Purchase this article with an account.
Catalina Olavarria, Tyler Surber, Joseph Clark, Jonathan Doyon, Alen Hajnal; Visual and haptic perception of the affordance of upright stance.. Journal of Vision 2017;17(10):1051. doi: 10.1167/17.10.1051.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Past research by Hajnal, Wagman, Doyon, and Clark (2016) found apparent differences among haptic and visual perception of the affordance of stand-on-ability. One reason for this discrepancy might be due to the imprecision and method of measurement. Instead of using the classic psychophysical method of constant stimuli, we employed a dynamic converging staircase method of stimulus presentation. Our goal was to obtain a reliable estimate of perceptual and action boundaries within a behaviorally relevant precision level of 1.5 degrees of geographical slant. We used an adjustable sturdy ramp apparatus as the stimulus, and had three groups of participants either visually inspect the surface, place their right foot occluded from view unto the ramp surface, or place their foot on the ramp while allowed to look at it, in the visual, haptic, or full cue condition, respectively. Each trial was presented in an ascending or descending fashion by slowly moving the ramp up or down, respectively, until the participant perceived the action boundary, i.e. the steepest slope that still afforded upright stance. After the perceptual trials we measured the actual action boundary using the same procedure, by allowing participants to attempt to stand on the ramp. The action boundary was the average between the lowest false alarm trial and steepest hit trial within a 1.5 degree margin of difference based on several ascending and descending stimulus presentation sequences. The results revealed that visual and haptic perception were equivalent with the combined condition, and that all corresponded to the action boundary. Curiously, it took more attempts to detect the action boundaries than perceptual ones. The results support the postulate of equivalence among perceptual systems proposed by Gibson (1966), and the idea of correspondence between perception and action which is the cornerstone of affordance theory.
Meeting abstract presented at VSS 2017
This PDF is available to Subscribers Only