|
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
Click here for the index of all years
December 2022
- Karunesh Ganguly's team at UC San Francisco has elucidated how motor memory is consolidated during sleep paper)
- Kyla Shea's team at Tufts University has discovered that vitamin D is in brain tissue, and the level of this vitamin could predict cognitive decline, i.e. cognitive decline among older people seem to correlate with lower levels of vitamin D. (paper)
- Flavia Rosianu's team at the Francis Crick Institute has discovered two enzyme proteins (kinase enzymes NDR1 and NDR2) that are key to the the health of neurons. Deleting the genes that encode those proteins leads to neural degeneration in mice. (paper)
- Joseph Cichon at the University of Pennsylvania has discovered that ketamine, a substance that has been used for decades as an anesthetic and also as an antidepressant, has the power to disable neurons that are active and to wake up neurons that are sleeping, therefore resetting what is going on in the brain. (paper)
- Kazuhiro Nakamura's team at Nagoya University has identified neurons that work to maintain the body temperature at 37 degrees in mammals: it's the EP3 neuronal group in the preoptic area of the brain. (paper)
November 2022
- Hee-Sup Shin at South Korea's Institute for Basic Science has discovered hints to the neural processes that create empathy in mice. He was able to induce empathy in mice by synchronizing neural oscillations in the right hemisphere of the brain. Key to empathy is the 5-7 Hz rhythms in the ACC-BLA circuit. (paper)
- Melina Hale's team at University of Chicago is studying the nervous system of octopuses, one of the most complex in nature but also significantly different from the human one. She discovered that multiple nerve cords connect the arms of octopus". It's a different way to arrange a nervous system. (paper)
October 2022
- Inbal Ravreby at Israel's Weizmann Institute of Science has found evidence
that humans too, like most
terrestrial mammals, are subconsciously influenced by smell when they pick friends, i.e. humans unconsciously calculate body odor similarity.
(paper)
September 2022
- Kaya von Eugen at Ruhr University Bochum in Germany has calculated the amount of energy consumed by the brain of birds. Brains are energetically costly organs in mammals: the human brain, which accounts for only 2% percent of the body's mass, uses a fifth of the body’s total energy consumption. The number is similar across all mammals, perhaps indicating that there's a limit to how big a brain can be in a mammal. However, the brains of birds are much denser than the brains of mammals, i.e. birds have higher numbers of neurons than mammals do. Kaya von Eugen has discovered that neural tissue in the pigeon consumes three times less energy than the one in mammals, i.e. less glucose per gram per minute. (paper)
- Nenad Sestan's team at Yale University has searched the dorsolateral prefrontal cortex (dlPFC), a brain region that is unique to primates, for clues on what makes the human brain unique. They analyzed its cell types and found 109 cell types that we share with other primates and five that are rare. In particular, a type of microglia seems to be exclusive to humans or, at best, shared with chimps. The human microglia contains gene FOXP2, which creates a protein called "forkhead box P2", which has always been suspected to be important for brain development. (paper)
August 2022
- Eti Ben Simon's team at the UC Berkeley showed that sleep-deprived people tend to be more selfish (paper)
- Neurogenesis, the process that produces new neurons in the brain, generates new neurons from neural stem cells. We now know that neurogenesis continues throughout a person's life. Several studies seem to prove that neurogenesis is impaired in Alzheimer patients, particularly in the hippocampus, a region that is crucial for storing and retrieving memories. Hongjun Song's team at Penn University's Perelman School of Medicine is one of the studies that has confirmed the presence of "immature neurons" in the hippocampus (paper). A study from Beijing Normal University also analyzed hippocampal neurogenesis across the lifespan of macaques (paper). Orly Lazarov's team at the University of Illinois showed that increasing neurogenesis in mice with Alzheimer’s disease reduces their memory weakness. They augmented neurogenesis by deleting the Bax gene via a genetic editing process called CreERT2. Boosting neurogenesis could be a viable strategy for treating Alzheimer’s disease. Conversely, when they "inactivated" immature neurons, the memory performance of the mice reversed. (paper). That Bax-deficiency prolongs cerebellar neurogenesis was discovered a decade earlier, for example in 2012 by Timothy Gershon's team at the University of North Carolina (paper).
July 2022
- Surya Ganguli's student Sadegh Ebrahimi, in collaboration with Mark Schnitzer's lab, has completed the first study of vision that recorded neural activity at cellular resolution across the brain's entire visual cortex, which will enable neuroscientists to track sensory processing from perception to action. This was achieved using genetically-engineered mice whose cortical neurons expressed a fluorescent protein (paper).
- Ellie Beam used artificial intelligence to analyze more than 18,000 fMRI research papers published over a 25-year period. Each paper is about a brain scan detailing which parts of the brain are involved in specific tasks. Beam's work consisted in generating a new classification of brain's functional domains. It has been assumed for at least a decade that the brain is structured in six major functional domains: the sensorimotor system, the cognitive system, arousal, a social domain, and two “valence” domains, one for “positive” thinking and one for "negative" thinking. The latter three are related to emotions. Beam, however, derived six different domains from her data-driven classification: memory, reward, cognition, vision, manipulation and language. The emotional features are integrated into circuits for memory and reward (paper).
June 2022
May 2022
- Juan Song at University of North Carolina discovered that stimulating the neurons of the supramammillary nucleus located inside the hypothalamus of the mouse brain causes an increase in the production of neural stem cells and spurs the creation of new adult neurons, or, better, adult hippocampal neurogenesis (paper)
- Botond Roska at the University of Basel studied the unconscious brain during general anesthesia. A group of cells in the cerebral cortex are more active during general anesthesia than when awake. What they do is puzzling: instead of each neuron sending different pieces of information, during anesthesia all layer 5 pyramidal neurons send the same piece of information. (paper)
- Tobias Langenhan and Manfred Heckmann, from Leipzig and Wuerzburg universities respectively, studied a genetic mutation, known as the CORD7 (cone-rod dystrophy 7) mutation, that damages a synaptic protein called RIM and causes blindness. It turns out that the same genetic mutation also causes to a cognitive improvement, a much increased transmission of information at the synapses resulting in increased verbal IQ and working memory (paper)
- Focusing attention is a brain process that depends to some extent on a communication loop between the anterior cingulate cortex (ACC) and the lateral posterior (LP) thalamus. Mriganka Sur's lab at MIT has published a detailed description of the flow of signals. The majority of inputs to the ACC come from frontal cortex regions that are involved in goal-directed planning and in visual processing, while inputs to the LP mainly come from deeper regions and include information about a broad range of factors. In other words, there are many inputs that are coming from non-sensory areas. (paper)
- Pawan Sinha at MIT verified that foetuses inside the womb start hearing sounds around 20 weeks of gestation, but their hearing is limited to low-frequency sounds and, more importantly, discovered that there is an advantage in limiting sound input to low-frequency sounds as the brain just started developing: it will be easier for the brain to perform certain tasks. Something similar has been shown (by the same team) for recognizing faces: initial exposure to only blurry faces improves the generalization ability of computer models to recognizing faces. Low-quality sensory input seem to be an effective way to "pre-train" the brain. (paper)
April 2022
- A study by Washington University surveyed 123,984 brain scans from 101,457 individuals (from newborn babies to centenarians) to determine the development of the brain over a lifetime (paper). You can follow the results of their research on paperthis website.
- Thomas Albright and Sergei Gepshtein at the Salk Institute have proposed a new way to look at the way neurons work in the brain. Traditionally we think of neurons as "particles" that interact by exchanging signals. A dual way to look at their work is to focus on waves of neural activity that interact by interfering, something like the interaction of light waves. Therefore one can study the brain by looking at partiles or, equivalently, at waves, which of course is precisely what happens in quantum mechanics with the wave-particle duality. (paper)
- Ido Kanter at Bar-Ilan University in Israel is proposing a revolutionary model of learning in the brain. Since Donald Hebb's studies of the 1940s, the standard model of neuroscience hypothesizes that brain learning consists in modifying the strengths of synapses whenever their connected neurons "fire". Deep-learning algorithms of artificial intelligence are based on this paradigm. Kanter argues instead that most learning takes place in dendritic trees rather than in dendritic leaves (the synapses). Kanter also shows that one single neuron can realize deep learning algorithms because a biological neuron is a much more complex entity than the artificial binary neurons of artificial intelligence. (paper)
- Neuroscientists and game developers, led by Antoine Coutrot at CNRS in France, got together to design a video game called "Sea Hero Quest" which was then used to measure the navigational skills of 397,162 people from 38 countries across the world. They found that people were better at navigating in environments that were topologically similar to the places where they grew up, which was to be expected, but also that people who grew up in the country side have better navigational skills than city-raised people. It is also known that exploring complex environments has a positive effect on hippocampal neurogenesis and cognition. Spatial navigation activates the hippocampus, and continuous navigation of a large complex environment increases posterior hippocampal volume. (paper)
March 2022
- Ann Graybiel's team at MIT have identified the neurons that encode the outcomes of actions: striatal projection neurons (SPNs), located in the brain’s anterodorsal striatum, encode associations between actions and both rewarding and aversive outcomes, i.e. two opposite pieces of information. The brain’s striatum is a region which has been implicated in reinforcement learning (punishment and reward, risks and benefits). It remains to be discovered how the information is processed to influence future decisions. (paper)
February 2022
- Scott Marek at Washington University has shown that most brain-imaging studies can only prove a loose correlation between a brain scane and cognitive behavior, a devastating blow to the current state of neuroscience (paper)
January 2022
- It is well known that a single memory in the brain (an "engram") is stored across many regions of the brain, i.e. distributed, and not localized in one specific place. In 1904 Richard Semon introduced the term “engram” to refer to the set of cells whose chemistry changes in response to a new memory. Retrieving a memory consists in reactivating ts engram. Semon realized that the engram is not localized but distributed across regions that are somehow connection. This is known as the "unified engram complex" hypothesis. In the 1930s Karl Lashley tried to localize the engram in rat brains but failed. In the 1940s Lashley's student Donald Hebb revived Semon's hypothesis in terms of "cell assemblies": when two cells are simultaneously active during an event, the connections between the two cells are strengthened ("neurons that fire together, wire together") and the set of all connected cells constitutes a "cell assembly". Major progress in studying engrams and cell assemblies had to wait until the development of modern electronic equipment. In 2009 Canadian neuroscientist Sheena Josselyn carried out loss-of-function studies ("Selective erasure of a fear memory", 2009) and at the same time Susumu Tonegawa's team at MIT carried out gain-of-function studies ("Optogenetic stimulation of a hippocampal engram activates fear memory recall", 2012). Maps of engrams have been developed with increased accuracy by Liqun Luo at Stanford ("Temporal evolution of cortical ensembles promoting remote memory retrieval", 2019) and Dheeraj Roy in Susumu Tonegawa's lab at MIT. They are derived from observation of which cells in each brain region were active at memory encoding and retrieval. These maps prove that an event activates simultaneously many engram ensembles distributed across multiple brain regions. (paper)
Click here for 2021 news
|