Visual reaction time and size constancy

Irene Sperandio, Silvia Savazzi, Richard L. Gregory, Carlo A. Marzi

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


We carried out six experiments to find out whether simple manual reaction time (RT) to flux-equated visual stimuli of different size is modulated by size constancy or by the retinal angle subtended by the stimuli. We found that RT decreased with the increase in perceived stimulus size rather than retinal angle and that this relationship depended on the use of familiar 3-D-like stimuli and on the availability of other size-constancy cues. Thus, a stereotyped speeded motor response, such as that employed in a simple RT paradigm, is modulated by size constancy, as is the case with perceptual judgments. The present results provide original evidence on the relationship between simple RT and perception. © 2009 a Pion publication.
Original languageEnglish
Pages (from-to)1601-1609
Number of pages9
Issue number11
Publication statusPublished - 1 Jan 2009

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