Figure 1
From: Confidence is higher in touch than in vision in cases of perceptual ambiguity
The Vertical-Horizontal Illusion (a–c) showing Inverted T stimuli were explored by touch and by vision. The vertical bar ranged from 18 to 34 mm, which was compared to a horizontal bar of fixed size of 30 mm. Stimuli could be clear-cut (a,c) or ambiguous (b) in the two modalities. Perceptual responses were verbal reports as to whether the vertical bar was ‘shorter’ or ‘longer’ than the horizontal bar. Confidence judgements were given on a scale from very uncertain (1) to very certain (7). (a) Probability of judging the vertical bar to be longer than the horizontal bar as a function of the size of the vertical bar. Error bars show within-participant standard errors. (b) Point of subjective equality (PSE) for each participant in each modality.
