Abstract
Both the sensory modality and the timing of relevant events often vary predictably in natural environments, so that it is beneficial to adapt the sensory system to such variations. Indeed, statistical information about target sensory modality and/or timing facilitates behavioral responses—called expectation effects. Responses are also facilitated by short-term repetitions of target sensory modality and/or timing—called priming effects. We examined how expectation and priming effects interacted when expectations about target modality (auditory vs. visual) and timing (short vs. long cue-to-target interval) were concurrently manipulated. Target-modality expectation (80% auditory with 20% visual target, or vice versa) was manipulated across participants, while target-timing expectation (80% short with 20% long cue-to-target interval, or vice versa) was manipulated across blocks. Target-modality and target-timing expectations speeded response times (faster responses when targets were presented in the expected modality and/or at the expected timing) in an additive manner, suggesting that they operate relatively independently. Responses were also faster when the modality and/or timing of targets were repeated across trials—priming effects. Importantly, the interactions between expectation and priming were domain specific. For directing attention to target modality, modality-priming effects predominated for auditory targets whereas modality-expectation effects predominated for visual targets. For directing attention to target timing, temporal-expectation effects were observed only when temporal-priming effects were absent (i.e., when the timing changed relative to the preceding trial). Crucially, modality priming did not interact with temporal expectation, and temporal priming did not interact with modality expectation. Thus, the interactions between "global" statistical and "local" priming processes appear to be controlled separately within the mechanisms that direct attention to specific sensory modalities and within the mechanisms that direct attention to specific temporal intervals. These results may suggest that the sensory system concurrently optimizes attentional priorities within sensory modality and timing domains.
Meeting abstract presented at VSS 2018