The influence of information on habituation of the "Wiener" filtered visual even related potential and the skin conductance reaction.

In this study the influence of the information value of visual stimuli on habituation in event related potentials (ERPs) at Fz, Cz and Oz locations and the skin conductance reaction (SCR) was investigated. An improved 'Wiener' filter was used to reduce the number of stimulus presentations. This enabled us to study P300 and SCR decrement in the same period of time. SCRs and Wiener filtered ERPs were determined over six stimulus presentations. Half of the 26 subjects received for 36 times a stimulus with a high information value in terms of complexity and the other half of the subjects 36 stimuli with a low information value. The results of this study show that decrement of the P300 amplitude occurs in about the same period of time as the SCR magnitude decrement. P300 habituation was manifested only in the fronto-central leads, the occipital P300 did not show habituation. A second difference in the topography of the P300 was that the effect of stimulus information was only found in the fronto-central leads and not in the occipital lead. As earlier studies, we did not find an effect of information on SCR habituation. The results show that the fronto-central P300 showed two important characteristics of the orienting response (OR). They are that habituation occurs in about the same period of time as in which a classical OR index as the SCR habituates and P300 amplitudes are larger when the information value of the stimuli is higher.