Temporal characteristics of the surprise reaction induced by schema-discrepant visual and auditory events

Abstract

Abstract Two experiments investigated the effects of a schema-discrepant event on the surprise reaction. Schema-discrepancy concerned a physical feature of irrelevant distractor words that were presented while the subjects performed a choice reaction time task. The stimulus onset asynchrony (SOA) between the distractors and the task-relevant stimuli was manipulated in both experiments. The occurrence of the schema-discrepant event led to subjective feelings of surprise and enhanced recall of the stimulus material. In Experiment 1, the presentation of a schema-discrepant auditory event resulted in a pronounced increase of reaction time (RT) with a 0.2sec SOA but not with a 1.5sec SOA. In Experiment 2, the effects of both fixed and variable SOAs of four different lengths (simultaneous onset, 0.5sec, 1sec, or 2sec SOA) were investigated within a visual task context. The increase of RT was found to be most pronounced with SOAs of 0.5sec and lsec respectively, and more pronounced with variable than with fixed SOAs, especially with a simultaneous onset. These results provide information about the temporal characteristics of the inhibitory component of the surprise reaction, and suggest that the inhibitory effects of surprise depend considerably on the subjects' state of preparation for the experimental task.