Abstract
A sensory cancellation effect is presumed to result when participants move 'congruently' during a visual discrimination task. Indirect evidence for this has been shown (Miall et al., 2006), but in this study, only background stimuli were incongruent/ congruent, the target stimuli were always movement incongruent. Therefore, we manipulated target and stimulus-movement congruency during arm flexion/ extension movements. Congruent stimuli were directionally in-phase. Incongruent stimuli were directionally anti-phase, AP or random. Nine participants responded to a change in colour of hand images. Voice RTs were recorded from trials lasting ~200 s (~20 RTs). RTs were faster when the stimuli were sequential vs. random, when not moving. This effect was magnified during movement (Stim x Move, p = .01). Of interest was a Stimulus x Target Congruency interaction (p<.05) when moving. For sequential stimuli, RTs were faster when the target position was incongruent (at a different location) to the movement, but the opposite was found for random conditions. For AP, RTs were generally slower and target congruency did not affect RT. Therefore, movement congruency aids RT when there is no predictability in the visual stimuli, it has no effect on RT when the stimulus is predictable but not congruent throughout the movement and in support of previous research, it slows RT when stimuli predictability is high, arguably acting to gate redundant sensory information.Acknowledgments: Research supported by NSERC grant (Nicola Hodges)