Illusory line motion is not caused by object-differentiating mechanisms or endogenous attention

Abstract

Christie and Klein [2005. Does attention cause illusory line motion? Perception & Psychophysics, 67(6), 1032–1043] published line motion ratings consistent with illusory line motion (ILM) after peripheral endogenous cues but not central arrow cues. When attention was directed endogenously on the basis of the shape of one of two peripherally presented objects, participants reported small, but significant motion away from the attended object, and this was attributed to participant bias, or to a peripherally directed object-based attention system endogenously recruited to differentiate the peripheral shapes. By using a unique cueing method with identical peripheral markers, but still allowing them to act as cues, the findings of Christie and Klein Experiment 4 were replicated. This reduces the likelihood that object discrimination or object attention mechanisms are responsible for the reported ILM-like effects.

Keywords:

• Attention
• Orienting
• Endogenous cue
• Exogenous cue
• Illusory movement
• Visual illusion
• Response bias

This research was funded by a grant to Raymond M. Klein from the National Sciences and Engineering Research Council of Canada.