Alterations of the orienting reaction in patients with late posttraumatic mental disturbances

A polygraphic study performed on 115 patients with late posttraumatic mental disturbances has shown marked alterations of the orienting reaction. The alterations, estimated by testing for the electrographic components of the orienting reflex elicited by a repetitive auditory stimulus and for their habituation, were expressed by changes in the intensity, resistance to habituation, and sequence of habituation of the somatic, autonomic, and EEG components. The character and severity of these alterations depend on the clinical aspects of the mental disturbance, the lesional aspect of the craniocerebral trauma, the site of the traumatic impact, and the features of the EEG tracings.