We investigated the effect of attending to a specific period in time on low-intensity target detection in two psychophysical experiments. In the first experiment, participants were asked to detect a deviant target within a regular distractor sequence. Five experimental conditions were used: in the auditory-only condition, the target was a frequency modulated tone presented in a train of 14 pure tone distractors. In the visual-only condition, the target was a Gabor patch with a higher contrast compared to Gabor distractors. In all three AV conditions, auditory and visual trains of distractors were presented simultaneously but each condition differed for target type (i.e.: auditory-only, visual-only or AV target). In the second experiment, participants performed a frequency-discrimination instead of simple detection task. In both experiments, the target could appear either after a short or a long interval (400 or 1400 ms after first stimulus onset, respectively). We manipulated temporal expectancy (TE) by presenting trials in ‘expect-early’ blocks which consisted of 85% trials with early targets and 15% with late targets and vice versa for ‘expect-late’ blocks. We found that expecting a sensory event at a specific time point significantly enhances detection performance. This expectancy benefit is particularly pronounced for the AV conditions in the expect-early compared to late condition. In the discrimination experiment, a significant TE benefit was observed only in the AV condition with AV target. Collectively, our data extend previous findings from unisensory expectancy and demonstrate a selective TE effect being more pronounced for AV compared to unisensory conditions.

temporal expectancy; audiovisual; integration; psychophysics