Combined behavioral and EEG power analysis in DAI improve accuracy in the assessment of sustained attention deficit.

In clinical routine, the evaluation of sustained attention is often performed by analyzing the behavioral data collected during specific tests. Such analyses are rarely accompanied by a detailed examination of the subject's simultaneous electroencephalographic (EEG) activity, and particularly its frequency content. In this study, a group of healthy volunteers and a group of patients affected by diffuse axonal injury (DAI) were tested while performing a modified version of the Conners' continuous performance test. A comparative study was carried out between the behavioral and neuropsychological data obtained during the task, to investigate neural activation. Spectral power was calculated for each of the recorded EEG signals, taking account of the frequency bands traditionally considered in literature. Then a compressed spectral array sequence of spectra was plotted to put into evidence the temporal modifications in the signal power spectral density, and, finally, the analysis of the rhythm variability was carried out. Evaluation of the results thus obtained shows that the two groups registered very different cerebral activation dynamics during the ongoing attentional task. Moreover, DAI patients showed mild cortical activation in the prefrontal region, spread equally throughout both brain hemispheres, while controls showed strong predominant activation of the right prefrontal area. Our findings encourage further investigations of the combined employment of tests and EEG recordings during the clinical assessment of sustained attention performance.