Effect of attention modification by television viewing on somatosensory evoked responses and recovery functions.

Abstract

Recovery functions of somatosensory evoked responses have consistently provided measures discriminating between psychiatric patients and nonpatients. The present study was conducted to obtain data bearing on the possibility that patient-nonpatient differences may be attributable to group differences in state of attention. The specific aims were: 1) to determine whether consistent changes in somatosensory responses and their recovery functions accompanied the differences in attentiveness, compared with “resting” conditions, associated with television (TV) watching, and 2) to determine whether alterations in somatosensory evoked response characteristics would be correlated with electroencephalographic (EEG) changes taking place between rest and TV conditions. Somatosensory recovery functions, involving five interstimulus intervals, were measured under rest and TV conditions in 18 subjects. The integrated amplitude of the concurrent EEG was also measured. The results indicated that, although EEG amplitude was significantly reduced during TV viewing, there were no consistent changes in evoked response or recovery function measurements. Also, evoked response variations were not correlated with changes in EEG amplitude. The findings make it less probable that previously found patient-control differences in somatosensory recovery functions resulted from differences in general state of attentiveness. They also indicate that marked intraindividual changes in EEG amplitude may take place without correlated shifts in somatosensory evoked response measurements.