Abstract
If a dot is flashed in perfect alignment with a pair of dots rotating around the visual fixation point, most observers perceive the rotating dots as being ahead of the flashing dot (flash-lag effect). This perceptual effect has been interpreted to result from the perceptual extrapolation of the moving dots, the differential visual latencies between flashing and moving stimuli, as well as the modulation of attentional mechanisms. Here we attempted to uncouple the attentional effects brought about by the spatial predictability of the flashing dot from the sensory effects dependent on its visual eccentricity. The stimulus was a pair of dots rotating clockwise around the fixation point. Another dot was flashed at either the upper right or the lower left of the visual field according to three separate blocked situations: fixed, alternate and random positions. Twenty-four participants had to judge, in all three situations, the location of the rotating dots in relation to the imaginary line connecting the flashing dot and the fixation point at the moment the dot was flashed. The flash-lag effect was observed in all three situations, and a clear influence of the spatial predictability of the flashing dot on the magnitude of the perceptual phenomenon was revealed, independently of sensory effects related to the eccentricity of the stimulus in the visual field. These findings are consistent with our proposal that, in addition to sensory factors, the attentional set modulates the magnitude of the differential latencies that give rise to the flash-lag phenomenon.
Highlights
Presented at the XVII Annual Meeting of the Federação de Sociedades de Biologia Experimental, Salvador, BA, Brazil, August 28-31, 2002
If a dot is flashed in perfect alignment with a pair of dots rotating around the visual fixation point, most observers perceive the rotating dots as being ahead of the flashing dot
The flash-lag effect was observed in all three situations, and a clear influence of the spatial predictability of the flashing dot on the magnitude of the perceptual phenomenon was revealed, independently of sensory effects related to the eccentricity of the stimulus in the visual field
Summary
Presented at the XVII Annual Meeting of the Federação de Sociedades de Biologia Experimental, Salvador, BA, Brazil, August 28-31, 2002. This perceptual effect has been interpreted to result from the perceptual extrapolation of the moving dots, the differential visual latencies between flashing and moving stimuli, as well as the modulation of attentional mechanisms. We attempted to uncouple the attentional effects brought about by the spatial predictability of the flashing dot from the sensory effects dependent on its visual eccentricity.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.