Spatial limits on the nonvisual self-touch illusion and the visual rubber hand illusion: Subjective experience of the illusion and proprioceptive drift

• Published in: Consciousness and cognition 2013-06, Vol.22 (2), p.613-636
• Main Authors: Aimola Davies, Anne M., White, Rebekah C., Davies, Martin
• Format: Article
• Language: English
• Subjects: Action; Adolescent; Adult; Alignment; Biological and medical sciences; Body; Body Image; Distance; Female; Fundamental and applied biological sciences. Psychology; Humans; Illusions - physiology; Location of illusion; Male; Multimodal perception; Perception; Physical Stimulation; Proprioception; Proprioception - physiology; Proprioceptive drift; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rubber hand illusion; Self-touch illusion; Sensory integration; Surveys and Questionnaires; Tactile perception; Touch Perception - physiology; Vision; Visual Perception - physiology; Young Adult
• ISSN: 1053-8100; 1090-2376
• DOI: 10.1016/j.concog.2013.03.006

•A nonvisual self-touch illusion and a visual rubber hand illusion were tested.•Assessment: agreement ratings, time of illusion onset, and proprioceptive drift.•Methods: distance (15cm, 30cm, 45cm, 60cm) and alignment (0°, 90°) manipulations.•Subjective experience of the illusion is sometimes diminished but never abolished.•Subjective experience (ratings, time) and proprioceptive drift dissociate. The nonvisual self-touch rubber hand paradigm elicits the compelling illusion that one is touching one’s own hand even though the two hands are not in contact. In four experiments, we investigated spatial limits of distance (15cm, 30cm, 45cm, 60cm) and alignment (0°, 90° anti-clockwise) on the nonvisual self-touch illusion and the well-known visual rubber hand illusion. Common procedures (synchronous and asynchronous stimulation administered for 60s with the prosthetic hand at body midline) and common assessment methods were used. Subjective experience of the illusion was assessed by agreement ratings for statements on a questionnaire and time of illusion onset. The nonvisual self-touch illusion was diminished though never abolished by distance and alignment manipulations, whereas the visual rubber hand illusion was more robust against these manipulations. We assessed proprioceptive drift, and implications of a double dissociation between subjective experience of the illusion and proprioceptive drift are discussed.