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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