FIGURE 1.

Experimental design and timing of visual and tactile stimulation in an example trial (touch/dot on right hand, no touch/no dot on left hand). In Experiment 1, task-irrelevant viewed touch and no-touch events were, in separate blocks, passively received (A) or actively sought (B). In Experiment 2, bright green dots were shown on or above the index finger pads instead of touch or no-touch events (C). Replacement of neutral with touch or no-touch images, and vice versa, gave the impression of apparent motion of the pencil [passive touch trials (A)] or finger [active touch trials (B)] resulting in touch or no touch. Task-relevant tactile stimuli were presented to the observer’s left and right index finger pad either simultaneously with each touch/no-touch/dot image (concurrent touch trials) or 1000 ms later (in delayed touch trials). Observers fixated on a white central cross, which changed color at the end of the trial to indicate whether the intensity judgment response should be given (green) or withheld (red).