Category: Brain Research

Treatment expectation will boost or reduce drug efficacy

If you read my post yesterday on the neuroscience of success, you will have read of the unbeatable combination of optimism tempered with reality. Having written that post, it was fascinating today to read a paper in the current edition of Science Translational Medicine, which shows that a patient’s belief that a drug will not work can indeed become a self-fulfilling prophecy.

Researchers from Oxford University identified the regions of the brain which are affected in an experiment where they applied heat to the legs of 22 patients, who were asked to report the level of pain on a scale of one to 100. The patients were also attached to an intravenous drip so drugs could be administered secretly.

The initial average pain rating was 66. Patients were then given a potent painkiller, remifentanil, without their knowledge and the pain score went down to 55.

They were then told they were being given a painkiller and the score went down to 39.

Then, without changing the dose, the patients were then told the painkiller had been withdrawn and to expect pain, and the score went up to 64.

So even though the patients were being given remifentanil, they were reporting the same level of pain as when they were getting no drugs at all.

Brain scans during the experiment also showed which regions of the brain were affected. The expectation of positive treatment was associated with activity in the cingulo-frontal and subcortical brain areas while the negative expectation led to increased activity in the hippocampus and the medial frontal cortex.

The limbic system comprises several cortical and subcortical brain areas that are interconnected. This system essentially controls emotions, and the autonomic and endocrine responses associated with emotions. The hippocampus also belongs to the limbic system and plays an important role in long-term memory. Activity in the medial frontal cortex predicts learning from errors.

This latest research could have important consequences for patient care and for testing new drugs. Negative expectations about a drug can reduce its efficacy quite significantly, as indeed positive expectation can boost its efficacy. So it seems, that once more, a positive attitude holds the key to another area of success!

Weekly Round-Up

 

fightclub

Does a part of our brain host its own fight club?

In this week’s round-up of the latest discoveries and research in the field of neuroscience – the science of falling in love, the brain’s own fight club and how blogging may hold the secret of making boys write properly.

Continuing with the Valentine’s theme this week, Judy Foreman examines the scientific basis of falling in love.

In the Feb. 10 online issue of Current Biology, a Johns Hopkins team led by neuroscientists Ed Connor and Kechen Zhang describes what appears to be the next step in understanding how the brain compresses visual information down to the essentials.

In Itching for a Fight Science News carries the story that a small part of our brain hosts its very own fight club.

And finally, a report in The Independent newspaper on how blogging may have solved one of the most pressing problems that has perplexed the education world for years: how to get boys to write properly.

Chinks in the brain circuitry reveal our worry spots

Some people are more prone to anxiety than others

Open any newspaper, switch on any talk show on the radio this weekend, and you will be spoilt for choice with anxiety-inducing stories.

Living in this time of global recession, rising mortgage rates, political instability, it almost appears as if the media encourages us to be anxious on a daily basis. 

Easy as it is to respond with anxiety to these stories, it is in fact the least productive response to have in life. It is like a mental pain we inflict on ourselves, clouding our judgment and reasoning, zapping us of the energy we need to move forward with our lives and make sound decisions. Anxious thoughts activate stress hormones that trigger the brain’s  fight or flight response. But this arousal is temporary, and when it abates, is followed by exhaustion, apathy and even depression.

Not everyone is affected to the same degree by this tendency to react to life’s events with anxiety. We all know people who fret at the slightest thing, while others have the ability to remain calm and composed in the face of crisis. At its most chronic this tendency can lead to panic-attacks, social phobias, obsessive-compulsive behavior and post-traumatic stress disorder.

Now scientists at the University of California, Berkeley have discovered a neural explanation for why some individuals are indeed more anxiety-prone than others. Their findings, published in Neuron, reveal that chinks in our brain circuitry could be the answer, and may pave the way for more targeted treatment of chronic fear and anxiety disorders.

In the brain imaging study, the researchers discovered two distinct neural pathways that play a role in whether we develop and overcome fears. The first involves an overactive amygdala, which is home to the brain’s primal fight-or-flight reflex and plays a role in developing specific phobias.

The second involves activity in the ventral prefrontal cortex, a neural region that helps us to overcome our fears and worries. Some participants were able to mobilize their ventral prefrontal cortex to reduce their fear responses even while negative events were still occurring, the study found.

“This finding is important because it suggests some people may be able to use this ventral frontal part of the brain to regulate their fear responses – even in situations where stressful or dangerous events are ongoing”, said UC Berkeley psychologist Sonia Bishop, lead author of the paper.

“If we can train those individuals who are not naturally good at this to be able to do this, we may be able to help chronically anxious individuals as well as those who live in situations where they are exposed to dangerous or stressful situations over a long time frame,” Bishop added.

Bishop and her team used functional Magnetic Resonance Imaging (fMRI) to examine the brains of 23 healthy adults. As their brains were scanned, participants viewed various scenarios in which a virtual figure was seen in a computerized room. In one room, the figure would place his hands over his ears before a loud scream was sounded. But in another room, the gesture did not predict when the scream would occur. This placed volunteers in a sustained state of anticipation.

Participants who showed overactivity in the amygdala developed much stronger fear responses to gestures that predicted screams. A second entirely separate risk factor turned out to be failure to activate the ventral prefrontal cortex. Researchers found that participants who were able to activate this region were much more capable of decreasing their fear responses, even before the screams stopped.

The discovery that there is not one, but two routes in the brain circuitry that lead to heightened fear or anxiety is a key finding, the researchers said, and it offers hope for new targeted treatment approaches.

“Some individuals with anxiety disorders are helped more by cognitive therapies, while others are helped more by drug treatments,” Bishop said. “If we know which of these neural vulnerabilities a patient has, we may be able to predict what treatment is most likely to be of help.”

Source: University of California, Berkeley

Weekly Round-Up

 

Why do we love to learn about the brain?

In today’s weekly round-up..how patients with signs of dementia may improve their brain health with exercise, how brain cooling could aid stroke recovery, how brain scans can predict the likely success of giving up smoking, and finally why learning about the brain can become addictive. 

 According to researchers, just 40 minutes of moderate exercise in pensioners physically grows the brain and helps people enhance their brain power. It was found that regular exercise programs work on people already showing signs of dementia and loss of brain function. Meanwhile, McGill’s Dr Véronique Bohbot, believes that spatial strategies can reduce risk of dementia.

Cooling the brain of patients who have suffered a stroke could dramatically improve their recovery, according to research at the Centre for Clinical Brain Sciences at the University of Edinburgh.

Were you one of the many who made a New Year’s Resolution to give up smoking?  Brain scans showing neural reactions to pro-health messages can predict if you’ll keep that resolution to quit smoking more accurately than you yourself can. That’s according to a new study forthcoming in Health Psychology.

Finally, in the Psychology Today blog, Dr David Rock asks the question “why is it so engaging, almost addictive, to learn about how your brain functions” and concludes that it is “because it makes life feel richer, and enables us to achieve our intentions”.

What better way to end this week’s round-up! May the learning continue…

Weekly Round-Up

Does sleep help you learn? (Image: Big Stock)

In today’s weekly round-up..how memories take better hold during sleep, nature vs nurture, fake it til you make it, the nature of heroism, the pathology of Alzheimer’s, the neuroscience of fear and loathing, and more.

It appears from the latest research that the best way to hold onto a  newly learned poem, card trick or algebra equation may be to take a quick nap, for the brain is better during sleep than during wakefulness at resisting attempts to scramble or corrupt a recent memory. The study, published in Nature Neuroscience, provides new insights into the complex process by which we store and retrieve deliberately acquired information.

Athena Stalk in Your Brain and The Power of Rehearsing Your Future explains that the advice to “fake it til you make it” is backed up by some of the latest findings on the brain.

Interesting article from Jonah Lehrer in the Wall Street Journal on the perennial nature vs nurture debate. And in a similar vein,  is there a gene for heroism or is it down to social or economic factors?  Can neuroscience explain the nature of heroism?

The Neuroscience of Fear and Loathing is an interesting look at this universal emotion. 

Findings from a new study from the University of Haifa shows that people diagnosed as psychopathic have difficulty showing empathy, just like patients who have suffered frontal head injury.

Article in this week’s New York Times on a new brain scan tech­nol­ogy to detect Alzheimer’s pathol­ogy in the brain.

How Perception Reveals Brain Differences explores the ways in which brains differ from one another and the ways in which we owners perceive the world accordingly.

Stroke recovery boosted by Prozac

Stroke is the third biggest killer disease in Ireland – over 2,000 people die per year – causing more deaths than breast cancer, prostate cancer and bowel cancer combined. Up to 10,000 people will suffer a stroke in Ireland this year and one in five people will have a stroke at some time in their life.

An unexpected new finding for antidepressant drugs and a very important one.

Findings from the largest study of selective serotonin re-uptake inhibitors (SSRIs) and stroke report that giving stroke patients the antidepressant drug Prozac soon after the event helps their recovery from paralysis. A total of 118 French patients were involved in the study. The beneficial effects of the drug – more improvement in movement and greater independence – were seen after three months – helping patients gain independence. This finding suggests that this already licensed drug – also known as fluoxetine – could have a dual benefit in the treatment of acute ischemic stroke – that’s where blood flow and oxygen supply to the brain are impaired.

Antidepressant drugs can help neurons to grow

One theory about how antidepressants may help brains recover more quickly from stroke is that they encourage neurogenesis – the creation of new neurons – in particular in the hippocampus – a brain region implicated in emotion especially anxiety – an emotion which can wear down even the most resilient person.

The ability of antidepressant drugs to increase neuron growth and connections – brain plasticity – is a promising pathway for treatment of patients with ischemic stroke and moderate to severe motor deficit. It’s a controversial theory and so far it only appears to hold true in young mice. In middle-aged and older mice, no such neurogenesis was observed – so there may be another mechanisms operating. 

One thing is for sure – it’s an important finding and I hope we’ll see more work on this.

Weekly Round-Up

Do you gesture while you talk? These gestures seem to be important to how we think. They provide a visual clue to our thoughts and, a new theory suggests, may even change our thoughts by grounding them in action.

In  how the brain shops, we have an exploration of the neurons associated with valuing objects, and on a related theme,  A.K. Pradeep’s  Marketing to Women examines how women shop using their instinct.

An interesting study from Dehaene et al. on how reading rewires the brain 

Latest research shows that emotional stress can change brain function. A single exposure to acute stress affected information processing in the cerebellum — the area of the brain responsible for motor control and movement coordination and also involved in learning and memory formation.

Neuroscientists at MIT’s Picower Institute of Learning and Memory have uncovered why relatively minor details of an episode are sometimes inexplicably linked to long-term memories.

Finally, are you feeling a little bored? Well new research suggests that it is not just in your head. Individual differences in sensitivity to reward, for example, are another important factor.

The neuroscience of music

I am interested in ongoing research focusing on the effects of music training on the nervous system, and have given some talks on the subject over the past few years. It is also very interesting to note from recent studies that music training has implications for neuroeducation.

Research from Northwestern’s Auditory Neuroscience Laboratory strongly suggests that an active engagement with musical sounds not only enhances neuroplasticity, but also enables the nervous system to provide the stable scaffolding of meaningful patterns so important to learning.

According to Northwestern’s Professor Nina Kraus, director of  Northwestern’s Auditory Neuroscience Laboratory “The brain is unable to process all of the available sensory information from second to second, and thus must selectively enhance what is relevant,” Kraus said. Playing an instrument primes the brain to choose what is relevant in a complex process that may involve reading or remembering a score, timing issues and coordination with other musicians.”

Again, I am most interested to note that in Northwestern’s research shows that children who are musically trained have a better vocabulary and reading ability than children who did not receive music training.

Furthermore Professor Kraus says that “Music training seems to strengthen the same neural processes that often are deficient in individuals with developmental dyslexia or who have difficulty hearing speech in noise.”

Professor Kraus argues for proper investment of resources in music training in schools: “The effect of music training suggests that, akin to physical exercise and its impact on body fitness, music is a resource that tones the brain for auditory fitness and thus requires society to re-examine the role of music in shaping individual development. ”

“Music training for the development of auditory skills,” by Nina Kraus and Bharath Chandrasekaran, will be published July 20 in the journal Nature Reviews Neuroscience.

Weekly Round-Up

 

Eternal Sunshine Of the Spotless Mind

Would you take a pill to erase bad memories?

 

New Year is traditionally a time for many people to make a resolution to give up smoking. The smoking cessation medications bupropion and varenicline may both be associated with changes in the way the brain reacts to smoking cues, making it easier for patients to resist cravings, according to two reports posted online that will appear in the May print issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

If you are a parent of a teen going through puberty you will know all about the hormonal changes they go through.  Now, a Georgia State University scientist has found that those hormones in males may be key to changes in a part of the brain responsible for social behaviors.

It will take some time for those teen brains to develop fully though, as we know now from new research that the brain continues to develop after childhood and puberty, and is not fully developed until people are well into their 30s and 40s. The findings contradict current theories that the brain matures much earlier.

And still on the subject of teenagers, PBS science correspondent, Miles O’Brien looks at what could be happening to teenage brains as they develop in a rapid-fire world of technology and gadgets.

Finally, if you have ever watched the 2004 movie Eternal Sunshine of the Spotless Mind, you will have seen the fictional characters played by Jim Carrey and Kate Winslet use a technique to erase memories of each other when their relationship turns sour. It will have seemed an unreal expectation that we could erase memories so easily, but new research on “erasing” traumatic memories is quickly moving from the realm of science fiction to scientifically backed reality.

Introducing a new feature today – a weekly round-up of the best of the neuroscience news and views and latest research which has caught my attention.

How to use your brain to win friends and influence people

You are probably familiar with the  lyrics of James Taylor’s “You’ve got a friend” and indeed “ain’t it good to know you’ve got a friend when nothing’s going your way.”

But did you know that you have a friend you can call on who is with you all the time?

Say hello to your amydgala – your very own social satnav and your faithful friend.

So what is this amygdala and what role does it play in forming friendships and widening your social network?

Your amydgala 

Deep down in our reptilian brain lies a small thumbnail-sized structure with a name derived from the Greek word for almond. The amygdala has long been linked with a person’s mental and emotional state – in particular an emotional response – often an instant reaction – to something presently happening such as a perceived threat including the behaviours of escape and avoidance.

The bull who would not charge

As far back as the 1950’s a Spanish neuroscientist called Delgado used a tiny radio frequency stimulator implanted into the amygdala – the activation of which produced a variety of effects, including pleasant sensations. Delgado’s most famous experiment occurred at a Cordoba bull breeding ranch where he stepped into the ring with a bull which had a stimulator already implanted in the amygdala. The bull charged Delgado, who then pressed a remote control button which caused the bull to lose its aggressive instinct and to stop its charge. The bull incident was widely mentioned in the popular media at the time.

The amygdala alerts you to danger

In another important study – when brain images were recorded while persons were shown emotionally upsetting films, such as plane crashes or killer whales dismembering and eating baby seals and increase in the activity of the amygdala was observed suggesting that it is involved in storing memories for emotional events. Over the past 10 years neuroscientists have discovered that for it small size the amygdala is very complex with connections to and from many other brain regions and plays a protective role primarily involved in protection, moving us away from potentially dangerous situations.   

You’ve got a friend in your amygdala

In a social situation the amygdala processes reactions to violations concerning personal space. These reactions are absent in persons in whom the amygdala is damaged. Furthermore, the amygdala is found to be activated in when people observe that others are physically close to them, such as when a person being brain scanned knows that an experimenter is standing immediately next to the scanner, versus standing at a distance.

Behold the next big thing in social networking…the amygdala!

In interesting research published recently in the Journal, Nature Neuroscience  it has been shown that the size of your amygdala correlates with the size of your social network – taking the role of the amygdala in social interaction to another level. As a social species a larger amygdala gives us more options to manage our complex social lives – helping us to get along while getting ahead.

Thus jobs involving meeting people such as shopkeepers – who may interact with hundreds people including customers, suppliers and employes in an average day – will develop a larger and more intricately wired amygdala than say someone in solitary confinement.

All this points back to a fundamental finding in neuroscience – your brain is plastic.  So the message is simple – you need to meet as many people as possible if you want a rich and varied social life. You may not get along with everyone but as you learn and persist your amygdala will become your very own on-board social satnav.