Viewer perspective affects central bottleneck requirements in spatial translation tasks.

A psychological refractory period (PRP) approach and the locus of slack logic were applied to examine the novel question of whether spatial translation processes can begin before the central bottleneck when effector or noneffector stimuli are processed from an egocentric (viewer-centered) perspective. In single tasks, trials requiring spatial translations were considerably slower than trials without translations (Experiment 1). Dual tasks consisted of tone discriminations (Task 1) and spatial translations (Task 2) using PRP methods with different manipulations on perceptual and response demands. When a viewer-centered perspective was used, the effect of spatial translation was reduced at short compared with long stimulus onset asynchronies (SOAs) when the potential for code overlap between tasks was removed (Experiments 2, 3, and 4); this finding supports the view that translation processes can begin before the central bottleneck. When an allocentric (non-viewer-centered) perspective was used (Experiment 5), the slowing associated with spatial translation was additive with SOA, suggesting that the processes of spatial translation cannot begin before the bottleneck. These findings highlight the importance of viewer perspective on central bottleneck requirements. Findings are further discussed in relation to the dorsal-ventral model of action and perception.