Fighter pilots’ brains are “wired” differently suggests new research from the UK that used cognitive tests and MRI scans to show there are significant differences in the white matter connections between brain regions of fighter pilots compared to a group of healthy volunteers with no flying experience.

The researchers said they don’t know if the pilots were born with differently wired brains or if their brain wiring changed as they learned their expertise.

The study was the work of senior author Dr Masud Husain, a professor at the Institutes of Neurology and Cognitive Neuroscience at University College London (UCL), and colleagues from UCL and the University of Cambridge, and they wrote about it in the 15 Decmber issue of the Journal of Neuroscience.

For the study, Husain and colleagues compared the cognitive performance of 11 fighter pilots to a group of healthy controls with similar IQ but no experience of flying aircraft. They also took MRI scans of their brains.

Husain told the press they were interested in pilots because they often have to perform at the limits of human cognitive capability, “they are an expert group making precision choices at high speed”, often in the presence of conflicting clues.

The front-line Royal Air Force (RAF) Tornado fighter pilots and the controls completed two cognitive exercises: the “Eriksen Flanker” and “change of plan tasks” to assess the effect of distracting information on speed and accuracy of decisions, and ability to update a response plan in the presence of conflicting visual cues.

In the Flanker test they had to press a right or left arrow key depending on the direction of an arrow on a screen in front of them. The arrow was surrounded by other distracting arrows pointing in different directions.

In the change of plan test they had to respond quickly to a “go” signal, unless instructed to change their plan before making a response.

On the Flanker test, the pilots performed at the same speed but with greater accuracy than their age-matched controls. The pilots demonstrated superior cognitive control, “indexed by accuracy and postconflict adaptation”, and also showed “increased sensitivity to irrelevant, distracting choices”, wrote the authors.

On the second test, the pilots’ ability to “inhibit a current action plan in favor of an alternative response” was no better than that of the controls.

These results led the researchers to suggest that expertise in cognitive control may be more attuned to specific tasks and not generally better overall.

The researchers took brain scans of the participants using a type of MRI called diffusion tensor imaging (DTI) to look at the circuitry connections in the white matter of the brain.

DTI works by sensing how easy it is for water to diffuse along the axons in the microstructure of the brain. This measure is referred to as “white matter diffusivity”.

The DTI scans showed differences in white matter radial diffusivity of the pilots compared to the controls. The differences were “not only in the right dorsomedial frontal region but also in the right parietal lobe”, wrote the researchers.

Also, when they analyzed individual differences in reaction time costs in the conflict trials part of the Flanker task, they found “significant correlations with radial diffusivity at these locations, but in different directions”, whereas “Postconflict adaptation effects, however, were confined to the dorsomedial frontal locus”.

Husain and colleagues said their findings show that when exercising cognitive control human experts have an enhanced ability to tune into relevant and irrelevant signals, and this is accompanied by structural changes in certain parts of their brain: the white matter of their frontal and parietal lobes, to be precise.

“Our findings show that optimal cognitive control may surprisingly be mediated by enhanced responses to both relevant and irrelevant stimuli, and that such control is accompanied by structural alterations in the brain,” he told the press.

This suggests the differences between fighter pilots and the rest of us is their brains are wired differently in those areas that matter.

It’s not just a case of experts’ brain being larger, but as Husain explained, “the connections between key areas are different”.

“Whether people are born with these differences or develop them is currently not known,” he added.

Grants from the Wellcome Trust, the Medical Research Council and the NIHR Specialist Biomedical Centre at UCL/UCLH helped pay for the study.

“Expert Cognitive Control and Individual Differences Associated with Frontal and Parietal White Matter Microstructure.”
R. Edward Roberts, Elaine J. Anderson, and Masud Husain.
J. Neurosci., Dec 2010; 30: 17063 – 17067.

Additional source: UCL press release.

Written by: Catharine Paddock, PhD