Attention and Vigilance: Performance and Skin Conductance Response Changes

ABSTRACT The skin conductance response component of the orienting reflex was used to measure changes in attention during vigilance performance in order to test several hypotheses which have related aspects of vigilance performance to the occurrence and habituation of orienting or observing responses. Subjects detected irregularly presented visual signals among similar visual events during two 30‐min tasks. Skin conductance responses were analyzed in epochs of time immediately preceding and following signals and in nonsignal‐related time epochs. Magnitudes of skin conductance responses declined in both signal‐related epochs (pre and post), but this decrement was correlated with performance changes only in the post‐signal epoch. There was no decrement in SCR magnitudes during the nonsignal‐related epochs. Skin conductance response magnitudes were significantly larger both before and after detected signals compared to misses. The data support the hypothesis that changes in vigilance performance over time are related to habituation of the orienting reflex evoked by signals. They also suggest that attentional processes preceding signals are related to successful detections.