later most humans lost those skills because their brain got damaged or because their brain evolved in a way that limited the original functions? October 2005 Rodrigo Quian Quiroga is investigating a new theory about how the brain recognizes faces. Traditionally, it has been thought that large sections of the brain work together to create some kind of map of the face. Quiroga is testing a theory that there is a single neuron in the brain for recognizing each face. If this theory is right, some neurons should fire only when a certain face is recognized. Preliminary tests seem to prove that this is indeed the case. September 2005 Experiments by Gunter Loffler, Frances Wilkinson and others on how the brain representats faces seem to prove that the brain recognizes a specific person's face based on geometric "distance" from the prototypical face. Functional magnetic resonance imaging identify a region of the cortez, the "fusiform face area", that is specialized for face processing. Basically, this region "knows" what a face is (eyes, mouth, nose, etc and their spatial relationship) and determines how close your face is to that prototype. Norwegian scientist Torkel Hafting Fyhn and others have shown that the complex task of navigating the environment is managed by the brain mainly in the entorhinal cortex. This region seem to contain information about the geometry of the environment, because neurons are triggered in a coordinated pattern when the individual's position coincides with the vertices of a grid of triangles. August 2005 Observations have shown that breeding offspring is a costly job that usually takes a toll on the mother's longevity. Swedish evolutionary biologists (including Alexei Maklakov) has found that there is at least one notable exception: somehow late sex helps some female insects (Acanthoscelides obtectus) live longer. It looks like something in the semen of the males helps women live longer if they have to bear offspring later in life. A male's semen is a complex of proteins and peptides, which is now being studied to see what effect it may have on the biological clock of a female (not only on her reproductive organs). USA scientists at several universities have mapped the genome of the chimpanzee (3 billion bits of genetic code). The chimpanzee is humankind's closest relative. As expected, the genome of the chimpanzee is almost 99% identical to the human genome. The chimpanzee and the first hominid arose from a common ancestor about 6 million years ago. There took place 40 million molecular changes that ended up differentiating humans from chimpanzees, although probably only a fraction of these are responsible for the most visible differences between the two species. July 2005 Tony Plant at Pittsburgh's Univeristy and Mark Carlton at Cambridge University are investigating how puberty is regulated by a biological clock in the hypothalamus. At some point, the KiSS-1 gene sends out a signal that triggers another gene, GPR54, which triggers a brain hormone, the gonadotropin-releasing hormone (GnRH), which causes the secretion of pituitary hormones, which stimulate ovarian and testicular functions. All of this apparatus is already present in the child (actually, even in the foetus), but it is set in motion only when the biological clock "wakes up" the KISS-1 gene. Margaret Titus has shown that myosins (a family of protein motors, that take care of chores such as organelle transport, cellular migration, etc) can shed light on the evolution of multi-cellular organisms, as myosins seem to have diversified during eukaryotic evolution by the addition or subtraction of protein domains. June 2005 It had been known for a while that male damselflies have a homosexual tendency not quite common among other species. This is commonly explained as due to the fact that the females frequently behave like males, as if testing how smart the males are in recognizing the real females (see for example this article). Now entomologist have discovered an all-female population of damselflies in the Azores archipelago of Portugal, which adds to the discovery of all-female populations of Fijian damselflies, for which males have never been discovered (see for example this article). If either is confirmed, this would be another case of parthenogenesis (reproduction without any need for fertilization), which is known to occur among insects such as aphids and ants (but the unfertilized egg of an ant yield males only). Species that are capable of parthenogenesis are also the only species capable of self-cloning (the children are sometimes genetically identical to the mother). May 2005 Debra Niehoff's "The Language of Life: How Cells Communicate in Health and Disease" is an excellent book to get an introductory description of how cells communicate. More importantly, it draws an important parallel with "language". Two cells that exchange chemicals are doing just that: "talking" to each other, using chemicals instead of words. Those chemicals are bound in molecular structures just like the words of human language are bound in grammatical structures. Even before social behavior was invented, there was a fundamental language of life. Living cells communicate all the time, even in the most primitive organisms: cell communication is the very essence of being alive. The "higher" forms of communication that do not involve chemical exchange still cause some chemical reaction. A bee that "dances" in front of other bees or a human brain that learns something from another human brain have undergone chemical change, that has triggered changes in their cognitive state. From this point of view, there are at least three main levels of communication: a cellular level, in which living cells transmit information via chemical agents, a bodily level, in which living beings transmit information via "gestures", and a verbal level, in which living beings transmit information via words. Each level might simply be an evolution of the previous one. April 2005 Peter Tyack of the Woods Hole Oceanographic Institution, Angela Stoeger-Horwath of the University of Vienna (Austria) and others have discovered that elephants are capable of imitating the vocals of other elephants. This follows similar discoveries about dolphins, most birds, primates, and even bats, and thus leads to suspect that vocal imitation plays a larger role in life. These scientists speculate that vocal imitation might be a way to identify members of the same group, in the same way that a dialect identifies humans of the same group (the moment you open your mouth, people know which region you are from). TRP (Transient Receptor Potential) channels are used by the sensory systems to detect heat, cold, taste, pain and so forth. (See for example this article). New studies reveal that they also determine how axons of nerve cells grow. Johan Holmberg of the Nobel Institute in Sweden (See the paper) has discovered that ephrins (already known to be important regulators of cell migration and synapse formation) are also controlling the proliferation of neurons in the adult brain. Removing ephrin, increases the number of neurons that are created. This discovery could lead to artificial means to stimulate neural growth in the adult brain. Jeff Hawkins of the Redwood Neuroscience Institute, who in 1992 co-founded Palm Computing, has started a software company, Numenta, based on the theories of his book "On Intelligence: How a New Understanding of the Brain Will Lead to the Creation of Truly Intelligent Machines". March 2005 Time Magazine of March 7 has an article on whether the female brain is "inferior" to the male brain as far as the sciences go. The debate was started many years ago when it was confirmed that the male brain is about 10% larger than the female brain. Later studies revealed that the female brain "matures" faster than the male brain. More studies showed that some parts of the brain mature faster in boys. So the verdict is still out, and might well be the other way around. The article correctly points to the fact that the USA is one of the few western countries in which any gap is discernible between male and female success in math: in most European countries (including the University where I graduated) women tend to perform slightly better in math than men. The size of the brain is probably far less important than social factors in shaping who does what better. See also this page by the Dana Alliance for Brain Initiatives. About the brain growth, see this interview with Jay Giedd. February 2005 Tatsuya Hirano of the Cold Spring Harbor Laboratory has published results of his studies on what process helps repair damaged DNA: its complementary copy serves as a template. Michael Hengartner at the Institute of Molecular Biology (Switzerland) has discovered that the nematode worm, often studied for blues on programmed cell death (the process that, ultimately, kills us), exhibits a fragmentation of mitochondria that is similar to the death process in mammals. January 2005 Cholinergic neurotransmitters represent one of the fundamental chemical "systems" of the brain. By studying the transport of choline to the neurons (through what is called "the high-affinity choline uptake transporter" or CHT) Martin Sarter at the University of Michigan cholinergic activity in the cortex and hippocampus is crucial for conscious processes. (Abstract). December 2004 Investigating how children can possibly learn language at such remarkable speeds, Patricia Kuhl at the Institute for Learning and Brain Sciences at the University of Washington has discovered that the human brain in its early stages is particularly interested in classifyin the statistical and prosodic patterns in language. The statistical distributions of sounds is used to infer phonemes and words. This process of language learning has a significant impact on the brain, because it alters the very way the brain works (basically, the brain tunes itself to detecting those patterns of speech). Thus the first language is learned faster than any other language, because other languages use different patterns from the ones that the brain has been modeled in early years to detect. November 2004 Stephen Maren at the University of Michigan has showed that the amygdala is crucial for remembering experiences that were associated with fear, and how the amygdala and its interaction with the hippocampus and prefrontal cortex, contribute to this process. William Schwartz of the University of Massachusetts Medical School has identified the neural circuits in the brain of fruitflies that are sensitive to sunrise and sunset and used them to set the circadian clock (the day-night cycle). October 2004 Anthropologists led by Peter Brown of University New England in Australia have found the bones of a dwarf human-like species that probably lived isolated on the remote Indonesian island of Flores until 12,000 years ago. They were about one meter tall, and their head was about 15 cms wide. It rests to be seen if this is indeed a human (homo) species or a contemporary species of apes. It could be that "Homo Erectus" (which started spreading around the world about one million years ago) landed on Flores and then remained "locked" in the island. As time went by, the species got smaller. (An isolated mammal gets smaller over time: evolution favors the survival of smaller individuals). Homo Sapiens (us) arrived in Flores sometime between 50,000 and 10,000 years ago, and it may have coexisted with this dwarf species for a while. This is, in other words, another case of coexisting "homo" species, like the Neanderthals in Europe (which disappeared around 28 000 years ago). The Human Genetics group at the Sanger Institute in Cambridge has revised the number of genes in the human genome down to 20,000 DNA mostly consists of genes encoding proteins, and regulated by proteins. But a parallel regulatory system seems to exist that is based on RNA: "introns" do not code for proteins (and have long been considered evolutionary leftovers with no usual function) but may be coding for RNA that has a regulatory function. This additional regulatory system (interacting with the protein-based regulatory system) would help explain the complexity of organisms that is still largely unexplained. The Cambrian explosion that witnessed the creation of thousands of complex organisms may be due to the birth of this parallel regulatory system. In a widely-publicized new book, Dean Hamer of the National Cancer Institute speculates that human belief in Gods is genetic: a gene. The book is getting a lot of press, but few reviewers mention that Hamer is the same biologist who once (in 1993) claimed that the X chromosome causes homosexuality, a claim that has been widely discredited. The evidence he provides for his new thesis is very weak. At best, it is an intriguing idea, although an old one: philosophers and anthropologists have long believed that humans are born with a predisposition to "religion". September 2004 Dirk Cysarz of Herdecke University is studying the relationship between breathing, heartbeat and rhymed poetry. Among the many biological clocks that control the human body, there are two that are vital: the Mayer waves (ten-second cycles of blood pressure fluctuation) and the breathing cycle (15 breaths per minute). These two vital clocks are not in sync, although one needs the other. Hexameter is the most classic of classic poetry, used by Homer as well as in other civilizations. Cysarz found that reciting hexameter poetry has the effect of synchronizing breathing and heart rate. Similar phenomena are known to occur during the recitation of the Catholic rosary and the "om" mantra. The cardiorespiratory synchronization is probably due to the specific breathing patterns required to recite the verse. So it might be that classic poetry was born because it "felt good" to recite it, and only later was also used to deliver a message. Claudio Bassetti at the University Hospital of Zurich has been able to locate an area of the brain that is definitely affected by dreams. He analyzed the brain patterns of a woman who lost the ability to dream (Charcot-Wilbrand syndrome) after she had a stroke and deduced that the damaged area was an area that is involved in vision, emotion and memory The woman continues to have REM sleep as normal, which confirms recent findings that dreaming and REM sleep occur in different brain systems. August 2004 Nipam Patel at the University of Chicago, who has been studying the relationship between genes and development (how the body ends up having the shape it has), The Hox Complex is a cluster of genes that controls development, that is shared by many species and that probably existed in the ancestor to all vertebrates. The way the HOx genes express themselves is extremely important, as proven by the fact that altering the regulation of just one Hox gene (Ubx) transforms a normally two-winged fly into a four-winged mutant. Patel has now proven that there is a reason of the Hox complex is the same in all species that have it: the genes must be expressed in a temporal order in order to make sense in space. Peter Gordon of the Columbia University has tested Whorf's theory (that the language we speak determines the way we think) on a South American tribe that has never invented numbers. Gordon found out that members of this tribe are indeed unable to "count". July 2004 Ellen Bialystok, a psychologist at York University (Canada) has conducted studies on bilingual people, and concluded that practicing two or more languages may help slow mental decline. She also conducted a study that showed bilingual students scored several points higher than their monolingual peers, and a study on child language acquisition that showed that bilingual children learn to read sooner and are are better at problem solving. American anthropologist Rachel Caspari of the University of Michigan and Sang-Hee Lee of the University of California at Riverside have presented a theory that humans had a fundamental evolutionary advantage over other species. Caspari and Lee calculated the proportion of older to young adults in the human fossil record, and realized that it increased dramatically in the upper Paleolithic. Apparently, around 30,000 years ago humans started living longer and longer lives. That caused a population explosion, as humans kept having children even after their children had children, and older humans helped protect younger ones. June 2004 German researchers Asif Ghazanfar and Laurie Santos at the Max Planck Institute for Biological Cybernetics have investigated how the human brain came to be specialized to social interactions. They believe that social interaction requires special brain structures. A social animal needs to be able to think like its peers in order to compete with them, predict their moves, plan its own moves. The brain of a social animal must be able to interpret some sensory input as relevant to socialization. They introduce the concept of a "Machiavellian Agent" that carries out that function. May 2004 A new website on Neurogenomics, a discipline at the intersection of Neurobiology and Genetics. Neurogenomics is the study of how the genome contributes to the growth and structure of the nervous system. You can also view the Neurogenomics Project at Northwestern University Paul Chadderton and colleagues at UCL's Wolfson Institute for Biomedical Research is studying the kind of computations performed by the input layers of the brain cortex (input representation) and granule cells in the cerebellum (memory storage). See their paper. How cooperation (pervasive in the animal world) emerged through the process of natural selection (which is essentially a competitive, not cooperative, process) has been a puzzle since Darwin. Martin Nowak and his colleagues at the Harvard Program for Evolutionary Dynamics have developed a mathematical model (based, unlike traditional models, on finite populations) that shows which conditions would favor the "victory" of cooperators over competitors. See their paper. Archeologist have found evidence of fire as far back as 750,000 years ago. See this article. Horacio de la Iglesia of the University of Washington and colleagues have shown that the brain contains several clocks (not just one) that might go out of step (for example, during "jet lag"). See the press releases. April 2004 A new website on Neurogenomics, a discipline at the intersection of Neurobiology and Genetics. Neurogenomics is the study of how the genome contributes to the growth and structure of the nervous system. You can also view the Neurogenomics Project at Northwestern University March 2004 New Zealand's biologist Russell Gray has used biological methods to assess the relationship among the various languages of the Earth, and has drawn a comprehensive family tree (Gray's paper on the tree of languages). While the tree is fundamentally the same that linguists had already mapped, Gray's innovation rests in the dates: he credits just about every language with a birth date which is much earlier than held by linguists. In particular, Gray's dating has an impact on the Indo-European debate: Dr. Gray's calculations date the earliest Indo-European language as 8,700 years old. Marija Gimbutas pioneered the thesis that the Indo-Europeans migrated from the Urals towards both Europe and Persia-India in 4,000 BC, whereas Colin Renfrew claimed that the Indo-European language migrated from Turkey towards Europe and Persia with the spread of agriculture in 7,000 BC. Gray's work seems favors the latter thesis. February 2004 "Prions" are proteins that can reproduce. Eric Kandel at Columbia University has discovered that electrical signals flip some proteins of the synapsis into prions, and that such prions replicate, and that the prions strengthen connections with neighboring neurons. In other words, the transformation of these proteins into prions creates a permanent memory trace of the event that generated the electrical signal. Simone Reinders of Groningen University Hospital (Netherlands) has been able to "photograph" the different neural activity of the two personalities that coexist in the brain of patients with "multiple personality disorder". The neural activity of each personality is significantly different depending which personality is in control. John Disterhoft of the Feinberg School of Medicine at Northwestern University in Chicago believes that the cause of Alzheimer's disease is a protein called "amyloid beta". December 2003 The invention of art had already been dated at about 30,000 years ago after the discovery of the statue of a woman in Willendorf, Austria. Now Nicholas Conard of the University of Tuebingen (Germany) has discovered a set of 2cm-tall figurines (a horse head, a water bird and a cat-like animal) in a cave in southwestern Germany. Besides shedding light on the development of artistic skills, this discovery also seems to confirm the theory that Europe was settled by people who migrated along the river Danube. The sophistication of the figurines shows that those immigrants were skilled in tool making and using. The rise of art is important for the study of cognition because it implies the ability to communicate by symbols. By the same token, those people were probably speaking a complex language as well. November 2003 Theories of consciousness based on Quantum Mechanics often use Bose-Einstein condensates (the most highly ordered structures in nature) as their building blocks (see this chapter of my book). The intriguing feature of a Bose-Einstein condensate is that the many parts of a system not only behave as a whole, they become whole. Their identities merge in such a way that they lose their individuality. If Bose-Einstein condensation occurs at body temperatures in brain cells (as predicted by Herbert Froehlich), then they could account for the most popular features of consciousness. In 1999, Debbie Jin of the University of Colorado (Boulder, USA) discovered a substance obtained by cooling a vapor of fermions (the basic building blocks of matter) to almost absolute zero: the "degenerate Fermi atomic gas". Now, researchers of Debbie Jin's group have synthesized a molecular Bose-Einstein condensate from such a degenerate Fermi gas. (This condensate is a step towards achieving superfluidity in a dilute gas of fermionic atoms, the equivalent of superconductivity in metals). Cyrille de Joussineau at the University of Montpellier II (France) has observer cells that communicate their instructions to neighboring cells by growing "fingers" (filopodia) and thus "touch them". This fact is relevant for studies on "signaling": how cells signal to other cells. For example, during development (of an organ, of a limb, of a neural area) cells must signal to each other: they must coordinate what that particular region of the body will become. signaling over long distances can only happen if the "intermediaries" somehow cooperate. Some cells "signal" to other cells by releasing particular proteins ("morphogens") that encode instructions for other cells. Other cells (such as nerve cells) "signal" by touching their neighbors. Cyrille de Joussineau has discovered that the latter process is more widespread than originally believed. Signals can be sent over long distances by a chain of cells capable of growing filopodia, which are used both for moving around, for collecting information and (Cyrille de Joussineau's discovery) for sending signals. A list of research papers on cell signaling Evolutionary biologist Russell Gray of the University of Auckland (New Zealand) is placing the origin of Indo-European languages in Turkey. The family tree of Indo-European languages indirectly tells the story of how Indo-European people (Indians, Persians, Greeks, Celts, etc) spread around the world. Figuring out the place where the oldest Indo-European language arose is equivalent to finding out where the Indo-Europeans originally came from. The traditional hypothesis (relying on archeological evidence) is that the Indo-Europeans originated 5-4,000 years BC from a region at the border between Asia and Europe, near the Ural Mountains. This "Kurgan" horsemen then migrated both east (Persia, India) and west (Europe). The new theory places the birth of the Indo-Europeans much earlier (7-6,000 BC) and in Anatolia (modern Turkey). It was not a population that migrated, but the language itself that migrated following the spread of agriculture. Farmers in Anatolia invented something so precious (farming) that it quickly spread both east and west, taking the language with it. Gray and his collaborators employed statistical methods: since the differences between words are a measure of how closely languages are related, then the rate of linguistic mutations (the rate at which words change) is a measure of how old the root of a linguistic family is. This statistical method shows that the most "distant" relative of modern Indo-European languages is the ancient language of the Hittites, invented between 8,000 and 10,000 years ago. This was much earlier than the time when the Hittites became a power: the language was not spread by force, but must have spread peacefully, as a by-product of a more advanced civilization. October 2003 Inkha ("Interactive Neurotic King's Head Assembly") is a robot receptionist that works at King's College in London Inkha, driven by a number of motors controlled by a computer, is capable of moving in response to movement (as detected by cameras and sensors) She is an autonomous robot, so substantially different from the robots that perform repetitive tasks in an assembly line. Jon Simons at the Institute of Cognitive Neuroscience of London is studying the interaction between the medial temporal lobe and the frontal lobe in long-term memory. The medial temporal lobe encodes, stores and retrieves long-term memories. The frontal lobe contributes to encoding and retrieval, but does not seem to participate in the storage/indexing of memories. Ernst Fehr of the University of Zurich (Switzerland) is studying human altruism, a phenomenon that seems to defy the principles Darwinian competition. He contrasts "reciprocal altruists" (widely found in nature), that reward and punis cooperation or lack thereof based on their long-term interest, with "strong reciprocity", which is uniquely human, in which reward and punishment are largely independent of long-term interest. He believes that the solution to the apparent paradox of altruism lies in cultural evolution and gene-culture co-evolution. (Fehr's article for Nature). Nature's focus on RNA interference collects a number of articles on the topic. RNA interference (RNAi) is a process (identified in plants and worms) that causes genes to be "silenced" so that they don't express themselves. This could have far-reaching applications in medicine. William Ruddiman at the University of Virginia (Charlottesville, USA) has estimated the effects on climate of human activities from the beginning of agriculture (8,000 years ago) to today, and decided that deforestation and irrigation caused the release of enough greenhouse gases into the atmosphere to actually change weather patterns (rising the global temperature by an average of 0.8§C, thus avoiding an impending ice age that never took place). Ruddiman examined records of greenhouse gases in ice cores dating back 400,000 years, and found that the cyclical fluctuations on planet Earth were altered starting about 8,000 years ago (carbon dioxide and methane into the atmosphere should have been declining steadily for the last 10,000 years, but instead have been rising for the last 8,000 and 5,000 years respectively). The correlation between solar radiation (caused by changes in the Earth's orbit) and methane in the atmosphere stopped working 5,000 years ago. Ditto for the rise of carbon dioxide (also now out of synch with solar radiation), which started 8,000 years ago (way before the industrial revolution). The only possible explanation for these two anomalies is human activity: deforestation caused the increase in carbon dioxide, and rice paddies and livestock caused the increase in methane. (Incidentally, the "little ice age" that started around 1300 and lasted a couple of centuries coincides with a reduction of agriculture, namely the plague that spread from China to Europe). September 2003 Kun-Liang Guan of the Life Sciences Institute (Michigan, USA) has identified several groups of "guidance cues" (which are actually proteins such as netrins1-3, semaphorins4, 5, ephrins6-8 and Slits9) that guide neurons and axons to their appropriate destinations during brain development. The nervous system is manufactured through a lengthy process (both during the embryonic stage of the foetus and during the first few years of life) in which cells must migrate to their "correct" locations and axons have to create the "correct" connections. These two processes (neural migration and axon pathfinding) are guided by those "cues", which either either attract or repel axons and neurons. Asish Basu of the University of Rochester and his colleagues claim that a meteor on Antarctica caused mass extinction of about 90% of life forms on Earth 250 million years ago (the Permian-Triassic boundary). August 2003 A team led by Eric Lander at the Broad Institute (Boston, USA) is on its way to complete the sequencing of the chimp's genome. The chimp's genome is almost 99% identical to the human genome, but humans are obviously quite different from chimpanzees. Comparing the two genomes may help figure out what causes the huge difference between the two species. July 2003 Since the circadian rhythms is basically the rhythm of day and night (sunlight and darkness), it has long been believed that the biological clock depends on exposure to light, and specifically on exposure "of the yes" to light. But Dan Oren, a psychiatrist at Yale University, has argued that blood is the messenger that carries the light signal from the skin to the brain. So Scott Campbell and Patricia Murphy of Cornell University Medical College have used bright light applied to the back of people's knees to reset the human internal clock. These experiments seem to confirm Oren's theory. The problem is that we don't quite know what causes and maintains the biological clocks. The hypothalamus is widely considered to be the location of the circadian pacemaker in mammals, but proteins called "cryptochromes", that are spread throughout the body, are involved in detecting changes in light and setting the body's clock. In 1998, both Joseph Takahashi's team at Northwestern University and Jeffrey Hall's team at Brandeis University demonstrated that the protein cryptochrome (the same protein that triggers plant growth by responding to light in the blue-to-ultraviolet part of the spectrum) acts as a transducer by which light drives the molecular machinery that generates circadian rhythm. Genetics is adding some interesting data. In 1971, the first circadian gene was discovered in the fruit fly. In 1997, Joseph Takahashi of Northwestern University discovered that the biological clock is related to the periodic expression of genes. Light, via a "photic entrainment pathway" (a series of photopigments and phototransduction pathways), triggers the clock genes. An increasing number of mammalian genes have been shown to be regulated by the clock genes. Once activated, the clock-controlled genes are expressed and are synthesised into proteins. We now know that "the fruit fly's clock consists of a core system of four regulatory proteins that interact to give the clock periodicity. The cycle begins when two of these proteins, CLOCK and CYCLE, bind together and increase the production of two other proteins, PER (periodic) and TIM (timeless), the levels of which slowly accumulate over time. When enough PER and TIM are made, they disable the CLOCK-CYCLE complex, slowing their own production and signaling the end of the cycle." ( "National Institute of Mental Health") The team of David Julius' Lab at UC San Francisco is studying how we perceive heat, the chemical process that leads to the sensation of pain related to heat. This could lead to new clinical strategies for pain management. Ardem Patapoutian and others at the Scripps Research Institute at La Jolla, California "thermosensation", the way we react to changes in temperature. They have identified the "thermoTRPs" (thermal Transient Receptor Potential ion channels) that transform thermal information into electrochemical signals to the brain. This transmission is mediated by the dorsal root ganglia along the vertebral column. The neurons of this ganglia are highly specialized to sense distinct ranges of temperatures, so that distinct groups of sensory neurons convey specific sensory information via dedicated pathways to the brain. Researchers at the University of Southern California, Los Angeles (Mihail Bota, Hong-Wei Dong and Larry Swanson) have inaugurated a Knowledge Management System, the "Brain Architecture Management System" (BAMS), that will act as both a repository of information about brain structures of different species and a tool (an inference engine) for analyzing the architecture of brain networks. The system has been initialized with thousands of data collected from the scientific literature, particularly about the connections between brain regions. The team of Laura Cousino Klein at Penn State University has found that nicotine withdrawal impairs time perception in smokers. Basically, they tested how well smokers and non-smokers estimate can estimate a time interval. Differences are minimal. But when smokers are kept from smoking for a day or so, they begin to make erroneous estimates, up to 50% shorter. June 2003 Thanks to new technologies for scanning the brain, scientists at the Panum Institute of Copenhagen have been able to measure blood flow in the brain corresponding to both inhibitory and excitatory stimuli. Contrary to expectations, both kinds of stimuli cause blood flow in the brain to increase. This is a puzzling finding that probably means we don't really understand what we "read" in the brain's activity when we scan it. May 2003 Audie Leventhal of the University of Utah claims that a shortage of the GABA neurochemical in the visual cortex causes the decline in visual functions that accompanies ageing. The problem would not be in the eye, but in the brain. More specifically, Leventhal claims that GABA-mediated inhibition in the visual cortex degrades with age, because somehow production of GABA tends to slow down as the organism gets older. The function of GABA seems to be to protect the brain from unnecessary overload of signals. When GABA declines, the brain is overwhelmed by signals that are actually confusing, to the point that it may not be able to "think" and "see" properly anymore. Incidentally, some tranquilizers (Valium, Xanax, Librium) do increase the levels of GABA in the brain, but no correlation with improved vision or thinking in older humans has ever been recorded. The French neuroscientist Olivier Houde` is studying the neural foundations of logical and mathematical cognition (paper) in an attempt to clarify what logic and mathematics are (in our brain) and how they emerge and evolve. March 2003 Researchers at the National Institute for Medical Research are studying why and how neurons decided that they have to stop dividing. In theory, cells should keep dividing forever. In practice, they seem to be programmed to stop dividing at some point in their life, and that "point" is what gives our nervous system its shape. There is some kind of self-regulation associated to neurons, and, since neurons are in principle all the same, that form of regulation must be specific to the region where they "reside". The researchers have determined how some embryonic neurons give rise to most of the neurons of the adult nervous system in the Drosophila larva. The results are intriguing, and still largely mysterious. Some proto-neurons divide for about 4 days and produce about 100 cells, whereas others divide for 22-40 hours and generate only 4-12 cells. The question, of course, is what tells a neuron "you are part of this region and therefore you are supposed to stop dividing right now". January 2003 Jared Taglialatela and Sue Savage-Rumbaugh of Georgia State University report that they have been able to train a chimpanzee to use sounds for 'banana', 'grapes', 'juice' and 'yes'. Monkeys are obviously able to communicate via symbols, but this would be the first time that they can communicate via sounds (i.e., "speak"). Other chimpanzees have already communicated using sign language. We know that the 'higher' cognitive skills of human beings are mainly due to the prefrontal cortex. Jacqueline Wood and Jordan Grafman of the National Institutes of Health in Bethesda (Maryland) believe that the representational "technique" used by the prefrontal cortex (rather than the processes that occur within it) can explain our ability to reason, speak, etc. In other words, it is the way we store our knowledge that enables us to do what we do with knowledge. Samuel Weiss at the University of Calgary believes that prolactin, a hormone that is released after sexual intercourse and during pregnancy, causes the birth of new neurons in the brain. November 2002 Joelle Bernier, a researcher from Quebec (Canada), has conducted experiments that show how neurons are created in adult brains. Until a few years ago, neurons were thought to be created only at childhood. Then we observed neurons being created in a part of the brain. Bernier's experiments show neurons being created in the amygdala of the adult brain. The amygdala is an important center for processing emotions, and in particular "fear". August 2002 Research on the origin and maintenance of biological diversity has led biologists to discover that diversity of animal species and diversity of human languages go hand in hand, i.e.: cultural and biological diversity are lowest and highest in the same places. In other words, areas with the most animal species also contain the greatest number of human languages. Danish biologist Carsten Rahbek , in collaboration with British biologists Andrew Balmford and Joslin Moore of Cambridge University, has created a database on the distribution of all African mammals, birds, snakes and amphibians, that lists about 4,000 species. By using this database, he can study patterns of species distribution and their relationship with human activity. It turns out that areas inhabited by many animal species are also the areas where humans speak many languages, and viceversa. Of course, the relationship could be a mere coincidence. Other factors influence biological diversity (i.e., the weather) and perhaps the same factors end up influencing language diversity. The Australian chemist Edith Sevick has conducted experiments that show it is possible to break the second law of thermodynamics at the level of atoms and molecules. The second law of thermodynamics is the one that introduced the popular concept of entropy: entropy can never decrease in a closed system. In other words, if the system is closed (i.e., it is not being operated upon by another system), it drifts towards absolute chaos and no information. A very good example of this law is that your house needs maintenance: problems don't fix themselves, you have to fix them. A system spontaneously loses "order" and "information", whereas order and information can be increased only by an external force. An alternative way of expressing this concept is that some energy is always lost when converting from one type of energy to another, i.e. whenever the system "does" something. The British physicist James Clerk Maxwell (famous for having unified electricity and magnetism and opened the way for Einstein's special theory of relativity) had already noted more than a century ago that the second law of thermodynamics is a "statistical" truth, not a mathematical one. A system is made of many particles. Properties due to the ensemble of particles are "statistical" because they simply express the fact that a "majority" of particles exhibit those properties (not necessarily every single particle does). Therefore the second law of thermodynamics does not completely rule out the possibility of decreasing entropy. What Denis Evans and Sevick has shown is that the second law of thermodynamics is continually being violated at the level of microscopic particles (albeit only for very short periods of time), although if you consider the whole system the second law of thermodynamics is always confirmed (see her paper). Sevick's study could eventually introduce a new fundamental property of nature, and a new fundamental limit. What her experiment shows is that, at some very small scale, machines would stop working the way they work at the scale we are used to. Thus, there would be a natural limit to miniaturization (machines would literally start working backwards if you make them "too small"). And this would, obviously, have an impact on things such as computers. June 2002 In the quest for an explanation of dark matter and dark energy, the American physicist Paul Steinhardt and the British physicist Neil Turok have proposed the Cyclic Universe Theory, according to which there is no "big bang" to begin with, and there will be no "big crunch" to end with. Space and time existed ever since and will exist forever. There is no beginning or end. The evolution of the universe is due to a series of "bangs" (explosive expansions) and "crunches" (contractions). The big bang that we observe today with the most powerful detectors of microwaves is simply one of the many expansions following one of the many contractions. Each phase may last a trillion years, and therefore be undetected by human instruments. The cyclic nature of the universe would be due to "negative potential energy", a concept arising from string theory, rather than General Relativity's spatial curvature. In principle, this is the same idea advanced by the QSSC (Quasi Steady State Cosmology) of British physicist Geoffrey Burbidge and his collaborators Fred Hoyle and Jayant Narlikar. In fact, it is more orthodox than it may sound. Totally lacking is Burbidge criticism of black holes, quasars and the cosmic radiation. The American neurologist Bradley Schlaggar has been studying the different use of the brain by children and adults. His theory is that the very same tasks are performed by children and adults using different brain regions. As the human brain matures, some functions are offloaded to other regions. Why this is happening and when it stops happening is the mystery that Schlaggar is trying to solve. It could be that some connections among brain regions are not mature enough in the early years of life. But why some regions would be better than others for performing some functions is still not clear. What is clear is that, as we grow up, we change the way we use our own brain. May 2002 "Ecological population genetics" is the study of why and how living beings are the way they are within the environment that they inhabit. Insect colonies (and particularly ant colonies) are a favorite subject to study because they tend to have the most complex social organization. They are typically divided into different castes with different functions. For a long time there has been a debate on how such castes arise. One theory is that they are determined by the environment: there is nothing at birth to differentiate a worker from a warrior, just like there is nothing genetically different between a human being who works in a factory and a human being who fights in a war. In this sense, society is basically "forced" upon the colony: environmental pressures force living beings to get organized in societies. Instead, Stanford Univ's biologists Deborah Gordon and Veronica Volny have recently shown that there is a genetic determination of who does what. While studying the caste system of the red harvester ant, they found out that a queen mates with different males and the offspring belongs to a caste or another depending on the male. The castes are a product of the sexual behavior of the queen. April 2002 German anthropologist Svante Paabo has found the first evidence of what causes the differences in behavior between chimpanzees and humans (who share 99% of their genes). In 1997 Paabo showed that the Neandertal man's DNA sequence falls outside the normal variation of modern humans. In other words, Neandertals were not our ancestors. Using a similar technique, biologists can show that the genes of chimpanzees and humans are mostly identical. It is a mystery why humans behave in such a different way. Their brains are amazingly similar. Proving that "pattern" and not "topology" determines what goes on inside the brain, Paabo's studies show that gene activity (i.e., production of protein) in the cerebral cortex of humans is five times more intense than in chimps. Human brains simply evolved five times faster than chimpanzee brains. Christof Koch and his team have been investigating the portion of the brain in charge of visual processing. The idea is that visual processing is a function that generates consciousness of something out of integrating so many different inputs, and therefore is a good indication of how consciousness works. Koch is looking for the "neural correlates" of conscious experience, i.e. the neural activity related to the creation of a conscious experience. Koch's articles basically detail his quest for the area in the brain where consciousness arises (see for example, this article) The problem is that every year there seems a new area that is also involved... March 2002 The South-African anthropologist Christopher Henshilwood has moved back the birthdate of thinking by about 40,000 years. Humans have existed for a very long time, but there is scant evidence that they were "thinking" until very recently. The cave paintings have been the strongest evidence yet for some kind of symbolic thinking (I paint something that refers to something else). In a Southafrican cave, Henshilwood discovered two pieces of ochre with geometric patterns, which could be symbolic artwork that would predate the oldest known cave paintings by more than 40,000 years. Some anthropologists and psychologists argue that the faculty of thinking developed suddenly, in a relatively short and intense burst of creativity, whereas others think that it developed gradually and slowly over many thousand years. If you believe that our evolutionary history parallels our developmental story (i.e., how we turn from children to adults) you tend to side with the former theory. If you believe that thinking followed the general patterns of anatomical evolution, you may side with the latter theory. The further back art objects go, the higher it is that the latter theory is right. An article on this finding In the 1950s, the Russian psycho-physicist Yarbus realized that human beings do not scan a scene in a raster-like fashion. On the contrary, we jump from one point to the next one, in an apparently random manner. We only fixated for a very short period on each point. A "saccade" is a rapid eye movement that occurs while we are awake. Saccades occur several times a second. Basically, our eyes continuously scan the environment. In order to do this, our eyes need to continuously "refocus". "Saccadic eye movements" are opposed to the "pursuit eye movements", the slow, smooth eye movements that follow a steadily moving target. Saccadic eye movements are interesting because it may tell us a lot about how our brain works and, in particular, about the other "rapid eye movement", the one that occurs while we are sleeping (see this introduction to eye movements, see this introduction to saccadic movements, see this seminar, and, for example, this paper). The mystery, of course, is how can we perceive a stable world when our eyes are continuously changing target (a phenomenon known as "visual stability"). We should be perceiving a rather messy and frantic world. The German neurologist Alex Thiele is studying neuronal activity related to saccadic eye movement. His findings prove that the brain regulates the saccadic eye movement and "suppresses" some of the information in order to present a world as stable as possible. Saccades have been found to be shortcuts to relevant information in the environment. Since we cannot store the entire world in our brain, we simply store pointers to what is truly important in the environment. When we need to retrieve information, we use saccades. Basically, we retrieve information as we need it, instead of storing it permanently in our brain. Yarbus already knew that, while apparently random, the pattern of saccadic eye movements depends on the cognitive task to be performed (on what information we need to retrieve). For example, when we need to identify someone, the saccadic eye movements focus mostly on the eyes and the mouth. These are the regions that we mostly rely on for face recognition. Saccadic eye movement is not a random sampling of the environment, but a highly specific indexing of relevant information in the environment. February 2002 The American neuroscientist Matthew Wilson from the Centre for Learning and Memory at the MIT is studying the way experience is represented and stored in the brain of rats. The idea is that one can examine the patterns of neural activity in the brain and relate those patterns to something that happened to the individual (rat) and that is being processed in the brain. The same studies can be applied to dreams. Dreams are widely believed to be a means to consolidate memories acquired during the day, by playing them against the genetic repertory and moving them from short-term memory to long-term memory. For example, patterns of neural activity in the hippocampus that occurred during the day will reoccur during sleep periods. By observing which neural patterns arise (and by correlating them to previous neural activity), one can actually guess what the rat is dreaming of. The American psychiatrist Gregory Berns (of Emory University) is studying the brain circuits that are responsible for impulsive behavior such as playing the stock market, gambling, rooting for a soccer team. It turns out these are the same brain circuits that evolved to help us cope with survival issues (food, sex, danger). Those brain circuits are largely outside the sphere of influence of your "conscious" experience. We react by "instict" to those survival issues. Our brain seems to be built in such a way as to avoid "thinking" about issues that are a matter of life and death. As we acquire data from our surroundings, some of them are first processed by the and are "perceived" only after a response has already been programmed. The fact that trivial chores, such as investing in the stock market or rooting for a soccer team, also fall outside "conscious experience" lends credence to the theory that "most" of our cognitive life is unconscious. Several cognitive scientists believe that we "think" only after we have already acted, and our self-awareness is a mere illusion. I pretend that I have been writing these lines because I wanted to, but in reality I wrote them under some kind of unconscious impulse and only afterwards do I realize that I wrote them. It all goes back to the circuits in the brain that pilot our behavior in the face of rewards. The circuits that assess "rewards" are driven by a chemical called dopamine, and are therefore referred to as the "dopamine system". In 1997 Swiss neuroscientist Wolfram Schultz developed a theory of how the dopamine system affects learning through the concept of "reward". Dopamine neurons respond to rewards. A good reward increases the activity of dopamine neurons, a mediocre reward has no effect on them and a disappointment (the opposite of a reward) depresses their activity. Basically, the dopamine system is an alarm bell. If the dopamine system is stable, the brain does not have to look into what has happened: the world is under control. If the dopamine system is subject to a change, then the brain has to look into what happened and "learn" something new: the reward signals that the action was a useful one, the disappointment signals that the action was a bad one. Whenever the dopamine system gets excited or depressed, some kind of learning occurs in the brain. While depevoled for survival purposes, the same dopamine system is vulnerable to "rewarding" signals from, say, the stock market and gambling. The American anthropologist Michael Alvard has advanced the theory that the social behavior of humans arose with the adoption of carnivorous habits. Hunting is a cooperative process that may have fostered the evolution of cognitive skills such as altruism and language, and even politics and economy. The transition from solitarty foraging to group hunting changed the environmenal pressure that early hominids were subject to. Alvard also points out that the distribution of meat had to be "fair" in order to motivate individuals to cooperate (each individual had to "gain" something proportional to his contribution to the hunt). In other words, hunters needed relatively complex behavior, compared with solitary foragers. January 2002 While studying the brain of monkeys, Ryohei Hasegawa of Kyoto University and National Eye Institute has discovered that neurons reflect past and predicted performance much more than they reflect current performance. (See their paper) Basically, the brain does not store current activity, but immediately computes future behavior in the face of a similar situation plus a "summary" of past events. Neurons are basically machines to predict the future. (See the debate on this experiment). Chris Goodnow of the John Curtin School (Canberra, Australia, (His home page) and his student Stephen Martin (His home page) are studying immunological memory, or how the immune system remembers. Since we have learned of so many analogies between the immune system and the brain, this research could lead to a better understanding of brain memory as well. There is a kind of cell that provides a sort of barrier to future infections. Martin is trying to understand this kind of cell. An abstract of their work). November 2001 The cell's cytoskeleton contains protein structures called "microtubules". We used to think that neurons had no inner structure, but now more and more attention is being paid to its internal structure and in particular to its cytoskeleton. The microtubules of the cytoskeleton could give rise quantum processes and account for free will, and this has started a whole school of thought about quantum consciousness. (Lots of information on the cytoskeleton at: Nature.com). Kazuhisa Kinoshita at the Max Planck Institute in Dresden is one of the researchers who are studying the behavior of microtubules. He has published a paper in which he describes the "dynamic instability" of these structures (they self-destroy rapidly) and shows how he has produced microtubules in vitro that are instead "well-behaved", a step towards understanding them better. Bose-Einstein condensates are exotic materials in which all atoms become one, they become indistinguishable. Some theories of consciousness (see my book, chapter on Consciousness) are interested in Bose-Einstein condensates because consciousness behaves like a Bose-Einstein condensate and one only has to prove that Bose-Einstein condensates are possible in the brain to make the connection. Unfortunately, so far Bose-Einstein condensates have been produced only for elements that hardly qualify as "thinking" stuff (rubidium, sodium, hydrogen, helium, lithium). Giovanni Modugno at the University of Firenze has successfully produced a Bose-Einstein condensate out of a mixture of rubidium and potassium atoms. This has added potassium to the list of condensable elements and, most important, the technique they employed promises to further expand this restricted family, thereby making Bose-Einstein condensates more common than we previously thought. There has been growing debate about the regeneration of neurons since it was first announced that our brain is capable of creating new neurons not only during development but also in adult age. This would mean that our brain is not just slowly "dying" but continuously being regenerated. David Kornack at the University of Rochester and Pasko Rakic of Yale Univ now report that they have found no evidence of new neurons in the neocortex of adult primates (the neocortex being where most of our "intelligence" resides). The only cells that are created are supporting cells that have little to do with "thinking". This is somewhat in contrast with previous experiments that showed growth of new neurons at least in the hippocampus. June 2001 Researchers at the Institute for Neuroscience in Baltimore report that a protein called "agrin" has been found to regulate the immunological synapse. This synapse is not the kind of synapse found in the brain: it represents the border between the organism and the antigen that has infected it. The immune system works thanks to two cellular systems, both of which involve cells called "lymphocytes". One kind of lymphocytes produce a circulating (i.e., mediated by body fluids) immune system derived from B-cells ("B" because they are derived from bone marrow cells). The other kind of lympohocytes produce a cellular (i.e., mediated by cells) immune system derived from T-cells ("T" because they are derived from the thymus). B-cell immunity includes the circulating antibodies, whereas T-cells act as coordinators and effectors of the immune system. The findings show that it is agrin that determines if and when a "T cell" signals. Agrin is so called because it is an "aggregating" protein:it induces the aggregation of signaling proteins, i.e. it helps in the "construction" of nervous pathways (or, better, "signaling domains"). It is released from the terminals of motor neurons and it is well known to be involved in the development of the nervous system. (Incidentally, it is also abnormality associated with Alzheimer's disease). This finding confirms that agrin is responsible for the creation of signaling domains in both immune and nervous system; and it sheds light on how it "regulates" immune-system cells. Given the similarities between immune and nervous system, it is likely that this research will also shed light on how the brain is built and regulated. www.humanbrainmapping.org is the website of the Organization for Human Brain Mapping (OHBM) a Boston-based organization dedicated to neuroimaging research and in particular to creating a neuroimaging database. Both the name and the mission mirror the Human Genome Project. Unfortunately, the neuroimaging community has not done a good job of sharing data. Therefore there isn't yet a global repository of brain images. If we needed any further evidence that our mind shows us only what it wants to show us, Yoram Bonneh, of the Smith-Kettlewell Eye Research Institute in San Francisco, has documented how tthe brain erases some aspects of the visual field.He prepared a computer screen with a swirling pattern of blue dots superimposed on some stationary yellow dots. To most observers, the yellow dots appear to come and go. But in reality the erasing happens in the mind, not the computer (see the story in Nature Magazine). Of course, one cannot rule out that similar "discarding" or even altering of reality do not occur more often, during our daily life. Bonneh's explanation of this "motion-induced blindness" is that our mind has a theory of the world and sensory inputs must conform with that theory or are discarded. The illusion may well be the result of a fight for supremacy between the circuitry of the brain that makes sense of the world as a whole and the circuitry of the brain that deals with sensory input, the former suppressing sensory input that conflicts with its theory the world. Andrew Cohen, Nima Arkani-Hamed and Howard Georgi have presented a theory on how the universe came to be a four-dimensional one. According to their theory, the universe may have started with just a single dimension: time. As the universe cooled down after the big bang, space was born with its three dimensions. Far from being eternal, space would merely be the stage on which particles interact: there is no space without particles. Particles came first, space was a consequence. A fundamental theory of spacetime must therefore start with particles, and then deduce space. This would represent a complete reversal of our cosmology, as dramatic as the one due to Copernicus centuries ago. In the beginning , after all, there was only a point. Whatever the universe was before the big bang, it did not have a spatial dimension: it was one dimension-less dot. The "big-bang" explosion caused a cooling of the temperature, and with the cooling things started (literally) materializing: particles, atoms, molecules, etc. These are moving objects, and they move in three dimensions. In a sense, each dimension corresponds to a level of energetic excitation. A little energy is enough to move in one direction, but only back and forth: the world has one dimension. A little more energy is needed to start moving sideways as well. Even more energy is necessary to move up and down while moving back and forth and sideways. A new dimension arises when the universe's energy allows movement of a new kind. Needless to say, the question is now: why three? Why not two or four? One reply could be that maybe we are still transitioning and that eventually a fourth spatial dimension will be born and then another and then another. (As a reminder, superstring theory presumes ten dimensions). Another question is: why were dimensions born in later stages of the universe if they require some energy and energy was maximum at the very beginning, in the infinite density and temperature of the (dimension-less) big bang? That requires some technical discussion on that "energy". But the bottom line is that we know some particles (the gluons that glue together quarks in protons) are very weak at high energies and very strong at lower energies.They "embody" energy that can do amazing things, but they will do them only at low energies. It would not be surprising if the same turned out to be true of all dimension-creating particles. Interestingly enough, this theory is relatively simple to test. If it is true, then elementary particles such as quarks and gluons should move in fewer dimensions when the conditions of the early universe are replicated inside colliders. Raise the temperatures and those particles should start moving only back and forth on a straight line. If we could raise the temperature to the level it was during the big bang (don't try this at home), particles should stop moving completely. May 2001 Kevin Warwick is professor of Cybernetics at the Reading University (UK). In 1998 he made the headlines by inserting a microchip in his arm and connecting it to the environment (his house). This way Warwick added a new type of interaction between his body and the environment. In September, Warwick plans to connect such a microchip with his nervous system to gather information about the sensations and the feelings associated with our mental life. First and foremost, Warwick wants to "store" information about our internal life. This will provide invaluable knowledge and possibly allow to neutralize some emotions (eg, pain). Note that Warwick is both the subject and the object of his experiments. The closer you get to consciousness, the less you can use external objects. Rats are great to figure out how conditioning works, but not ideal for figuring out how it feels to be human. Later, the same chip will be implanted in his wife. Once the two chips are connected, telepathy will become reality, as each of the two will be able to "feel" the emotions of the other. Cyberpunks will love the idea that same day we will exchange emotions just like today we exchange emails. February 2001 Despite the hype of the joint announcement about the completion of the human genome project, almost nothing has been completed. While the media have widely reported that the number of genes in humans is 30,000, this is only a hasty estimate by the parties who wanted to make the announcement as soon as possible. The estimate by Human Genome Sciences (http://www.hgsi.com/) still stands at 100,000. The fact that Human Genome Sciences is proceeding much slower than Celera does not mean that Celera did a better job. Celera candidly admits that most of the DNA appears to be "junk". That's another thing that the human genome project was supposed to explain. It is obviously not junk. It just takes time to figure out what it is. January 2001 Researchers have found strong evidence that dreaming is not a human exclusive and that dreaming helps consolidate memories. MIT researchers led by Matthew Wilson detected patterns of brain activity in sleeping rats that match their patterns of brain activity during day activity. The laboratory rats appear to be dreaming of the maze they were learning to navigate. The patterns of brain activity that were observed when the rats ran a circular maze were exactly duplicated while the rats were sleeping. The neural patterns are the firing of clusters of cells in the hippocampus, one of the main areas for memory formation and storage. The duplication was extremely faithful. One could pinpoint the place in the maze were the rat was dreaming of being. This finding is important to support theories such as Allan Hobson's and Jonathan Winson's, according to which the day's memories are "rehearsed" in the hippocampus during sleep and moved to long-term memory. In 1984 the austrialian geologist Simon Wilde extracted a 4.4 billion year old crystal from an ancient rock. That crystal, according to the American geologist John Valley, is now yielding information about the Earth's past. It may signal that oceans already existed. The birth of life is assumed to coincide with the birth of water, take or leave a few million years. So far, it was believed that we living beings are 3.85 billion years old (happy birthday :-), because oceans were presumed to be 3.85 billion years old, but this finding would push back that date by half a billion years. Biologists and chemists have long debated how life could have developed so "quickly" from the "primordial soup", since the chances of the right elements occurring at the right time in the right place at the right temperature are very low. But an extra half a billion years would greatly increase the chances that chemistry worked out some magic by itself. Neuroscientists and zoologists have failed to identify brain structures that are specialized for musical tasks (several structures seem to be implicated, and those structures are shared with other tasks such as language and reasoning), but their studies are showing that our brains are naturally adapted to music, and we share this property with most if not all vertebrates. This lends credibility to the thesis that music is a very ancient mechanism. First, music was one of the earliest cognitive functions performed by humans: musical instruments have been found (in France and Sweden) that are at least 50,000 years old. Thus, we were playing music way before we learned to paint, sculpt or write. Second, an analysis of sounds produced by birds and whales has shown that animals employ the same system of musical composition (rhythm, notes, harmony) that humans employ. While each animal has different anatomical structures that enable it to produce different kinds of sounds (especially whales, who boast a seven-octave range), all birds and mammals study so far tend to use the same "aesthetics". Animals tend to "sing in key" and to "rhyme". Their songs tend to employ the structure of commercial pop music (intro, refrain, bridge, refrain). That, of course, explains why we humans enjoy listening to birds singing. Animals employ counterpoint and "call and response" in a natural way. A bird's song is immediately picked up by another bird that joins in the jamming. Since those species have wildly different evolutionary ages, this phenomenon suggests that musical cognition arose very early in the development of vertebrates, way before humans were born. Prominent among cognitive-musical research are the works of the Canadian neurologist Isabelle Peretz (who has studied the neural circuits where musical perception occurs, as documented in "Le cerveau musical"). and the American composer Patricia Gray, whose recent article covers the universality of music. More information can be found at the Music Cognition page at Ohio State. December 2000 At CalTech, American scientists have showed that the senses are correlated beyond what we knew. They showed people (rapidly) two circles and asked them "how many circles did you see?" Most people said one, some people said two. Then they showed the same people the same two circles, but this time each circle was accompanied by a beep. Guess what. Nobody missed: everybody counted two circles. Now they showed them the same one circle, but there were still two beeps. Interesting: many people could sweat they saw two circles. So what we see is what we hear :-) Seriously, the integration of sensory data goes probably further than we thought. It is difficult to separate the components of a visual experience (you can't just see the yellow of a shirt, or its size, you see a yellow shirt of that size). Well, it seems that by the same token we can't really separate the components of the whole experience (eg, the vision from the sound). In the UK, British scientists are studying an evolutionarily-ancient amphibian that has a skeleton but a very primitive head. The question is "when and why did heads develop". It is not a purely academic question, since the head contains most of the nervous system, the thing we call "brain". How and why did so much control get centralized in one place? And why the head and not, for example, the foot? One theory is that the eye had a lot to do with it: the more complex the eye, the bigger the head. Another theory is that vertebrates "got" the head from shell-equipped parasites that eventually became part of the body via endosymbiosis and eventually took over the functions of control. It is a little weird that we would use the same organ for eating and breathing. What's the point of placing mouth and nostrils in the head rather than in the chest? It only increases the chances that something goes wrong.

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