Abstract
A critical step in understanding any perceptual process is determining the underlying units over which it operates. For example, decades of research have demonstrated that the underlying units of visual attention are often visual objects. This conclusion has been supported by the demonstration of a 'same-object advantage': for example, nonpredictive cues lead to faster target responses when cue and target both occur on the same object versus when they occur on distinct objects, equating for spatial distance. Such effects have been well characterized in the context of spatial attention, but to our knowledge no previous studies have investigated the possibility of analogous effects for temporal attention. Here we explore whether a particular class of temporally-extended auditory "objects" — rhythmic phrases — might similarly serve as units of temporal attention. Participants listened to a repeating sequence of rhythmic phrases (3-4 seconds each) of a low-pitch tone while trying to quickly detect sporadic higher-pitch target tones, each of which was preceded by a fully-predictive cue tone. While equating for the brute duration of the cue-target interval, some cue-target pairs occurred within the same rhythmic phrase, while others spanned a boundary between phrases. We observed a significant "same-phrase" advantage: participants responded more quickly to Within-Phrase than Between-Phrase targets. These results reveal a new phenomenon of temporal attention, as well as a new analogue between visual and auditory processing. In particular, they suggest a more general interpretation of typical object-based effects in visual attention: just as the structure of a scene will constrain the allocation of attention in space, so too might the structure of a sequence constrain the allocation of attention in time. Thus, rather than being driven by particular visual cues, per se, "object-based attention" may reflect a more general influence of perceived structure of any kind on attention.
Meeting abstract presented at VSS 2012