EFFECTS OF EMOTION ON EVENT-RELATED POTENTIALS IN AN ARITHMETIC TASK

This study investigated the effects of conceptual and emotional anticipation on slow negative shifts in a S1-S2-S3 paradigm. S1 was an auditory warning signal; the task stimulus presented as S2 consisted of two digits on which subjects (n = 10) performed an arithmetic task. They had to match their solution with the probe stimulus presented as S3. Conceptual anticipation was manipulated by varying task difficulty; an easy and a difficult arithmetic task were compared. Emotional anticipation was manipulated by using auditory noise bursts. The controllability of this aversive event was varied by making this noise contingent on the subject's performance or not. A negative shift was only observed before S3 (the probe stimulus) and not in the S1-S2 interval. The amplitude of this negative shift was larger for the difficult than for the easy task. The Negative Slow Wave (NSW) that was elicited by S1 was largest, when the noise was non-contingent, whereas the SPN before S3 tended to be larger in the contingent condition. The results suggest that non-motor negative shifts are affected by emotional factors, but the direction of the effect seems to be related to the task demands.