Qualcomm Institute, University of California San Diego

MEG Working Memory N-Back Task Reveals Functional Deficits in Combat-Related Mild Traumatic Brain Injury

  • Cerebral Cortex
  • May 2019

Compared with healthy combat controls, mTBI participants showed increased MEG signals across frequency bands in frontal pole (FP), ventromedial prefrontal cortex, orbitofrontal cortex (OFC), and anterior dorsolateral prefrontal cortex (dlPFC), but decreased MEG signals in anterior cingulate cortex. Hyperactivations in FP, OFC, and anterior dlPFC were associated with slower reaction times. MEG activations in lateral FP also negatively correlated with performance on tests of letter sequencing, verbal fluency, and digit symbol coding. The profound hyperactivations from FP suggest that FP is particularly vulnerable to combat-related mTBI.

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Figure 4. MEG activations correlate with reaction time measures. Columns 1 and 2 in the left panel of show that MEG WM activations correlate with RT measure during 1-back task. Columns 3 and 4 in the left panel show the MEG-RT correlation result during 2-back task. Right panel: 3 representative scatter plots showing significant positive correlations between MEG activation and RT for mTBI (red stars) and control subjects (blue circles). The plots are for the 3 areas (a), (b), and (c) in which the locations are indicated by white arrows in the left panel.