Abstract
When confronted with familiar tasks, people draw upon past experience to anticipate sensory input and optimize their performance. While it is uncontroversial that predictions influence perception, their effects on visual detection sensitivity are debatable; some studies suggest that surprise facilitates detection, whereas others show the opposite effect. These seemingly contradictory findings might be attributable to interactions between the relevance and the predictability of the stimuli used. To clarify the effects of expectation on visual detection sensitivity and dissociate them from those of relevance cues and primes, we conducted two continuous flash suppression experiments. In each trial, participants viewed a thin gray bar in one eye and an animated rectangular patch in the other eye. Expectation was manipulated by the inclusion of a cue, which predicted (with 80% validity) the orientation of the bar in half of the trials. In the first experiment, participants were asked to quickly press a key only if they detected a bar of a certain orientation (the relevance manipulation). In the second experiment, the cues were identical to the targets predicted by them in half of the trials; in the remaining trials, colored circles were used instead (the cue type manipulation). When the masked bar did not warrant a response, detection performance was poorer (in terms of both visibility reports and localization performance) in invalid cue trials relative to both valid cue and nonpredictive cue trials. These differences were absent when the presented stimulus was behaviorally relevant. Primes and abstract predictive cues, when valid, improved detection performance to similar extents. Our results suggest that, when both are at play, the effects of attentional priorities on visual detection thresholds override those of prior expectations. They also indicate that predictive cueing and repetition priming may rely on similar neural mechanisms.
Meeting abstract presented at VSS 2017