Somatosensory Prior Entry
Single Paper Presentation

Mark Yates
Department of Psychology, University of Melbourne

Michael Nicholls
Department of Psychology, University of Melbourne

     Abstract ID Number: 84
     Full text: Not available
     Last modified: May 30, 2007
     Presentation date: 07/05/2007 4:10 PM in Quad General Lecture Theatre
     (View Schedule)

Abstract
The time that we perceive sensory events to occur does not necessarily match the actual timing of those events. This study investigated the effect of location of attention on the perceived timing of brief somatosensory stimuli. Subjects (n = 12) were given two taps (one tap to the index finger of one hand, and one tap to the thumb of the other hand) and judged which tap (index finger or thumb) was delivered first. Taps were separated by 10 different intervals (ranging from -480 to 480ms). Prior to receiving the taps, subjects’ spatial attention was manipulated either a) exogenously (Experiment 1) using brief taps to either the left or right hand or b) endogenously (Experiment 2) using centrally presented symbolic cues (arrows). It was hypothesised that stimuli presented to the attended side would be perceived more rapidly (i.e. with a shorter perceptual latency) than unattended stimuli. Results support this hypothesis for the exogenously-cued condition but not for endogenously-cued condition. Previous research has demonstrated a similar effect for visual stimuli (Shore et al., 2001). This study, which extends this result to somatosensory perception (for exogenous cueing) indicates that the phenomenon represents a more global feature of the perceptual system, possibly mediated by a common modality-independent mechanism.