Fig 1.
Visual stimuli and experimental setup.
(A) Screenshots of the videos depicting touch to either a human hand in a plausible orientation (left), a sponge (middle) or a human hand in an implausible orientation (right). Examples of each of the three condition videos can be found on the OSF page for this project: osf.io/grw57. (B) Participants watched videos of a hand or sponge being touched and indicated whether the seen touch or the felt touch came first by pressing one of two response keys with their left hand. To mask any noise from the tactile stimulator, participants listened to white noise via headphones. Viewing distance was kept constant with a chin rest.
Fig 2.
‘Visual-first’ responses and JND results.
(A) Averaged proportion of ‘visual-first’ responses plotted against SOAs for the three conditions. The averaged ‘visual-first’ responses for the different conditions are very similar. Note that we fitted sigmoid functions to the data of each participant and then calculated JNDs for each participant and condition. (B) Bar graph showing mean JNDs for each of the three conditions with JND estimates from individual participants indicated by scatter points. (C) Bar graphs showing the mean JND differences for the two comparisons. JND differences from individual participants are indicated by scatter points and show high between-subject variability (ΔJND form = JND hand plausible orientation–JND sponge and ΔJND orientation = JND hand plausible orientation–JND hand implausible orientation). Error bars represent 95% CI.
Fig 3.
Sequential plotting of the Bayes factors.
We compared the two conditions: plausible hand orientation versus sponge (left panel) and plausible hand orientation versus implausible hand orientation (right panel). Sequential plotting of the BF shows that the BFs start to converge at N = 20 (plausible hand orientation versus sponge) and N = 24 (plausible hand orientation versus implausible hand orientation), which in both cases provides moderate evidence to support the null hypothesis.
Table 1.
Selected papers that directly test visual context (form and orientation) effects on temporal and spatial integration of visual, tactile and proprioceptive bodily inputs.