Does combat stress have a long-term effect on attention and memory?

How High-Throughput Compute is helping to understand the effects of combat on soldiers’ brains.

Veterans returning from active duty endure many challenges to readapt to a civilian life. For some, there is the added complication of combat stress, which affects their memory, attention span and other cognitive functions. But how? And for how long?

Neuroscientist Guido van Wingen and colleagues at the Academic Medical Centre in Amsterdam monitored a group of soldiers from before their first deployment to Afghanistan until 18 months after their return to civilian life. The idea was to look at how combat stress affects brain areas supporting cognitive functions such as memory and attention.

The team used the e-bioinfra science gateway to process and analyse 118 brain scans from 33 soldiers and 26 civilians used as controls. Thanks to a friendly user interface and the computing power of High-Throughput Compute, a workload of several weeks was condensed into two days.

From the psychological evaluation, the team found that combat stress interfered with the soldiers’ capacity for sustained attention shortly after their return from Afghanistan. The functional magnetic resonance (fMRI) scans of their brains during a memory test revealed that this effect was caused by functional changes in the midbrain. The analysis of the diffusion tensor (DTI) images showed that these were accompanied by structural alterations as well.

In the long run, the soldiers returned to their baseline value for attention, which means that the influence of stress on the midbrain’s function and structure is reversible.

The conclusions, published in the Proceedings of the National Academy of Sciences, show that combat stress impairs cognition by affecting the midbrain and its link with the prefrontal cortex and that this is largely reversible but could have an impact on future social and cognitive functions.

Troops deployed to the Kunar province, Afghanistan in September 2010. Photo by Staff Sgt. Gary A. Witte. Source: wikicommons

References

van Wingen et al. 2012 PNAS 109 (38):15508-15513. doi:10.1073/pnas.1206330109 (full text)

More information

Guido van Wingen’s research pages

The e-Bioscience group