Hamilton, G. and Goddard, Paul and Baldwin, Julie and Pollux, Petra and Bourke, Patrick (2002) Generating ogives to (i) analyse perceptual changes associated with ambiguous figures, and (ii) reaction times in an inhibition-of-return (IOR) task. In: 25th European Conference on Visual Perception, 25th - 29th August 2002, Glasgow.
|Item Type:||Conference or Workshop Item (Poster)|
ECVP_2002_-_Paul_Goddard.pdf - Extended Abstract
|Divisions:||College of Social Science > School of Psychology|
|Abstract:||The perceptual changes (PCs) associated with viewing an ambiguous figure like the Necker cube (NC) can be considered as a series of independent events in time. The time between successive PCs is then percept duration, and the frequency distribution of percepts plotted against duration is adequately modelled by a gamma distribution (Borsellino et al, 1972 Kybernetik 10 139 - 144). A logarithmic transformation on the duration scale enabled us to model the subsequent distribution with a Gaussian. The cumulative Gaussian fitted to the normalised ogive allowed simple comparison of observer performance in different conditions. We found no differences between ogives generated for the standard 'cube-up' and 'cube-down' 3-D perceptual alternatives. When observers recorded 2-D perceptual alternatives, the ogives were shallower and shifted to the right. This suggests that the neural mechanisms governing PCs between 3-D and 2-D perceptual alternatives differ from those that govern the PCs between the opposing 3-D perceptual alternatives of 'cube-up' and 'cube-down'. Further, we show that the same analysis can be applied to reaction times generated in an inhibition-of-return (IOR) task. We argue that this form of analysis is superior to other more commonly reported methods for both attentional and PC data.|
|Date Deposited:||05 Nov 2010 14:10|
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