Paradoxical cross-over due to attention to high or low spatial frequencies.
The mechanisms underlying the right hemisphere's dominance for spatial and attentional functions lacks a comprehensively explanation. For example, perceptual biases, as observed in line bisection and related tasks, might be caused by an attentional asymmetry or by perceptual processes such as a specialization of the left and right hemisphere for high and low spatial frequencies (SFs), respectively. Here we used the gratingscales task to measure perceptual bias in SF judgements, and we cued participants' attention either to high or low SFs. Participants showed a leftward bias when comparing the high SF components of the stimulus, and a rightward bias when comparing the low SF components-opposite to what would be expected from a hemispheric lateralization for SFs. Two control experiments used different strategies to manipulate the width of the attentional window. However, we observed no influence on perceptual bias, thus ruling out the possibility that the results in Experiment 1 were due to differences in attentional window size. These data support the idea of an attentional asymmetry underlying perceptual bias. Our results provide novel support for the role of attentional asymmetry in perceptual biases.
Niemeier
Matthias
M
Centre for Computational Cognitive Neuroscience, Department of Psychology, University of Toronto at Scarborough, 1265 Military Trail, Toronto MIC 1A4, Canada. niemeier@utsc.utoronto.ca
Stojanoski
Boge
B
Singh
Vaughan W A
VW
Chu
Eddie
E
D000328:Adult; D001288:Attention / Q000502:physiology*; D003463:Cues; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D010468:Perceptual Disorders / Q000503:physiopathology; D010469:Perceptual Distortion / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*