Attentional sampling of multiple wagon wheels

James S P Macdonald (1) , Patrick Cavanagh (2, 3) , Rufin Vanrullen (4)

1 Department of Experimental Psychology
2 LPP - Laboratoire psychologie de la perception
3 Department of Psychology, Harvard University - Department of Psychology, Harvard University
4 CERCO - Centre de recherche cerveau et cognition

Attending to a periodic motion stimulus can induce illusory reversals of the direction of motion. This continuous wagon-wheel illusion (c-WWI) has been taken to reflect discrete sampling of motion information by visual attention. An alternative view is that it is caused by adaptation. Here, we attempt to discriminate between these two interpretations by asking participants to attend to multiple periodic motion stimuli: the discrete attentional sampling account, but not the adaptation account, predicts a decrease of c-WWI temporal-frequency tuning with set size (with a single periodic motion stimulus the c-WWI is tuned to a temporal frequency of 10 Hz). We presented one to four rotating gratings that occasionally reversed direction while participants counted reversals. We considered reversal overestimations as manifestations of the c-WWI, and determined the temporal-frequency tuning of the illusion for each set size. Optimal temporal frequency decreased with increasing set size. This outcome favours the discrete attentional sampling interpretation of the c-WWI, with a sampling rate for each individual stimulus dependent on the number of stimuli attended.

Mots clés: Divided attention; Inattention; 2D Motion; Temporal processing

Domaines: Psychologie; Sciences cognitives

James S P Macdonald, Patrick Cavanagh, Rufin Vanrullen. Attentional sampling of multiple wagon wheels. Attention, Perception, and Psychophysics, 2014, 76, pp.64-72. ⟨10.3758/s13414-013-0555-5⟩. ⟨hal-01298962⟩