Shifts of visual attention to multiple simultaneous location cues.

Abstract

Single and simultaneous multiple location cues were presented a brief period of time before the onset of targets that observers were required to identify. Single and multiple cueing effects were similar, even when targets were presented at locations "in between" pairs of cues. This implies that pairs of direct stimulus cues are not processed by an attentional focus of variable spatial extent that encompasses both cued locations. If this were the case, then targets presented in between cued locations would fall within such an attentional focus and identification response times should have been reduced. The increase in these response times that actually occurred when a target was presented at uncued locations in between a pair of cued locations suggests that pairs of cued locations are encoded independently by an operation called spatial indexing. A multiple indexing proposal and its role in mediating visual attention shifts initiated by direct stimulus cues is described.

Multiple-location access in vision: Evidence from illusory line motion.

“…Castiello and Umilt~ (1992) reported attentional splitting only when existing objects explicitly marked the location and spatial extent of the locations to be attended. Wright (1994) reported similar results in experiments using single and multiple cuing designs. Regardless of whether one or two locations had been cued, a benefit in response time was observed to targets appearing at cued locations but not at uncued or between cued locations.…”

“…This difference suggests that although an indexing mechanism may exist, the mechanism's eventual throughput in any task is likely to be lower than the indexing mechanism's capacity would suggest. This observation may be an important one regarding studies that purport to find attentional processing at multiple locations (Castiello & Umilth, 1992;Kramer & Hahn, 1995;Wright, 1994). Visual processes required to execute a task may enforce whether information can be accessed in parallel.…”

Goal-driven modulation of stimulus-driven attentional capture in multiple-cue displays

“…According to this view, sensory activity generated by an abrupt-onset stimulus produces location-specific processing facilitation that is independent of focused attention (e.g., Tassinari, Aglioti, Chelazzi, Peru, & Berlucchi, 1994;Tepin & Dark, 1992;Wright, 1994;Wright & Richard, 2003). In this case, sensory activity might initiate operations that either speed or facilitate the processing of information that occurs at that location (perhaps by "revving up" processing to provide a "head start" relative to processing at other locations) or by speeding up the opening of an attention channel at those locations (e.g., LaBerge & Brown, 1989).…”

Spatiotemporal Segregation in Visual Search: Evidence From Parietal Lesions.

“…Efficient selection of the target may be quite difficult, for instance, when the target shares its features with the surrounding distractors or when attention is drawn to the wrong location by a more salient object. Under other circumstances, selection can be quite effortless, for example, when the target carries a salient feature distinguishing it from the distractors or when observers are cued toward its location (Duncan & Humphreys, 1989;Pylyshyn et al, 1994;Theeuwes, 1991;Theeuwes, Kramer, & Atchley, 1999;Treisman & Gelade, 1980;Wright, 1994).…”