Source localization of an event-related potential marker of executive attention following mild traumatic brain injury

Recent research suggests that intact performance on an executive attention task after mild traumatic brain injury (mTBI) reflects functional adaptation within neural networks, rather than recovery of premorbid modes of information processing. However, it is unclear whether this compensation includes the recruitment of alternative neural processing resources. The current study used source localization analysis to determine the location and timing of activated brain areas involved in the generation of an eventrelated potential (ERP) component marker of executive attention in 10 adults with mTBI and in 10 matched healthy controls. In both groups the cerebral sources of the late processing negativity component of the ERP waveform elicited during the Paced Auditory Serial Addition Task were localized to the left ventrolateral prefrontal cortex and right dorsal anterior cingulate cortex. Timing of the dipole moments was consistent with previous reports of the relative contributions of subregions of the frontal cortex critically involved in aspects of executive attention control. Finally, whereas abnormal intensity of ERP activation has recently been related to the achievement of normal levels of performance after mTBI, abnormal sources of cerebral activation do not appear to be a feature of the compensatory response.