22 September 2011

Not tonight darling

The clinical trials of the drug flibanserin were the first ever that tested a drug that works at the level of the brain to enhance libido in women reporting low sexual desire.

Professor of Obstetrics and Gynecology, School of Medicine, University of North Carolina, John Thorp McAllister comments that while flibanserin was a poor antidepressant, it appeared to increase libido in lab trials.

He conducted multiple clinical trials and the women in the studies who took it for low sex drive reported significant improvements in sexual desire and satisfactory sexual experiences. These subjects didn’t report any specific change in mood or depression

The drug is known to alter the level of serotonin in the brain and it shows promise as the first drug to treat female libido in this manner, rather than drugs which increase blood supply to the sex organs. More trials are required but I bet this will be a popular drug when it is able to be subscribed by doctors. And surely increased sex has a positive effect on depression?

Why chimps can't talk

Scientists have long since wondered why it is that humans developed the ability to express themselves through speech whereas other animals haven’t.  In the past, most research focused on the circumstances of human evolution, implying that speech developed as a result of the need for more advanced communication.  But more recently, scientists have begun to look at the generic makeup of humans to see if there is a more fundamental reason.

A recent article in the journal ‘Nature’ considered research being undertaken by the University of California where they are comparing a gene called ‘FOX2P’ to the same gene in chimpanzees, our nearest relative in the animal kingdom.

During their experiments they applied FOX2P genes from humans and chimps to cells in the laboratory to see which circuits they activated.  To their surprise, they found that the human and chimpanzee versions of the gene triggered different reactions.  Despite the crude similarities between chimpanzee and early human brains, it appears that the human version of the FOX2P gene ‘switches on’ the circuits in the brain that are associated with language and speech, the so called Broca and Wernicke regions, whereas the chimpanzee version didn’t.

The FOX2P gene had previously been known to be implicated in speech, as defects in the gene were known to cause speech and language impairment, but the extent of its involvement is a new discovery that paves the way for new avenues of research.  For example, by identifying the genes that are influenced by FOX2P it may be possible to develop cures for a variety of speech related problems and conditions.

The implication this research has for furthering our understanding of the development of the human brain, is that it appears language may have developed as a result of a genetic mutation, rather than as the result of environmental requirements and Darwinian evolution.

30 May 2011

Mother hen

British researchers at Bristol University, School of Veterinery Sciences have shown that hens show empathy to their young – the first time this has been shown in a bird.

Making use of technical advances in non-invasive monitoring, the researchers found that domestic hens show a clear physiological and behavioural response to their chicks’ distress.

During one of the controlled procedures, when the chicks were exposed to a puff of air, the hens’ heart rate increased and eye temperature decreased. The hens also changed their behaviour, and reacted with increased alertness, decreased preening and increased vocalisations directed to their chicks.

Empathy was once thought to be a completely human trait and that the brains of mammals functioned for survival and reproduction, not for any purpose of emotional intelligence. Of course this finding has implications for the welfare of chickens in battery farms and research labs.

It also supports the theory that in humans our empathetic ability resides in the 'lower' parts of the brain, areas such as the limbic system and brain stem, which we have in common with other mammals.

Switching off fear

Researchers at Stanford University have found that stimulating a particular brain circuit can counter fear. Pulses of light triggered the stimulation in mice and boosted their willingness to take risks. Inhibiting it had the opposite effect and made them more timid.

Neuroscientist Professor Ken Deisseroth targeted a circuit within the amygdala area of the limbic brain working within the specialist field of optogenetics, where nerve cells become photo-sensitive. The action of the cell can therefore be controlled and switched on or off by using different wavelengths of light.

The mice became much more comfortable in situations they would otherwise be wary of – such as being in wide open spaces. As soon as the light was pulsed into the brain circuit, the mice were much more willing to explore. Yet changing the pulse to a different wavelength turned the mice much more anxious.

This could be the beginning of some interesting debates around treating human anxiety and panic, which of course can be debilitating for many people.

I wonder if optogenetics is responsible for our behaviour in laser games and discos?!

Unable to recognise a face?

I was with a friend the other day and she looked at me for a long time before saying my name. I casually asked if all was OK and she told me she suffers from face-blindness – which I never knew about, even though I have known her for 10 years. She took her cue to realise it was me, when she remembered the dress I was wearing.

The condition is called prosopagnosia which can be inherited or caused by a brain injury. For my friend, its symptoms occurred quite suddenly as an adult and she had had no injury as a catalyst – she described it as being very frightening and only achieved some sense of relief with the diagnosis. It is more than not being able to put a name to a face, which is something a lot of people experience. It is caused by an impairment in the right hemisphere of the brain that specifically identifies faces. She can make out facial features fine – and is actually a wonderful portrait artist – but she doesn’t connect it with that person in her brain.

Dr Joseph DeGutis, a neuroscientist at Harvard University is currently using a training programme to help sufferers which encourages them to look at the whole face as typically they seem to look at only one facial feature at one time.

For my friend, having prosopagnosia has increased her sensory acuity in other senses. She says she is far more conscious of smell – the perfumes people wear, if they are big coffee drinkers for instance. And I was glad to offer her the genuine feedback that she comes across always as being a wonderful listener – which she would be irrespective of the prosopagnosia – as she is very aware of different people’s voices, the pitch, tone and different subtleties in the spoken word.

14 March 2011

My Brain Hurts

In the middle of a workshop last week, one of my participants announced that she needed a rest as her brain was full! I was aware that I had possibly overloaded the class with information, but was intrigued by her comment that her brain hurt and she all of a sudden felt utterly exhausted.

We are all familiar with the mid afternoon energy slumps and the consistently well documented advice around regulating blood sugar levels by eating little and often, with a good balance of nutrients, keeping hydrated, maintaining a regular sleep pattern to promote healthy rhythms etc etc. But what happens when we feel real brain “pain” and are utterly depleted?

Fatigue, like pain is fundamentally a brain mediated sensation. As with pain, most people report that they experience fatigue as an overwhelming phenomenon, apparently occurring mainly in the muscular skeletal areas. However on closer questioning, people also refer to mental fatigue and this is typically precipitated by complex neurological tasks or intense bouts of concentration. At the extreme end, some people may suffer from Chronic Fatigue Syndrome, which is still a subject of intense interest to neuroscientists – as it is as much about the brain, the nervous system as it is about the physical body.

Fortunately my participant came back from the mid-afternoon workshop break after a glass of water and a walk around the block, challenging the group for more information!  It's as though when we get to overload and we need a period of down-time to process the information and clear the 'log-jam' before coming back for more.

11 March 2011

Older drivers 'see too much'

In October 2009 we reported on research by Adam Gazzaley of the University of California in an item entitled “Does your brain slow down as you get older?” The researchers, who were looking into the speed at which older people perform mental tasks relative to their younger counterparts, found that the brains of older people were not slower but that they appear slower because older people’s brains are not as good at blocking irrelevant information. They therefore are more easily distracted and find it harder to concentrate on the task in hand.

I mention this as recent research by Professor Duje Tadin at the University of Rochester in New York has produced similar conclusions.

His research was investigating a worrying phenomenon of ageing that results in older drivers failing to notice other cars, pedestrians and cyclists moving around them. For some time this has been blamed on a reduced ability to notice moving objects, but the research suggests that it is actually caused by an inability to separate the objects from the background.

In healthy young brain a region called the middle temporal visual area actively suppresses irrelevant background motion so that the person can concentrate on the more important movements of smaller objects in the foreground. Previous studies have found that elderly people, as well as those with psychological conditions such as schizophrenia and depression are better at perceiving motion in the background.

The problem is that since our brains are only capable of consciously processing a limited amount of information at any one time, this heightened awareness of the background serves as a distraction that draws our attention away from the more important foreground objects.

"The amount of visual information around us is huge, and we don't have the brain power to process it all," Tadin said. "Evolutionarily speaking, moving objects are the most important visual features to detect quickly, because they could be your lunch or they could want to eat you for lunch. It just makes sense that our vision prioritizes processing them."

The results of both studies would therefore suggest that a natural part of the ageing process is an improvement in our ability to perceive things holistically, but decrease in our ability to concentrate on the specifics of any one thing.

While the implications of this research for the medical professions lie in improved diagnosis of certain medical conditions, the implication for employers is that to get the best from their staff they should consider these age-related differences when assigning tasks.

Risk and Reward

When a child is first born it is broadly speaking true to say that they know nothing.  While they enjoy the support and protection of their parents this is not a problem, but if they are to survive in the longer term, they need to learn fast, which is why we are all born with an innate sense of curiosity.

At this stage of life learning consists of experimenting, pushing boundaries, copying others and, above all, making mistakes.  Adults also play an important role in our learning by helping us differentiate between good behaviour and practices and bad ones.  For example, we quickly learn to recognise the meaning of the different sounds our mothers make when we on the one hand do something cute, or on the other use her favourite lipstick to draw on the wall.

As we grow bigger and more physically capable, this learning-by-doing approach brings increased risks, which is why parents will often keep toddlers on reins to stop them suddenly running into the road. 

At some stage though we need to be able to fend for ourselves, so we have to develop the ability to assess and judge a situation before acting.  This cognitive process takes place in the cerebral brain, which is the part of the brain that allows humans to over-ride our more basic animal instincts – to think before we act. Recent research at the University of Oregon has highlighted the ways in which the regions of the brain involved in making these reasoned judgements develop.  Their research study used fMRI (functional magnetic resonance imaging) scans of the brains of 24 girls and 12 boys when they were 10 years old and then again three years later when they were 13.

Their findings, which are detailed in the March 2011 edition of the journal Neuron, were that activity in an area of the prefrontal cortex increased significantly between the ages of 10 and 13.  So at just the time when parents are worrying that their children are coming under the influence of other people and being exposed to a broader range of risks, their brains are adapting to help them cope.

However, this raises the question as to why this region of the brain does not develop earlier, as I am sure that most parents would agree that even at 13 years children tend to take many more risks than they would like.  The most likely answer is that the inhibitions of youth are a key component in a child’s learning and that if they were restricted by a greater sense of risk aversion their learning would be impeded.  It is also likely that by developing this ability later in life and slowly over a period of time enables children to learn the skill of balancing risk and reward.

Possibly these research findings explain why some children switch from taking too many risks in their early childhood to being far too risk averse as teenagers.

11 January 2011

Disrupting harmful memories

Post-traumatic stress disorder (PTSD) is now recognised and accepted as a real medical condition that can affect anyone, but which is most prevalent in people whose jobs place them in situations where they are likely to witness horrifying events.

When such events occur, such as following the 7/7 London bombings or after a particularly harrowing Police raid, people are often given time off to get over the initial shock.  However, recent research findings from Oxford University suggest that this may not be the best thing to do.

As part of their research they showed 40 healthy volunteers a series of traumatic images of injuries sustained in motoring accidents.  After waiting for 30 minutes, half the volunteers played the computer game Tetris for 10 minutes while the other half did nothing.  The volunteers were then asked to record each occasion during the following week when they had "flashbacks" to the images.

The result was that the volunteers who had played Tetris experienced significantly fewer flashbacks, suggesting that their memory of the images was less strong.

Dr Emily Holmes, who led the research, concluded that the reason the Tetris player had fewer flashbacks was because concentrating on the game so soon after seeing the images disrupted the brain's ability to commit the images to long-term memory.  She explains that this is because, in forming memories, the brain must process the information in two ways; one sensory and the other analytical.   Given the brain's limited ability to do more than a few things at any one time, such as performing a numerical calculation while holding a conversation, the playing of the game therefore interfered with its ability to complete the process of committing the traumatic image information to memory.

Although this was only a small study, it does suggest that the best course of action for anyone who is unfortunate enough to find themselves in a situation where they are likely to experience PTSD is to get them busy with something else as soon as possible.

For everyone else the lesson to be learned is that "down time" is important to both memory and the processing of information.  So next time you leave one meeting and rush straight into the next, just remember that while being "back-to-back" may look impressive, it is in fact limiting your ability to process information and remember important facts.

ADHD and the Daydreaming Switch

Attention Deficit Hyperactivity Syndrome (ADHD) is a condition that appears to prevent people from concentrating on any one thing for more than a few moments at a time. It is most prevalent in children and often comes to light when they begin school.

For a long time the condition was considered to be psychological but now researchers at the University of Nottingham believe that they have found a physiological reason for the condition.

The research focused on the default mode network (DMN) that allows our brains to daydream when we are not focused on a particular task. This default setting in the brain is what enables us to relax and is also thought to be associated with the process of dreaming and in converting short-term memories into long-term memories. For example, it is this default process that allows ideas to “pop into your head” when you are thinking of nothing in particular.

In the case of children with ADHD the researchers found that they were not able to switch off the daydreaming default mode, and that this was therefore the reason why they found it far harder to concentrate.

Dr Martin Batty, co-author of the study, said: "Using brain imaging, we have been able to see inside the children's heads and observe what it is about ADHD that is stopping them concentrating."

"Most people are able to control their 'daydreaming' state and focus on the task at hand. This is not the case with children with ADHD. If a task is not sufficiently interesting, they cannot switch off their background brain activity and they are easily distracted. Making a task more interesting, or providing methylphenidate (otherwise known as Ritalin), turns down the volume and allows them to concentrate."

The findings are published in the Journal of Child Psychology and Psychiatry.

10 January 2011

Are politicians made or born?

According to British scientist, Professor Geraint Rees of University College London, the brains of Conservative politicians and supporters are physically different to those of their Labour counterparts.

Inspired by an off-hand comment from the actor Colin Firth, Professor Rees scanned the brains of a Conservative and Labour politician and issued a political questionnaire to 90 other people who had previously had their brains scanned by the UCL Institute of Cognitive Neuroscience.

What they found was that Conservatives have larger amygdalas, which are almond shaped areas in the centre of the brain often associated with anxiety and emotion, and smaller anterior cingulates, an area at the front of the brain associated with courage and looking on the bright side of life. The opposite was true in the brains of people with more liberal and left-leaning political opinions.

Since the study looked only at adult brains it is impossible to tell whether these peoples' brains had developed in this way as a result of their beliefs, or whether it was the physical attributes of their brains that led them to hold those views in the first place. All we know is that where nature and nurture are concerned, neuroscientists appear to be increasingly favouring nature over nurture – which suggests that politicians and political activist are not made, they’re born!

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