Am I seeing my hand? Visual appearance and knowledge of controllability both contribute to the visual capture of a person's own body.
When confronted with complex visual scenes in daily life, how do we know which visual information represents our own hand? We investigated the cues used to assign visual information to one's own hand. Wrist tendon vibration elicits an illusory sensation of wrist movement. The intensity of this illusion attenuates when the actual motionless hand is visually presented. Testing what kind of visual stimuli attenuate this illusion will elucidate factors contributing to visual detection of one's own hand. The illusion was reduced when a stationary object was shown, but only when participants knew it was controllable with their hands. In contrast, the visual image of their own hand attenuated the illusion even when participants knew that it was not controllable. We suggest that long-term knowledge about the appearance of the body and short-term knowledge about controllability of a visual object are combined to robustly extract our own body from a visual scene.
ATR Brain Information Communication Research Laboratory Group, Kyoto 619-0288, Japan. n.hagura@ucl.ac.uk
Nobuhiro
N
Hagura
Satoshi
S
Hirose
Michikazu
M
Matsumura
Eiichi
E
Naito
D000328:Adult; D003463:Cues; D004558:Electric Stimulation; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D007699:Kinesthesis; D008297:Male; D009903:Optical Illusions; D010470:Perceptual Masking; D010775:Photic Stimulation; D013710:Tendons / Q000502:physiology; D014796:Visual Perception; D055815:Young Adult