Tuesday, 26 February 2013

Sports stars: a great example of brain-behaviour relationships

New research has found that athletes have a superior ability to rapidly process pictures, and to quickly learn unpredictable and dynamic visual information. This ability appears to give them the edge on the sporting field (or court..or arena).

In a study conducted by Jocelyn Faubert and colleagues from the University of Montreal, 102 professional athletes, 173 amateur athletes and 33 non-athletic students were asked to track and describe a series of abstract moving pictures on a screen. This was repeated 15 times over five days. The task was deliberately neutral and unrelated to sport, so that the results could not be assumed to be related to the athlete's greater familiarity with the tasks.

The professional athletes processed the visual information much faster than the other groups and improved their performance markedly over the five days. The other two groups started similarly, but the amateur athletes soon improved and had a much faster learning speed than the non-athletic students.

The results are a great addition to our understanding of the relationship between sporting prowess (behaviour) and cognition (brain), because previous studies have not found a significant relationship between sporting ability and performance on other cognitive tests.

This study revealed that "[Professional athletes] appear to be able to hyper-focus [on complex visual information] for short periods of time resulting in extraordinary learning functions," according to Jocelyn Faubert. The cognitive requirements for interpreting the visual information parallel situations such as driving, crossing the street and perfoming sport activities. Overall, they are smarter at learning how to interpret the "real world in action".

This coincides with previous research which showed differences between athletes and non-athletes in a part of the brain which regulates motion perception.

The study did not explore whether these abilities were innate or acquired through practice. This would be an interesting area for further research.

Thursday, 21 February 2013

The Neurobiology of Suicidality: development of a blood test?

A blood test to determine if a person is suicidal may sound like science-fiction, but if recent research in Australia is anything to go by, such a technology may be within reach of medical practitioners sooner than you think.

According to the Australian Bureau of Statistics, suicide is the most common cause of death for young Australians, aged between 15 and 40. Consequently, research in the early detection of suicidality is vital. While there are several observable behavioural warning signs of suicide, a growing number of studies have looked at the neurobiology of suicidality, in an attempt to determine reliable chemical warning signs. According to Dr. Guilemin from the University of New South Wales, most studies in the area have so far looked at the imbalances of a neurotransmitter called Serotonin in the brain. However, after decades of research the link between Serotonin and suicidal behaviour remains unclear.

More recently, another neurotransmitter in the brain, known as quinolinic acid, has come to the attention of researchers. In a study recently published in Neuropsychopharmacology, higher levels of quinolinic acid were found in individuals hospitalised after a suicide attempt compared to a healthy control group. Moreover, high levels of quinolinic acid were also related to higher scores on a self-report and assessor-report scale assessing suicide intent.

Importantly, the hospitalised patients in the study underwent a ‘washout period,’ where they did not receive any antipsychotic or antidepressant medication, which was argued to rule out the possibility that different levels of the neurotransmitter were due to differences in medication between the groups. Furthermore, the authors noted that quinolinic acid was high in all suicide attempt patients, regardless of whether they were given a diagnosis of depression or not. Consequently, this may suggest that higher levels of the neurotransmitter may be specifically linked to suicidality rather than more general depressive symptoms (Serotonin, on the other hand, is more reliably linked to depression). Interestingly, quinolinic acid in the suicide attempt group normalised to that of the control group six months later.

Previously, it has been suggested that abnormal activation of N-methyl-D-aspartate (NMDA) receptors in the brain may be in some way responsible for suicidal behaviour, consistent with the general findings that medications that blocks NMDA receptors appear to alleviate such symptoms. Quinolinic acid may therefore be an important part of this mechanism, given that this neurotransmitter is known to trigger and activate NMDA-Receptors.

Of course, even if an excess of quinolinic acid is found to be a reliable indicator of suicidality it does not necessarily make it in any way a direct cause, and future research is required to determine how effective medication that manipulates this neurotransmitter will be in reducing suicidality. As the authors of the study point out, suicidality is a complex phenomenon and such things as psychological factors may in fact be a more immediate cause, with the observed excess of quinolinic acid being a secondary trigger. Consequently, psychological therapies would continue to play a critical role in treatment.

Monday, 11 February 2013

How the brain organises our visual world

We live in a world in which we are bombarded with thousands of visual images every day. Recently researchers at the University of California provided a unique insight into how the brain organises and stores these visual images.

In the study, subjects watched hours of movies which included scenes from everyday life, whilst their brain activity was captured using functional magnetic resonance imaging (fMRI). They collected imaging data on 1,705 categories of objects (e.g. dog, building, road, furniture) and actions (e.g. jump, spin, hit, touch).

They then created a map to show how images of these objects and actions were organised by the brain. What they found was that the brain works efficiently to categorise images enabling similar images to be stored together in compact brain regions.

The graph below, taken from this study, shows how the brain links categories which are semantically related. To make it easier to identify, researchers have shown similar categories using the same colour. For instance, images to do with “person” are shown in green, whilst animal images can be seen clustered together in yellow. Images related to vehicles are identified by pink.

From this we can see how the brain links related categories together. Categories that are represented similarly in the brain are plotted at nearby positions. For example, information about humans shares the same neighbourhood in the brain as information about animals. Categories that have less in common, however, are located further away from each other in the brain. The graph below shows how to the brain, “person” and “talking” are represented as being more similar and having more in common than “kettle” and “talking”.

©University of Berkley

This study suggests that rather than each category being stored in its own distinct brain region, the brain is able to determine whether or not diverse categories share overlapping or common features and then group them accordingly in a continuous space. The brain actively ascertains the relationships between categories in order to work out where to store images. This more effectively utilises the relatively limited brain space available, given the size of our brains, and helps the brain to be more efficient by minimising the number of neurons required to represent each feature of an image.

A further interesting finding was that whilst only five subjects were included in the study, the authors were able to ascertain that different people share similar semantic layouts. That is, all of the subjects tended to use very similar cortical maps to store visual images. As well as providing us with a unique insight into brain organisation, the results of this study have implications for improving computer image recognition systems and creating other brain-machine interfaces.

Researchers have produced an interactive version of the brain map which provides a detailed insight into the visual function and organisation of the brain which can be found by following the link: http://gallantlab.org/semanticmovies/

Wednesday, 6 February 2013

A back to school blog - beware pen colour!

Teachers - beware pen colour! A recently published US study has found that the colour of the pen used by teachers when marking student's work has an impact on student-teacher relationships. The research, led by Professor Richard Dukes and Associate Professor Heather Albanesi from the University of Colorado involved 199 undergraduate university students who provided feedback on four versions of an essay (either low-quality or high-quality) which had marks and comments from a teacher in either red or aqua coloured pen. They were asked to provide feedback on:

  • Whether they agreed with the mark given
  • What mark they would give the paper
  • Various qualities of the teacher, including whether the teacher appeared to be knowledgeable, organised, nice, enthusiastic and had a good rapport with students

They found that while there were no differences between the perceptions of the quality of the work based on pen colour, perceptions of the teachers were higher for the essays marked in aqua compared to red. Professor Dukes reported that it the colour red is "loaded with emotion". It appeared the use of a red pen equates in the student's mind to "shouting" in the same way as writing in all capitals.

The main message of the research, according to Professor Dukes was that teachers should avoid using red pen if they want to convey constructive, critical comments to students. It "adds emotional loading" to the feedback, and if the teacher does not intend this negative emotion to be part of the communication, it would be worthwhile to rethink the pen colour.

"When the student ..performs well.. and receives a high grade, the situation is a "win-win" (teacher and student are feeling good about the process)," says Dukes. "However, when the student does not perform well, at least some of the blame is put upon the teacher."

This may also be related to the study of colour psychology, which claims that colours evoke emotions, can dramatically affect moods and are powerful communication tools. In the study of colour psychology, red has been found to evoke feelings of anger and hostility, while colours such as blue and green are soothing. There are also physiological responses related to the colour red, it increases the pulse and heart rate, and raises blood pressure and increases the appetite by increasing the metabolism.