Habituation and recovery of a slow negative wave of the event-related brain potential

Abstract

This study is concerned with the question of whether the late, slow negative wave 2 (SNW2) component of the event-related brain potential is a component of the orienting response (OR). As habituation of the SNW2 would be an argument for such a link with the OR, it was investigated using a variant of the classical repetition/change paradigm. Results supported major claims to be made for a component of the OR: the amplitude of the vertex SNW2 exhibited roughly the typical exponential decline with repeated stimulations (six numeric verbal stimuli presented seriatim in an ascending order) and responded incrementally to a change, at least in a narrow time slot, i.e. it exhibited partial recovery to an out-of-sequence stimulus. These findings were accompanied by similar effects on an exemplary OR component, the skin conductance response, and on such possible components of the OR as heart rate deceleration and the vertex P3 of the event-related brain potential. In so far as OR components should behave in comparable fashion in response to orienting stimuli, it is thus reasonable to suppose that the SNW2 relates to the OR.