Weekly Neuroscience Update

Credit: eLife (2023)

Researchers have investigated the shared and unique neural processes that underlie different types of long-term memory: general semantic, personal semantic, and episodic memory, suggesting that these memory types all use the same network of the brain, rather than relying on different areas of the brain altogether. This questions a previous theory that characterizes general semantic and episodic memory as two distinct systems. Instead, the authors suggest that different long-term memory types could be viewed as a spectrum, where they rely on activating the same areas of the brain at differing magnitudes.

Scientists can now pinpoint where someone’s eyes are looking just by listening to their ears.

Using a specialized device that translates images into sound, neuroscientists have shown that people who are blind recognize basic faces using the part of the brain known as the fusiform face area, a region that is crucial for the processing of faces in sighted people.

People with long COVID exhibit patterns of changes in the brain that are different from fully recovered COVID-19 patients, according to new research.

What is the mechanism that allows our brains to incorporate new information about the world, and form memories? New work led by Dr. Tomás Ryan from Trinity College Dublin shows that learning occurs through the continuous formation of new connectivity patterns between specific engram cells in different regions of the brain.

New research indicates that acoustic stimulation of the brain may ease persistent symptoms in individuals who have experienced mild traumatic brain injury in the past.

Scientists have discovered that Alzheimer’s-related changes in brain networks extend beyond memory and attention, impacting sensory and motor circuits. These findings challenge previous assumptions about Alzheimer’s effects.

A pivotal discovery in addiction science has found a correlation between microstructural deficits in the prefrontal cortex-habenula tract and the development and maintenance of addiction.

Researchers have unveiled a pioneering technique for charting the intricate conversations occurring within our brains. Such insights are key to decoding behavioral alterations in neurological disease patients. The innovative tool, CaMPARI, allows scientists to witness brain activity in real-time, marking active neurons red and inactive ones green. This breakthrough could offer pathways to better treatments and understanding of diseases like Alzheimer’s.

A team of neuroscientists has found evidence suggesting that the neural development of babies still in the womb is impacted by the language they hear spoken by their mothers as they carry them.

A new study has discovered a link between a new gene pathway and structural brain anomalies in some people who stutter into adulthood, opening up promising research avenues to enhance the understanding of persistent developmental stuttering.

Finally this week, researchers have developed a tool that simplifies the identification of errors in neural networks used for image recognition.

Weekly Neuroscience Update

Credit: Psychological Bulletin (2023)

A new study has provided the first clear picture of where language processes are located in the brain. The findings may be useful in clinical trials involving language recovery after brain injury.

Researchers have developed a model for studying one type of familial epilepsy, opening the door to understanding—and eventually targeting—the mechanisms that lead to the disorder and its associated fatalities.

A new study published in Nature Medicine sheds light on how biological sex influences brain function and its impact on the risk of various brain-related diseases.

A breakthrough technique developed by University of Oxford researchers could one day provide tailored repairs for those who suffer brain injuries. The researchers have demonstrated for the first time that neural cells can be 3D-printed to mimic the architecture of the cerebral cortex.

A research team has identified new potential treatments for children with rare genetic conditions of blood vessels, which cause severe, symptoms like seizures and impaired development.

Scientists have discovered new insights into how our brain stores episodic memories—a type of long-term, conscious memory of a previous experience—that could be critical to the development of new neuroprosthetic devices to help patients with memory problems, like Alzheimer’s disease and dementia.

A global blood test for concussion could be a step closer after a new study discovered specific proteins or biomarkers that can help diagnose concussions relatively quickly and accurately.

The brain circuitry that is disrupted in Alzheimer’s disease appears to influence memory through a type of brain wave known as theta oscillation, a team led by UT Southwestern Medical Center researchers report. The findings, published in Nature Communications, could help researchers design and evaluate new treatments for Alzheimer’s, a condition that affects millions of people around the globe and has no cure.

Finally this week, a new study reveals the role of vascular system cells—pericytes—in the formation of long-term memories of life events—memories that are lost in diseases such as Alzheimer’s disease. 

Weekly Neuroscience Update

Dietary phospholipid intervention could prevent brain aging by maintaining lipid homeostasis and enhancing synaptic plasticity. Credit: Wei Xiong et al.

A new review highlights the significant role of dietary lipids in preventing brain aging and cognitive decline. As the global burden of aging-related brain diseases, particularly dementia, continues to rise, this research offers promising insights into potential nutritional interventions that could improve brain function during aging.

Cerebrospinal fluid (CSF) leaks may be one of the mechanisms that link traumatic brain injury (TBI) with dementia, according to a new hypothesis.

Short-term exposure to air pollution may be linked to an increased risk of stroke, according to a meta-analysis published in Neurology. Short-term exposure was defined as occurring within five days of the stroke.

People with a higher cumulative estrogen exposure throughout their life may have a lower risk of cerebral small vessel disease, according to a new study.

New research is painting a clearer picture of the early signs of multiple sclerosis (MS), showing that people are nearly twice as likely to experience mental illness in the years leading up to the onset of the disease.

Increased TV/DVD screen time at 1 and 2 years of age negatively affects developmental performance at 2 and 3 years of age, according to a study published in JAMA Pediatrics.

Whether you are an early bird or a night owl, your internal clock plays a critical role in maximizing your mental performance, according to a recent study. This effect is so strong that it can significantly impact academic performance for adolescent students and the results of brain health assessments for older adults.

Researchers are using ultra-high field 7 Tesla MRI to provide a better understanding of how sleep is regulated.

A new study suggests a common brain network exists among people with substance use disorder. By evaluating data from across more than 144 studies of addiction, the team found abnormalities across substance use disorders mapped to a common brain network across substances and lesion locations, suggesting a potential brain circuit to target with neurostimulation therapies.

Finally this week, people differ significantly in their memory performance and researchers have now discovered that certain brain signals are related to these differences.

Weekly Neuroscience Update

A new study sheds light on the neural underpinning of subjective odor perceptions.

New research has found that cognitive behavioral therapy (CBT) can significantly reduce the burden of fibromyalgia in part by reducing pain-catastrophizing, a negative cognitive and emotional response that can intensify pain through feelings of helplessness, rumination and intrusive thoughts. This finding is backed by neuroimaging data, evidencing reduced connectivity between regions of the brain associated with self-awareness, pain and emotional processing.

Researchers have discovered how an active form of a gene present in 75% of the human population works to protect the brain against neurodegeneration.

A recent study provides new insight into the relationship between the release of the neurotransmitter dopamine and decision-making processes. The scientists found that when dopamine is released, decisions are made faster, but tend to be more inaccurate.

A new study recently published in JAMA Neurology provides insights into the complex and intricate relationship of contact sports and the risk of dementia.

A team of leading clinicians, engineers, and neuroscientists has made a groundbreaking discovery in the field of treatment-resistant depression. By analyzing the brain activity of patients undergoing deep brain stimulation (DBS), a promising therapy involving implanted electrodes that stimulate the brain, the researchers identified a unique pattern in brain activity that reflects the recovery process in patients with treatment-resistant depression.

Scientists have revealed how the effects of psychosis spread throughout the brain.

Researchers have identified new regions of the brain crucial to the formation of long-term memory, challenging the conventional notion that the hippocampus is central to memory consolidation, by demonstrating that a different set of brain networks play a role.

Finally this week, scientists have revealed the molecular structure of a type of receptor that’s crucial to brain development and function.

Weekly Neuroscience Update

Credit: Nature (2023)

A new study has identified the link between memory and appetite.

Scientists have made a ‘paradigm shifting’ discovery on the mechanisms required for learning and memory that could lead to new therapies for Alzheimer’s disease and potentially Down syndrome.

Researchers have analyzed which physiological indicators recorded when watching a movie can predict the audience’s assessment. It turned out that the activity of zygomaticus major (the “smiling muscle”), heart rate variability and EEG indicators can tell us most about the viewer’s impression of the movie.

The largest genetic study of its kind has discovered specific changes in our DNA that increase the risk of developing epilepsy.

Researchers found that the skin, not pre-existing genetic programming, instructs nerve cells on how to mature for specific sensory tasks. The findings showcase that skin cues determine whether nerve endings develop to detect sensations in hairy or hairless skin. If corroborated by further research, this discovery could pave the way for therapies to mend damaged nerves or better comprehend congenital neuropathies.

A new study has explored the link between infant birthweight, gestational age and future cognitive problems.

Researchers have successfully developed temporary, organic electrodes that can be seamlessly integrated into biological systems. The method opens up a future where bioelectronics can be implanted in and removed from the body without surgery.

New research shows wildfire smoke impacts on the brain.

A new study has found that, among a sample of 152 young athletes exposed to repetitive head impacts (RHI) who were under age 30 at the time of death, 41.4% (63) had neuropathological evidence of CTE, a degenerative brain disease caused by RHI.

New research supports the idea that the brains of older adults who maintain physical fitness by engaging in regular strenuous exercise more closely resemble those of younger adults.

Researchers have succeeded in transforming brain signals into audible speech. By decoding signals from the brain through a combination of implants and AI, they were able to predict the words people wanted to say with an accuracy of 92 to 100%. Their findings are published in the Journal of Neural Engineering.

Finally this week, a virtual reality study has revealed a link between a sense of presence and cognitive abilities.

Weekly Neuroscience Update

Smaller Left vmPFC was associated with future smoking. Credit: Nature Communications (2023)

Levels of gray matter in two parts of the brain may be linked to a desire to start smoking during adolescence and the strengthening of nicotine addiction, a new study has shown.

Researchers have enabled machine learning to accurately predict Parkinson’s disease subtypes using stem cell images. This breakthrough showcases computer models classifying four Parkinson’s subtypes, with top accuracies reaching 95%. This could revolutionize personalized medicine and aid in more targeted drug research for Parkinson’s.

A large international team of medical researchers has found that the severity of COVID-19 infections in children over the course of the pandemic varied by age and viral variant.

Researchers have illuminated how our brain maintains focus amidst distractions. Their study identifies “visual-movement” neurons in the lateral prefrontal cortex (LPFC) that use coordinated activity called “beta bursts” to suppress distracting stimuli and ensure attention remains on rewarding tasks. This discovery gives a deeper understanding of cognitive focus and offers insights into disorders like ADD and OCD.

More cases of children born with abnormal brain development may have genetic explanations than previously thought, according to a recent study published in JAMA Neurology.

Hearing impairment may cause difficulties in social interactions, but new research indicates that social struggles experienced by deaf individuals are likely not due to brain alterations, but rather due to non-supportive environments.

Scientists have identified a series of processes that help the brain adapt to damage caused by breakdowns in circuits that govern movement, cognition and sensory perception.

For the first time, researchers have discovered that the ventral tegmental area (VTA) of the brain—a key structure involved in motivation and reward appreciation—has altered connectivity patterns with specific brain regions in patients with obesity. Individuals with obesity have hyper-connectivity of the VTA with part of the ventral occipitotemporal cortex (visual processing for food images) and hypo-connectivity with the left inferior frontal gyrus (associated with cognitive control), according to a new study in Obesity.

Researchers have identified a key pathway, involved in inflammation, which appears to be activated in people with long COVID who have symptoms of “brain fog.”

Using a novel approach of precision neuroimaging and high-resolution functional magnetic resonance imaging (fMRI), a team of neuroscientists and physicists have discovered previously unknown cortical networks and shed light on the anatomical organization of the human memory system.

A pioneering scientific study has shown that the effects of multiple concussions in rugby players continue to have an impact on their brain even in retirement. 

Researchers have coupled the measurements of brain waves associated with disorders of consciousness (DoC) with glucose usage in specific brain areas, identifying where in the brain the waves might be generated.

A new study shows that brains with Alzheimer’s disease have subnormal levels of important dietary antioxidants.

A breakthrough project mapping brain changes in nearly 1,300 people diagnosed with six different types of mental illness has revealed the extraordinary diversity of brain changes found in people with conditions like major depression and schizophrenia.

Researchers have unveiled a promising link between adult education and reduced dementia risk. 

Neuroscientists have shown that adversities permanently change the functioning of the brain. Furthermore, an aberrant reaction of the brain to adversities is related to anxiety symptoms. This may have predictive value for the development of psychiatric disorders.

Finally this week, a new study identifies sex differences in the brain cell types responding to stress.

Unraveling the Intricacies of Working Memory and Cognitive Processing

When we engage our working memory, we temporarily retain information in our brain. A team of researchers has now demonstrated that the key to understanding working memory relies not only on what one is storing in memory but also why – highlighting the “working” aspect of working memory, which underscores the purpose of storing information in the first place. Specifically, the study focuses on both how we store the visual properties of our memories in the occipital lobe, where our visual system resides, and on how the neural codes that store those memories change over time as people begin to prepare a response that depends on the memory.

In the study, the response simply required people to look where they remembered an object that disappeared several seconds ago. This sheds light on the intricate interplay between memory formation and the cognitive processes that guide our actions. As you read this sentence, for example, your working memory holds the words temporarily, and this could influence how you interpret the information and potentially respond to it. The importance of working memory to many of our cognitive abilities is well known, but less clear are the neurological machinations driving this process.

According to conventional textbook theories, the encoding patterns within our working memory remain constant over time. This signifies that the neural activity pattern responsible for storing a specific visual memory remains unchanged from its initial encoding, regardless of whether it’s been a mere second or a substantial 10 seconds. These intricate neural activity patterns serve as the repositories of visual memories, effectively forming a temporal bridge that connects a past stimulus with a forthcoming memory-guided response.

However, recent investigations involving animals have revealed that the neural patterns responsible for memory are notably more fluid. In fact, the stability of memory codes has been brought into question, as they seem to exhibit perplexing changes over time.

To delve into this phenomenon, researchers Li and Curtis, known for their prior breakthroughs in deciphering the organization of our working memory within the brain, developed innovative techniques. Their goal was to not only quantify the shifting neural dynamics but also to render these dynamics intelligible. To achieve this, they projected intricate neural measurements onto a simple 2D plane, akin to the screen of a laptop or smartphone.

The accompanying video vividly illustrates the progression of neural activity during a working memory trial. Initially, a cluster of activity emerges, encoding the briefly presented visual target (depicted as a pink circle), evident in both the primary visual cortex (V1) and a higher-level visual area (V3AB). In V3AB, this activity cluster remains fixed at the target location throughout the memory retention period. However, within V1, a line of activity evolves during the delay period between the individual’s current gaze direction (indicated by a pink cross) and the intended eye movement after the delay.

The researchers posit that this evolving line represents the projected path of the intended gaze shift that individuals are mentally rehearsing but have yet to execute.

While prior research had documented the dynamic nature of neural activity during working memory, the underlying cause for these dynamics had remained enigmatic. The latest findings help shed light on this puzzle. They suggest that these dynamic neural patterns are manifestations of the transformation of past sensory experiences—what has recently been perceived—into anticipated behaviors guided by memory—what actions might be taken based on that memory.

More information: Clayton E. Curtis, Neural population dynamics of human working memory, Current Biology (2023). DOI: 10.1016/j.cub.2023.07.067www.cell.com/current-biology/f … 0960-9822(23)01039-4

Weekly Neuroscience Update

Scientists have shown that the hypothalamus, a key region of the brain involved in controlling appetite, is different in the brains of people who are overweight and people with obesity when compared to people who are a healthy weight.

Researchers have shown in lab-based experiments that variants of SARS-CoV-2, the virus that causes COVID-19, can affect the blood-brain barrier and damage brain cells in different ways.

Unlike previously thought, speech production and singing are supported by the same circuitry in the brain. Observations in a new study can help develop increasingly effective rehabilitation methods for patients with aphasia.

Scientists have discovered an additional potential cause of the genetic mutations that result in rare conditions such as Huntington’s disease (HD).

Neuroscientists report the first results from experimental tests designed to explore the idea that “forgetting” might not be a bad thing, and that it may represent a form of learning—and outline results that support their core idea.

The largest-ever study of the genetics of the brain—encompassing some 36,000 brain scans—has identified more than 4,000 genetic variants linked to brain structure.

A first-in-human trial of deep brain stimulation (DBS) for post-stroke rehabilitation patients has shown that using DBS to target the dentate nucleus—which regulates fine-control of voluntary movements, cognition, language, and sensory functions in the brain—is safe and feasible.

New research finds that genetic risk for higher blood pressure even in those in their 40s and 50s may contribute to poorer cognitive function.

An obscure class of molecules, part of the vast system that helps the human body distinguish “self” from “non-self,” may also hold the key to stopping SARS-CoV-2 from commandeering healthy cells, scientists have found in a series of experiments.

Scientists have discovered how HIV hijacks intracellular processes to proliferate and contribute to neurodegeneration, according to a new study published in Nature Communications.

Researchers have discovered a potential breakthrough for people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), marked by extreme exhaustion, post-exertional malaise and cognitive issues.

Finally this week, in a small, exploratory study, levels of certain types of microbes in babies’ guts have been shown to be associated with performance in tests of early cognitive development.

Weekly Neuroscience Update

Factors associated with healthy aging in Latin American populations. Credit: Nature Medicine (2023)

Researchers at Trinity College Dublin studying the factors influencing healthy brain aging in Latin American and Caribbean (LAC) countries find the lessons learned there, can also be applied to home.

Immune cells in the brains of people who had Alzheimer’s disease appear to behave differently than those who had healthy brains for their age, according to an analysis of the cells’ gene activity. The finding suggests it might be possible to treat Alzheimer’s disease by altering the behavior of these cells.

The longer a person has type 2 diabetes, the more likely they may be to experience changes in brain structure, a new study finds.

Using human “mini-brain” models known as organoids, scientists have discovered that the roots of autism spectrum disorder may be associated with an imbalance of specific neurons that play a critical role in how the brain communicates and functions. The specific cells are known as excitatory cortical neurons.

Psilocybin, the active ingredient in psychedelic mushrooms, shows promise for the transitional treatment of episodic migraines in early clinical trials, according to a recent review.

Researchers have discovered that a neural marker of error detection in the brain’s visual system previously considered pre-attentive may actually require attention and that subtle visual irregularities may be revealed by other neural markers.

A new study has demonstrated that self-organization of neurons as they learn follows a mathematical theory called the free energy principle.

The neural network related to speech is mostly located in the left cerebral hemisphere, while singing has been primarily associated with the structures of both hemispheres. However, a new study indicates that the left hemisphere has a greater significance, including in terms of singing, than previously thought.

A new digital headset designed to measure alterations in brain function could change decisions about how quickly an athlete is ready to return to play after a concussion.

A new study suggests stimulating the sense of smell can boost memory. Older adults exposed to odors while they slept performed better on verbal memory tests and showed improved function in a brain pathway that supports memory formation, according to the study, published in the journal Frontiers in Neuroscience.

Finally this week, researchers have shown that machine learning can accurately predict subtypes of Parkinson’s disease using images of patient-derived stem cells.

Weekly Neuroscience Update

A new study reveals that individuals with stronger ‘mindreading’ abilities, or the capacity to understand others’ feelings and intentions, are more successful in cooperative tasks. This trait, also known as ‘theory of mind,’ is not directly tied to intelligence and can potentially be improved through training programs.

Researchers have identified proteomic changes associated with forms of Alzheimer’s disease.

People in their eighties who can recall everyday events and life experiences as well as someone 20 to 30 years younger—known as superagers—are also more likely to have greater movement speed than typical older adults. They also have lower rates of anxiety and depression, according to a new study published in The Lancet Healthy Longevity journal.

A research team has developed a tool that counts brain lesions in seconds.

A new study has found that the frequency and duration of naps in infants are an indication of their cognitive needs. According to the research, infants with smaller vocabularies and poorer cognitive abilities tend to nap more frequently.

Researchers have discovered that myo-inositol, a small cyclic sugar molecule found in breast milk, plays a crucial role in promoting neuronal connections in infants’ brains.

Neuroscientists have proposed a fresh perspective on systems consolidation, the process by which certain memories are moved from the hippocampus to the neocortex for long-term storage. Their theory, backed by a mathematical neural network model, posits that the consolidation of memories depends on their generalizability, not age. This theory suggests a new memory, which is a generalization of previous memories, is created during consolidation.

Researchers have utilized artificial intelligence to uncover the promising potential of extra virgin olive oil (EVOO) in combating Alzheimer’s disease (AD).

New research heightened light sensitivity in Alzheimer’s patients to “sundowning,” a worsening of symptoms late in the day, and sleep disruptions that may advance the disease. This fresh understanding of biological clock disruptions in Alzheimer’s could aid the creation of treatments and symptom management. Light therapy could potentially regulate erratic sleep patterns caused by altered circadian rhythms.

Finally this week, scientists have identified a group of nerve cells in the midbrain, which, when stimulated, can suspend all movement, akin to setting a film on pause.