A group of nerve cells in the brain displays a remarkable ability to halt all forms of movement, as revealed by a recent study conducted on mice. This finding contributes significantly to our understanding of how the nervous system exercises control over our movements.
When a hunting dog detects the scents of a deer, it sometimes completely freezes. This phenomenon can also be observed in humans who must focus intently on a complex task.
Now, a recent discovery contributes to our understanding of what happens in the brain when we abruptly stop moving.
If two statisticians were to lose each other in an infinite forest, the first thing they would do is get drunk. That way, they would walk more or less randomly, which would give them the best chance of finding each other. However, the statisticians should stay sober if they want to pick mushrooms. Stumbling around drunk and without purpose would reduce the area of exploration, and make it more likely that the seekers would return to the same spot, where the mushrooms are already gone.
Such considerations belong to the statistical theory of “random walk” or “drunkard’s walk,” in which the future depends only on the present and not the past. Today, random walk is used to model share prices, molecular diffusion, neural activity, and population dynamics, among other processes. It is also thought to describe how “genetic drift” can result in a particular gene—say, for blue eye color—becoming prevalent in a population. Ironically, this theory, which ignores the past, has a rather rich history of its own. It is one of the many intellectual innovations dreamed up by Andrei Kolmogorov, a mathematician of startling breadth and ability who revolutionized the role of the unlikely in mathematics, while carefully negotiating the shifting probabilities of political and academic life in Soviet Russia.
A model of human cortical development could be used to instruct novel computational learning approaches. Alysson Muotri, Phd, Sujeeth Bharadwaj, PhD, Weiwei Yang, and Gabrial Silva, MSc, PhD, discuss the promise, the problems, and the potential when biology and artificial intelligence meet. Recorded on 10/14/2021. [3/2022] [Show ID: 37556]
00:00 Start. 00:17 Introduction — Alysson Muotri, PhD, UC San Diego. 11:51 An Information Theoretic Approach to Learning — Sujeeth Bharadwaj, PhD, Microsoft. 30:44 An Alternate Approach to Collectively Solving Intelligence: Machine Learning to Artificial Intelligence — Weiwei Yang, Microsoft. 47:54 Organoids May Have Just the Right Amount of Complexity to Make Sense of the Brain — Gabriel Silva, MSc, PhD, UC San Diego.
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When a fragrance wafted through the bedrooms of older adults for two hours every night for six months, memories skyrocketed. Participants in this study by University of California, Irvine neuroscientists reaped a 226% increase in cognitive capacity compared to the control group. The researchers say the finding transforms the long-known tie between smell and memory into an easy, non-invasive technique for strengthening memory and potentially deterring dementia.
The project was conducted through the UCI Center for the Neurobiology of Learning & Memory. It involved men and women aged 60 to 85 without memory impairment. All were given a diffuser and seven cartridges, each containing a single and different natural oil. People in the enriched group received full-strength cartridges. Control group participants were given the oils in tiny amounts. Participants put a different cartridge into their diffuser each evening prior to going to bed, and it activated for two hours as they slept.
Scientists have constructed a comprehensive set of functional maps of infant brain networks, providing unprecedented details on brain development from birth to two years old.
The infant brain cortex parcellation maps, published today in eLife, have already provided novel insights into when different brain functions develop during infancy and provide valuable, publicly available references for early brain developmental studies.
Cortical parcellation is a means of studying brain function by dividing up cortical gray matter in different locations into “parcels.” Scans from functional magnetic resonance imaging (fMRI) are taken when the brain is in an inactive “resting” state, alongside measurements of brain connectivity, to study brain function within each parcel.
Neurons produce rhythmic patterns of electrical activity in the brain. One of the unsettled questions in the field of neuroscience is what primarily drives these rhythmic signals, called oscillations. University of Arizona researchers have found that simply remembering events can trigger them, even more so than when people are experiencing the actual event.
The researchers, whose findings are published in the journal Neuron, specifically focused on what are known as theta oscillations, which emerge in the brain’s hippocampus region during activities like exploration, navigation and sleep. The hippocampus plays a crucial role in the brain’s ability to remember the past.
Prior to this study, it was believed that the external environment played a more important role in driving theta oscillations, said Arne Ekstrom, professor of cognition and neural systems in the UArizona Department of Psychology and senior author of the study. But Ekstrom and his collaborators found that memory generated in the brain is the main driver of theta activity.
Researchers from Hebrew University of Jerusalem and UC Berkeley recorded electrical activity in the brains of epilepsy patients while showing them various images in an attempt to find out where persistent images are stored in the brain and how we consciously access those images. (Image credit: Hadar Vishne, Royal College of Art)
More than a quarter of all stroke victims develop a bizarre disorder — they lose conscious awareness of half of all that their eyes perceive.
After a stroke in the brain’s right half, for example, a person might eat only what’s on the right side of the plate because they’re unaware of the other half. The person may see only the right half of a photo and ignore a person on their left side.
New breakthrough in material design will help football players, car occupants, and hospital patients.
A significant breakthrough in the field of protective gear has been made with the discovery that football players were unknowingly acquiring permanent brain damage from repeated head impacts throughout their professional careers. This realization triggered an urgent search for better head protection solutions. Among these innovations is nanofoam, a material found inside football helmets.
Thanks to mechanical and aerospace engineering associate professor Baoxing Xu at the University of Virginia and his research team, nanofoam just received a big upgrade and protective sports equipment could, too. This newly invented design integrates nanofoam with “non-wetting ionized liquid,” a form of water that Xu and his research team now know blends perfectly with nanofoam to create a liquid cushion. This versatile and responsive material will give better protection to athletes and is promising for use in protecting car occupants and aiding hospital patients using wearable medical devices.
In a new study published in PNAS, the team took a page from cognitive neuroscience and built a modular AI agent.
The idea is seemingly simple. Rather than a monolithic AI—a single network that encompasses the entire “self”—the team constructed a modular agent, each part with its own “motivation” and goals but commanding a single “body.” Like a democratic society, the AI system argues within itself to decide on the best response, where the action most likely to yield the largest winning outcome guides its next step.
Images of thousands of Purkinje cells reveal that almost all human cells have multiple primary dendrites. These structures, when observed in mice, facilitate connections with multiple climbing fibers originating from the brain stem.
In 1906, the Spanish researcher Santiago Ramón y Cajal received the Nobel Prize for his trailblazing exploration of the microscopic structures of the brain. His renowned illustrations of Purkinje cells within the cerebellum depict a forest of neuron structures, with multiple large branches sprouting from the cell body and splitting into beautiful, leaf-like patterns.
Despite these early portrayals showing multiple dendrites branching out from the cell body, the enduring consensus among neuroscientists is that Purkinje cells possess only a single main dendrite that forms a connection with a lone climbing fiber originating from the brain stem. However, a recent study from the University of Chicago, recently published in the journal Science, reveals that Cajal’s sketches were indeed accurate — practically all Purkinje cells in the human cerebellum have multiple primary dendrites.
