Tag: neuroscience

Weekly Brain Research Update

Even for healthy people, stressful moments can take a toll on the brain, a new study from Yale University suggests.

Neuroscientists at the Johns Hopkins University School of Medicine have discovered how the sense of touch is wired in the skin and nervous system.

A new study of how the brain processes unexpected events found that neurons in two important structures handle both positive and negative surprises.

New research finds that brain activity increases during delusional thinking, a finding that may allow new interventions and retraining for people with the disorder.

A new UC Davis study shows how the brain reconfigures its connections to minimize distractions and take best advantage of our knowledge of situations.

Researchers from the Medical Research Council (MRC) in the UK have found a protein made by blood vessels in the brain that could be a good candidate for regenerative therapies that stimulate the brain to repair itself after injury or disease.

Drinking alcohol leads to the release of endorphins in areas of the brain that produce feelings of pleasure and reward, according to a study led by researchers at the Ernest Gallo Clinic and Research Center at the University of California, San Francisco

 

Weekly Round Up

Image Source: The Dana Foundation

Our senses of sight and hearing work closely together, perhaps more than people realize, a new UCLA psychology study shows.

A team of neurobiologists  has shown for the first time that cortex, the largest area of the brain that is typically associated with higher functions such as perception and cognition, is also a prominent site of emotional learning.

Tiny electric currents applied across regions of the brain can improve hand movements in recovering stroke patients for a short period, an Oxford University study has demonstrated.

For the first time, scientists have proven that cannabis harms the brain. But the same study challenges previously-held assumptions about use of the drug, showing that some brain irregularities predate drug use.

How might keeping patients awake during surgery lead to the more successful removal of brain tumours? James Keidel, in his shortlisted entry for the 2011 Wellcome Trust Science Writing Prize, explains.

Researchers from the University of Bristol have discovered that a chemical compound in the brain can weaken the synaptic connections between neurons in a region of the brain important for the formation of long-term memories. The findings, published in the Journal of Neuroscience, may also provide a potential explanation for the loss of memory associated with Alzheimer’s.

Inside the brain of a buddhist monk

Dr Josipovic has scanned the brains of more than 20 experienced meditators during the study

Since 2008, Dr Zoran Josipovic, a research scientist and adjunct professor at New York University, has been placing the minds and bodies of prominent Buddhist figures into a five-tonne (5,000kg) functional magnetic resonance imaging (fMRI) machine. He says he has been peering into the brains of monks while they meditate in an attempt to understand how their brains reorganise themselves during the exercise.

“Meditation research, particularly in the last 10 years or so, has shown to be very promising because it points to an ability of the brain to change and optimise in a way we didn’t know previously was possible.”

Dr Josipovic’s research is part of a larger effort better to understand what scientists have dubbed the default network in the brain. He says the brain appears to be organised into two networks: the extrinsic network and the intrinsic, or default, network.

The extrinsic portion of the brain becomes active when individuals are focused on external tasks, like playing sports or pouring a cup of coffee. The default network churns when people reflect on matters that involve themselves and their emotions. But the networks are rarely fully active at the same time. And like a seesaw, when one rises, the other one dips down. This neural set-up allows individuals to concentrate more easily on one task at any given time, without being consumed by distractions like daydreaming.

“What we’re trying to do is basically track the changes in the networks in the brain as the person shifts between these modes of attention,” Dr Josipovic says.

Dr Josipovic has found that some Buddhist monks and other experienced meditators have the ability to keep both neural networks active at the same time during meditation – that is to say, they have found a way to lift both sides of the seesaw simultaneously. And Dr Josipovic believes this ability to churn both the internal and external networks in the brain concurrently may lead the monks to experience a harmonious feeling of oneness with their environment.

Read more on this story at BBC Health

Why do we have brains?

Neuroscientist Daniel Wolpert starts from a surprising premise: the brain evolved, not to think or feel, but to control movement. In this entertaining, data-rich talk he gives us a glimpse into how the brain creates the grace and agility of human motion.

Opening a window into the movies in our minds

In research, that brings to mind the movie Minority Report, a group of neuroscientists have found a way to see through another person’s eyes.

By reconstructing YouTube videos from viewers’ brain activity, researchers from UC Berkeley, have, in the words of Professor Jack Gallant, opened ” a window into the movies in our minds.”

Gallant’s coauthors of the study,  published in Current Biology, watched YouTube videos inside a magnetic resonance imaging machine for several hours at a time. The team then used the brain imaging data to develop a computer model that matched features of the videos — like colors, shapes and movements — with patterns of brain activity. Subtle changes in blood flow to visual areas of the brain, measured by functional MRI, predicted what was on the screen at the time.

Lead author, Shinji Nishimoto, said the results of the study shed light on how the brain understands and processes visual experiences. The next line of research is to investigate if the technology could one day allow people who are paralyzed to control their environment by imagining sequences of movements.

 

 

 

 

 

Is the mind modular?

Mind – n. the human consciousness that originates in the brain and is manifested especially in thought, perception, emotion, will, memory, and imagination. 

Architecture of the human mind

No robot can solve a crossword, or engage in a conversation, with anything like the facility the average human being can. Somehow or other we humans are capable of performing complex cognitive tasks with minimal effort. Trying to understand how this could be is the central explanatory problem of the discipline known as cognitive psychology. There is an old but ongoing debate among cognitive psychologists concerning the architecture of the human mind. 

The ‘general-purpose problem-solver’ mind

According to one view the human mind is a’ general-purpose problem-solver’. This means that the mind contains a general set of problem-solving skills or ‘general intelligence’ which it applies to an infinitely large number of different tasks. So the same set of cognitive capacities is employed, whether you are trying to count marbles, deciding what movie to see, or learning a foreign language – these tasks represent different applications of the human’s general intelligence.

The modular mind

A rival view argues that the human mind contains a number of subsystems or modules – each of which is designed to perform a very limited number of tasks and cannot do anything else. This is known as the modularity of mind hypothesis. So for example it is widely believed that there is special module for learning a language – a view deriving from the linguist Noam Chomsky. Chomsky insisted that a child does not learn to speak by overhearing adult conversation and then using ‘general intelligence’ to figure out the rules of the language being spoken; rather there is a distinct neuronal circuit – a module – which specialises in language acquisition in every human child which operates automatically and whose sole function is to enable that child to learn a language, given appropriate prompting. The fact that even those with very low ‘general intelligence’ can often learn to speak perfectly well strengthens this view.

Clues from the broken brain

Some of the most compelling evidence for the modularity of mind hypothesis comes from studies of patients with brain damage. If the human mind were a general all-purpose problem-solver we would expect damage to the brain to affect all cognitive capacities more or less equally. But this is not what we find. On the contrary, brain damage often impairs some cognitive capacities but leaves other untouched. A good example of this is damage to a part of the brain known as Wernicke’s area – following injury or viral infection – which leaves a patient unable to understand speech although they are still able to produce fluent, grammatical sentences. This strongly suggests that there are separate modules for sentence production and comprehension. Other brain-damaged patients lose their long-term memory (amnesia) but their short-term memory and their ability to speak and understand are entirely unimpaired.

Modular or ‘general purpose problem-solver’ …or both?

The evidence for a modular mind is compelling and the philosopher Jerry Fodor published a book in 1983 titled The Modularity of Mind  which explained exactly what a module is. However the modular view is controversial and is not endorsed by all philosophers. Opponents argue that even in a general purpose problem-solver brain it is still possible that distinct cognitive capacities might be differently affected by brain damage. Fodor himself even admits that the answer may not be all that clear cut and suggests that while perception and language are modular, thinking and reasoning are almost certainly not – we solve some cognitive tasks using specialised modules and others using our ‘general intelligence’. However not all psychologists agree with this. 

Is the mind scientifically inexplicable?

Exactly how many modules there are and precisely what they do, are questions that cannot be answered given the current state of brain research. Most neuroscientists equate mind and brain as one and the same thing and predict that in the not-too-distant future neuroscience will deliver a radically different type of brain science, with radically different explanatory techniques what will explain the architecture of the human mind.