Characteristics of cognitive function in patients with higher brain dysfunction after brain injury: an event-related potential study

The object of the present study was to compare the effects of facial affective stimuli on visual event-related potentials (ERPs) in patients with higher brain dysfunction after brain injury and healthy controls, using photographs of babies depicting sadness (a crying face) and pleasure (a smiling face). The P300 amplitude when viewing a smiling baby was smaller than that when viewing a crying baby for healthy controls. However, the P300 amplitude was the same when viewing a smiling baby as when viewing a crying baby for the brain injury patients. The P300 latency in patients when viewing a smiling baby as well as when viewing a crying baby was obviously and significantly longer than those in healthy controls. The P300 latency was significantly and positively correlated with the dysfunction scale of working abilities and social active abilities. These results indicated that these patients were likely to have cognitive dysfunction and that ERPs are a useful biological marker for the evaluation of such patients. These differences may reflect differences in information processing resulting from emotional influences caused by visual affective stimuli.