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

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.

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

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.

Weekly Neuroscience Update

Artificial Intelligence (AI), specifically GPT-4, was found to match the top 1% of human thinkers on a standard creativity test. The AI application ChatGPT, developed using GPT-4, excelled in fluency and originality in the Torrance Tests of Creative Thinking, a widely recognized tool for assessing creativity. This breakthrough finding indicates that AI may be developing creative ability on par with or even surpassing human capabilities. 

Researchers have identified a small structure in the brain, the anterior precuneus or aPCu, as a crucial component in establishing our physical self or “I”.

Taking good care of your teeth may be linked to better brain health, according to a study published in Neurology. The study found that gum disease and tooth loss were linked to brain shrinkage in the hippocampus, which plays a role in memory and Alzheimer’s disease. The study does not prove that gum disease or tooth loss causes Alzheimer’s disease; it only shows an association.

A new study has demonstrated for the first time that the diagnosis of multiple sclerosis (MS) can be significantly improved by additionally measuring the thickness of retinal layers in the eye.

Distinct, though neighbouring, areas of the brain are activated when processing music and language, with specific sub-regions engaged for simple melodies versus complex melodies, and for simple versus complex sentences, according to researchers.

New findings suggest that depression after traumatic brain injury (TBI) could be a clinically distinct disorder rather than traditional major depressive disorder, with implications for patient treatment.

If you’re sleep deprived, you will likely have a harder time remembering things than if you’re well-rested. But if you have good cardiorespiratory fitness, your memory may be less affected by the effects of sleep deprivation than others, according to a recent McGill study published in the journal Medicine & Science in Sports & Exercise.

Finally this week, even during sleep, the sounds that infants are exposed to can play a big role in language development, especially for babies at risk of language delays.

Weekly Neuroscience Update

Encouraging children to indulge in reading for pleasure can enhance their cognitive and mental health during adolescence, a recent study reveals. The study, involving over 10,000 young adolescents from the US, discovered that an optimal reading duration of 12 hours per week contributed to improved brain structure and mental health.

New research has investigated associations of adverse childhood experiences with changes in epigenetic age acceleration.

Researchers have discovered a new depression subtype, the ‘cognitive biotype,’ affecting 27% of patients who respond poorly to typically prescribed antidepressants. These patients struggle with planning, self-control, sustained focus, and suppressing inappropriate behavior, with brain scans revealing reduced activity in the regions responsible for these tasks.

A team of researchers has developed a predictive model to recognize patterns of persistent negative thinking, or rumination, using machine learning.

A new study involving over 22,000 people with Multiple Sclerosis (MS) has identified a genetic variant associated with the disease’s faster progression. The research discovered a genetic variant that significantly affects disease severity. This development brings us closer to understanding and combatting the progressive form of MS. The identified genetic variant accelerates disability, undermining patient mobility and independence over time.

Regularly finding time for a little snooze is good for our brain and helps keep it bigger for longer, say researchers.

Do intelligent people think faster? Researchers made the surprising finding that participants with higher intelligence scores were only quicker when tackling simple tasks, while they took longer to solve difficult problems than subjects with lower IQ scores. 

Finally this week, new research provides the first physiological evidence supporting the scientific theory of how the brain consolidates memory during sleep. 

Unraveling The Mysteries of Dopamine [Video]

Drawing on a recent groundbreaking study, this video explores how dopamine operates within the paradigms of Pavlovian and operant conditioning. The study provides new insights into the intricate functionality of this essential neurotransmitter in the brain.

Classical conditioning, also known as Pavlovian conditioning, involves learning through associations between a neutral stimulus and an unconditioned stimulus. In this process, dopamine release is triggered when the neutral stimulus becomes associated with a reward or positive outcome. Dopamine helps in reinforcing the connection between the neutral stimulus and the reward, making the association stronger.

Dopamine is closely linked to reward learning and motivation. It is involved in the brain’s reward system, which helps in reinforcing behaviors that lead to pleasurable experiences or rewards. Dopamine release signals to the brain that a certain action or behavior is beneficial and should be repeated. It provides a sense of satisfaction and drives motivation to engage in actions that lead to positive outcomes.

Watch the video to explore:

🔹 What triggers dopamine release?

🔹 The difference between classical and Pavlovian conditioning.

🔹 The pivotal role of dopamine in reward learning and motivation.

🔹 Which disease is associated with a lack of dopamine.

🔹 How antipsychotics impact dopamine.

Weekly Neuroscience Update

Credit: Nature Communications (2023). DOI: 10.1038/s41467-023-38248-4

Scientists have found that the gut microbiome holds Parkinson’s disease markers and may indicate a method of early diagnosis.

Deep sleep, also known as non-REM slow-wave sleep, may help reduce memory loss in older adults facing a heightened burden of Alzheimer’s disease. The research indicates that superior amounts of deep sleep can act as a protective factor against memory decline in those with existing high amounts of Alzheimer’s disease pathology, potentially helping to alleviate some of dementia’s most devastating outcomes.

Researchers have discovered new genetic risk factors for non-Alzheimer’s dementia, specifically Lewy body dementia (LBD) and frontotemporal dementia (FTD).

Scientists have made strides in uncovering the mechanisms underlying memory formation and consolidation in the brain during rest or sleep. A new study focuses on the role of the hippocampus, a brain region important for memory, and its place cells which “replay” neuronal sequences. The researchers built an artificial intelligence model to better understand these processes, discovering that sequences of experiences are prioritized during replay based on familiarity and rewards. The AI agent was found to learn spatial information more effectively when replaying these prioritized sequences, offering valuable insight into the way our brains learn and process information.

New research finds that the brains of otherwise healthy military personnel who are exposed to explosions show an abnormal brain accumulation of amyloid-beta protein—a protein that plays a role in the development of Alzheimer’s disease.

A new study has found that people with a genetic risk for psychosis have an imbalance of glutamate and GABA neurotransmitters in their brains, specifically in the hippocampus. This imbalance is associated with hippocampal atrophy, which may lead to the development of psychotic symptoms.

Researchers have developed human brain organoids that contain microglia, the immune cells of the brain. These organoids allow researchers to study how microglia develop and function in a more realistic setting than previous models.

Researchers used artificial intelligence to analyze speech in Parkinson’s disease patients, revealing distinct patterns. The AI found Parkinson’s patients used more verbs but fewer nouns and fillers in their speech, even before cognitive decline typically associated with PD was evident.

A research team has found that the risk of long COVID and its symptoms present very differently across diverse populations.

A new study sheds light on the potential role of diet in preventing dementia. The analysis explored the relationship between gut health and Alzheimer’s disease, uncovering a strong link between specific types of gut bacteria and the likelihood of developing dementia. The findings highlight the significance of gut microbiota in brain health and provide insights into the underlying mechanisms of Alzheimer’s disease.

Finally this week, researchers have created a revolutionary device that emulates the human eye’s ability to see colour.