Abstract
Task-dependence is an important topic in the search for neural correlates of perception - action relationships. The present study focuses on the extent to which the rod-and-frame illusion (RFI) is task-dependent. In three experiments, participants were asked to perform different visuomotor tasks with responses that consisted either of (i) replicating the orientation of the stimulus rod by rotating a line on a computer screen through a series of key presses, (ii) making a perceptual judgment about the rod orientation in a forced-choice paradigm, or (iii) rotating and propelling a hand-held cylinder in order to replicate the orientation of the stimulus rod. The effects of the RFI proved robust and constant, irrespective of whether the task required perceptual or motor processes. Our findings add to the generality of the claim that visual illusions are task-dependent. The task-independence of the RFI with delayed responses reported here refines the results of Dyde and Milner (2002 Experimental Brain Research 144 518 - 527), who found task-dependent effects of the RFI under no-delay conditions.
