Purchase this article with an account.
Slobodan Markovic; Figural constraints on contour discontinuity detection. Journal of Vision 2008;8(6):585. doi: 10.1167/8.6.585.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
In this study the effect of figural goodness on the detection of contour discontinuity was investigated. Two opposite hypotheses of goodness effect were evaluated. The Assimilation hypothesis: good figures are more tolerant to the contour degradation than the poor ones (e.g. a circle with a small gap on its contour is perceptually categorized as a circle, not as an arc). The Sensory detection hypothesis: good figures are more sensitive to the contour degradation than the poor ones (e.g. the small gap on a contour of a circle is easier to detect than the gap on an ameboid figure). In this study the dimension good-poor was defined through four stimulus dimensions: symmetric-asymmetric, simple-complex, compact-disperse and oval-sharp (good figure is an approximation of a circle, i.e perfect symmetric, simple, compact and oval form). According to these dimensions the pairs of figures were generated. Each figure had its complete contour and incomplete contour (small gap) version. Twenty subjects were asked to judge whether the presented figure had a gap (visual search task: the gap was a target). RT was recorded. The analysis of variance indicated the significant effect of completeness: the gap was detected faster in an incomplete than in a complete contour condition. The effect of the factor stimulus dimension and the interaction dimension x completness were significant. Partial analysis has shown significant effects of the dimension simple-complex: the gap was detected faster in simple than in complex figures. The effect of the dimension symmetric-asymmetric was marginally significant: the gap was detected faster in symmetric than in asymmetric figures. These results are in line with the Sensory detection hypothesis suggesting that the contour discontinuity is detected faster on good than in poor figures.
This PDF is available to Subscribers Only