Are we overthinking it? Haptic perception of geographic slant is accurate when embedded within a secondary task

摘要

Recent research (Hajnal, Wagman, Bunch, & Doyon, 2014) suggested that geographic slants feel steeper than they look. Visual perception of the stand-on-able-ness of an inclined surface is generally accurate and corresponds to an action boundary of approximately 30 degrees. Haptic perception underestimates the action boundary in laboratory settings. This may occur because more overt attention is dedicated to the perceptual task than is typical in performing everyday behaviors. Does focused attention lead to overthinking actions such as upright standing? When perceiving maximum reaching distance participants are more accurate when the judgment is embedded in another perception-action task (Heft, 1993). It was hypothesized that embedding haptic perception of stand-on-ability within another perception-action task would bring haptic judgments in line both with visual judgments and action capabilities. Specifically, haptic judgments were expected to be more accurate and judgments made near the transition point (30?°-36?°) would show longer response times and lower confidence ratings (Wagman & Hajnal, 2014). Observers placed a foot onto an occluded ramp while viewing a dangling light socket overhead and reported whether they would be able to screw a light bulb into the socket if they were allowed to stand on the ramp. Socket height was scaled to the observera??s maximal vertical reach and presented at that height as well as 5a?? above or below. Ramp presentations consisted of 7 angles ranging from 12?° to 48?° in 6?° increments. Perceptual boundaries were compared against actual action boundaries, i.e., the point at which the ramp no longer supports upright standing. Haptic perceptual boundaries (36.9?°) matched action boundaries (34.0?°). Confidence was lowest and response time was the longest at the angle nearest to the transition point (36?°). Results suggest that the affordance of stand-on-ability is best studied in the context of embedded everyday tasks.