How does the brain multitask?

Dr Adam Gazzaly,  director of the Neuroscience Imaging Center at the University of California, San Francisco, answers the question of how the brain multitasks on the brainfacts.org website:

Multitasking is an attempt to engage in more than one goal at the same time. When two tasks demand competing attention, there is generally a switching that occurs between the neural processes involved, rather than concurrent processing as may be expected with true multitasking. Of note, recent research suggests that it may be possible for the brain to split two demanding tasks.

The prefrontal cortex has been frequently implicated as a brain region that mediates multitasking and the switching processes. Multitasking is commonly shown to impair cognitive performance, as each switch results in a reduction in performance compared to doing one task at a time. However, there is growing evidence that the ability to multitask can be trained with repetitive and adaptive practice. Multitasking abilities have been observed to decline as we age.

Your Weekly Neuroscience Update

Drinking three cups of coffee daily could help keep Alzheimer’s disease at bay, according to the results of a new study.

People who frequently use tanning beds experience changes in brain activity during their tanning sessions that mimic the patterns of drug addiction, new research shows.

A research team at Aalto University and Turku PET Centre has revealed how experiencing strong emotions synchronizes brain activity across individuals.

A new study has begun to unravel one long-observed enigma in major depressive disorder: why, for most patients, it continues to come back, even after it seems to have been cured or gone away on its own.

A recent placebo-controlled study showed evidence of trans-cranial bright light’s effect to brain functions when administered through the ear. Bright light stimulation was found to increase activity in brain areas related to processing of visual sensory information and tactile stimuli. The findings are the first ever published scientific article about functional modulation of the brain with bright light delivered to the brain through the ears. Researchers from the Max Planck Florida Institute (MPFI) and New York’s Columbia University have discovered that the rewiring involves fibers that provide primary input to the cerebral cortex, which is involved in cognition, sensory perception and motor control.

When people close their eyes, they can form mental images of things that exist only in their minds. Neuroscientists studying this phenomenon at medical schools in the Texas Medical Center believe that there may be a way to use these mental images to help some of the estimated 39 million people worldwide who are blind.

A Canadian doctor has found a promising way to detect concussions using a simple blood test that can tell within the first hour after a blow to the head how severe the injury may be.

Why my ultimate exam tip is an exam sip!

As the Junior and Leaving Certificate exams kick off today, I want to wish you all good luck and to remind you not to forget to bring a bottle of water with you into your exams!

It’s that time of the year again when the two big state exams – junior and leaving certificates kick off for a generation of Irish youths.  The leaving cert is the hardest exam I’ve ever had to sit  – throughout my years as a student in University, and afterwards working in a laboratory as a neuroscientist, nothing really compared to the intensity of that exam.  

Drink water to improve your grade!

Scientists from the University of East London report that bringing a bottle of water with you into your exam boosts your grade. Students who brought water with them did better in the exam than those without water.  The researchers accounted for the 447 undergraduate students’ prior grades, so it’s not just a matter of smarter students being more likely to bring a bottle of water into the exam.

Drinking water makes you smarter

Controlling for ability from previous coursework results, scientists found those who drank water during the exam scored an average of 5% higher than those who did without.

The ultimate exam tip – is an exam sip!

Scientists explain that there may be a few reasons for this link between bringing water (and presumably drinking it) and better grades:

  1. Previous studies have shown that a dehydration level of just 1% of your body weight reduces your thinking functions, so it makes sense that drinking water improves mental performance.
  2. The desire to drink water (thirst) is driven by a small protein (a peptide) called vasopressin in the brain. Vasopressin has also been implicated in making new memories and with the positive feelings associated with social behaviour thereby leading to a better performance by reducing anxiety in an exam situation,
  3. By offering a momentary distraction – taking a sip of water – drinking water may also break a chain of thoughts and free the mind to focus on the task at hand, leading to better performance – thereby reducing anxiety during the exam.
  4. Drinking water might also just activate a placebo affect – if you believe water boosts your brain power, that belief alone could improve your performance.

The research continues – either way, don’t forget that bottle of water on your next exam.

References 

Lim MM, Young LJ (2004). “Vasopressin-dependent neural circuits underlying pair bond formation in the monogamous prairie vole”. Neuroscience 125 (1): 35–45.

Know Your Neurons

selection-of-neuron-types

Different Types of Neurons A. Purkinje cell B. Granule cell C. Motor neuron D. Tripolar neuron E. Pyramidal Cell F. Chandelier cell G. Spindle neuron H. Stellate cell (Credit: Ferris Jabr; based on reconstructions and drawings by Cajal)

The Know Your Neurons series on the  Scientific American website features some great information on the discovery and naming of neurons, alongside some terrific historical images.

human-neurons-stained

Human hippocampus stained with Golgi’s method (Credit: Wikimedia Commons)

drawing-of-neurons

Cajal’s drawing of Purkinje cells and granule cells in a pigeon’s brain (Credit: Wikimedia Commons)

Learn more: click here

Neuroscience News Update

University of Georgia researchers have developed a map of the human brain that shows great promise as a new guide to the inner workings of the body’s most complex and critical organ.

Brains that maintain healthy nerve connections as we age help keep us sharp in later life, new research funded by the charity Age UK has found.

The brain reward systems of women with anorexia may work differently from those of women who are obese, a new study suggests.

Emotional stress caused by last year’s tsunami caused a part of some survivors’ brains to shrink, according to scientists in Japan who grasped a unique chance to study the neurological effects of trauma. On a quest to better understand post-traumatic stress disorder (PTSD), the researchers compared brain scans they had taken of 42 healthy adolescents in other studies in the two years before the killer wave, with new images taken three to four months thereafter. Among those with PTSD symptoms, they found a shrinking in the orbitofrontal cortex, a part of the brain involved in decision-making and the regulation of emotion, said a study published in the Nature journal Molecular Psychiatry.

Neuroscience News Update

Image Credit: Shutterstock

Harvard neuroscience researchers have just confirmed what many of us have suspected all along: social networks like Facebook, Twitter, Instagram and Pinterest are “brain candy” for Internet users. Every status update, every tweet, every pin is a micro-jolt delivered squarely to the pleasure centers of our brains.

Brain networks — areas of the brain that regularly work together — might avoid traffic jams at their busiest intersections by communicating on different frequencies, according to new research.

Researchers at Stanford University have determined from brain-imaging data whether experimental subjects are recalling events of the day, singing silently to themselves, performing mental arithmetic, or merely relaxing.

Recent research has revealed some of the changes that take place in women’s brains during motherhood, and experts say that it could help them figure out what motivates mothers to care for their babies.

A study recently published by a University of Colorado School of Medicine researcher shows that reward circuits in the brain are sensitized in anorexic women and desensitized in obese women. The findings also suggest that eating behavior is related to brain dopamine pathways involved in addictions.

Researchers at the University of Leeds have found a previously unknown mechanism through which pain is signalled by nerve cells – a discovery that could explain the current failings in the drug development process for painkillers and which may offer opportunities for a new approach.

Post-traumatic stress is estimated to afflict more than 300,000 veterans of Iraq and Afghanistan, but until now, it’s been labeled a “soft disorder” — one without an objective biological path to diagnosis. That may have changed this week, after researchers at the University of Minnesota and the Minneapolis VA Medical Center announced they’d found a distinct pattern of brain activity among PTSD sufferers.

A live tweeted brain surgery this week reached an online audience of more than 14 million people, according to the hospital that used social media to broadcast the operation.

High-impact activities like football are known to cause creeping brain damage that can’t easily be detected until after death. But promising research may give rise to new methods of diagnosing chronic traumatic encephalopathy.

Scientists have proven that light intensity influences our cognitive performance and how alert we feel.

Scientists at Weill Cornell Medical College have discovered that the single protein—alpha 2 delta—exerts a spigot-like function, controlling the volume of neurotransmitters and other chemicals that flow between the synapses of brain neurons. The study, published online in Nature, shows how brain cells talk to each other through these signals, relaying thoughts, feelings and action, and this powerful molecule plays a crucial role in regulating effective communication.

Why Is Yawning So Contagious?

Yawning: A reflex act of opening one’s mouth wide and inhaling deeply.  

Why do we yawn? Snakes do it, fish do it, even babies in the womb do it – but the truth is nobody really knows why.  However the emergence of the new discipline of neuroscience – the scientific study of the nervous system – is investigating why we humans yawn – and the answers might surprise you.

Time to yawn

It happens on hot days more than on cold, which leads to speculation that yawning cools the brain. On the other hand, someone running a fever yawns less than normal, while uncontrollable yawning maybe a symptom of diabetes or a stroke. Yawning often peaks just before bed-time but then, oddly enough, stops when we are lying down – still awake – in bed. Yawning is also common just after we get up – when, presumably, we are not tired at all.  

Theories abound

Different species do it for different reasons – birds may use it as a cooling mechanism while snakes appear to use it to readjust their detachable jaws after swallowing a large meal. In humans yawning is believed to have evolved as a social cue to signal to others – an expectation that something different or novel is about to happen – a kind of non-verbal way of saying ‘time for us all to go to bed’. This might explain the increase in yawning observed in parachutists about to jump and in negotiators – the moment talks take an unexpected turn.

Yawning is catching

But there is another unexpected twist to yawning. Like laughing and vomiting – yawning in humans is a contagious behaviour. Once we see someone else do it we are inclined to copy it.  Yawning is in fact by far the most contagious behaviour for us humans and such a spontaneous copying response to a second person’s signal of mood is an unmistakable sign of empathy; the ability to understand and to react to someone else’s state of mind. This might explain why people with autism or with schizophrenia find it hard to yawn – and they respond less to the yawns of others than do most of us.

Show you care – yawn back

Empathy is what makes us kind and people-friendly and the speed and extent with which a person yawns in response to your yawn may be a fast way of finding out if he or she is on your emotional wavelength – a kind of non-verbal way of saying ‘I feel you brother’.  In this way, yawns are most contagious within families but are less inclined to be copied by strangers. The captain of a football team might yawn in the dressing room before an important game and then watch to see who is ‘with him’.  

Mirror mirror on the wa…. yawn

The recent discovery of the so-called mirror neuron system in the brain which helps us to respond sympathetically and empathetically to others may help explain why yawning is associated with empathy, Mirror neurons help connect us emotionally to other people. They help us to respond sympathetically towards others and allow us to anticipate others intentions. When you watch a good movie with good actors then that’s why you feel the way you do. In this way, yawning may be a powerful non-verbal activator of the mirror neuron system in others – explaining why it is so contagious.

He who dares – yawns

Far from being bad manners, yawning is a sign of our deep humanity. So, go on give a giant yawn for mankind.