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The location of overt attention affects the bias in acceleration perception: A preliminary study
Anja Podlesek & Maja Fesel Martinčevič
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Written in English. | Published: June 6, 2003
Abstract: Visual attention affects spatial and temporal processing of stimuli and consequently also affects motion perception. This study examined whether directing overt attention to different positions in the visual field affects the perception of motion acceleration. A square target travelled horizontally across the computer screen, from left to right or from right to left. Distance and duration of motion were varied. Throughout the trial, overt attention was directed to the leftmost part, to the centre, or to the rightmost part of the travelling path of the target. During the course of motion a control digit was presented at a fixated location. Participants had to identify the digit and assess how velocity of the moving target changed with time. The results showed that directing attention to different positions had an effect on acceleration perception, and that the magnitude of this effect increased with the length of the path. When attention was directed to a position that corresponded with the beginning of the path, perceived velocity of the moving target decreased with time. When attention was directed to the end of the path, perceived velocity of the moving target was constant or slightly increased with time. Different explanations of the bias in acceleration perception and its change due to fixation location are offered. Results are discussed within the context of change in target eccentricity, functioning of attention (through the formation of an object file, the perceptual acceleration, and the spatial distribution of attention), and temporal dynamics of the functioning of the motion detectors network.
Keywords: motion perception, acceleration perception, visual spatial attention, eccentricity, perceptual acceleration
