Contingency awareness and its effects on fear-potentiated startle and extinction

Abstract

Fear-potentiated startle is defined as an increase in the magnitude of the startle reflex in the presence of a stimulus that has been paired with an aversive stimulus or event. It has been debated how much awareness of contingencies can affect fear-potentiated startle and the extinction of this. A conditional discrimination procedure was adapted to a human fear-potentiated startle paradigm in 33 healthy volunteers. This procedure allowed an assessment of startle responses at different lead intervals, as well as the participants awareness of contingencies in the study and the effect this had on the extinction phase. The participants achieved successful fear conditioning and fear-potentiated startle responses, but not satisfactory contingency awareness. There was significant extinction on the two longest lead intervals, but no extinction was found for the shortest lead interval.