Surprise, Surprise: This is a thesis on Surprise, Prediction, and the Oddball Effect

Currently there is contention in the literature as to what causes an unexpected stimulus, or oddball, to appear longer in duration than other repeated stimuli in the sequence. There have been two hypotheses proposed in regards to this; the extended oddball hypothesis, and the diminished standard stimuli hypothesis. The extended oddball hypothesis suggests that the oddball itself is perceived as having an extended duration, while the diminished standard stimuli hypothesis suggests that the effect is due to repetition suppression of the repeated standard stimuli. It was found in Experiment 1 and 2 that even when controlling for the recency effect, participants estimated the oddball stimulus as being exaggerated, as opposed to the standard stimuli appearing to have a shorter duration. This was supported in Experiment 3, which found that there was no significant difference between repeated and random conditions, and that the oddball was again judged to be significantly longer than both these conditions. The overall findings of this study strongly support the extended oddball hypothesis, using subjective measures of individual perception