Relationship between sensitivity to visuotactile temporal discrepancy and the rubber hand illusion

Area of Science:

• Neuroscience
• Psychology
• Human Perception

Background:

• The rubber-hand illusion (RHI) occurs when synchronous tactile stimulation of a real and an artificial hand leads to the sensation of ownership over the artificial hand.
• Previous research indicates that increasing visual feedback delay significantly reduces the RHI.
• Understanding the relationship between delay perception and illusion attenuation is crucial for elucidating the underlying neural mechanisms.

Purpose of the Study:

• To investigate the relationship between the attenuation of the rubber-hand illusion (RHI) and the ability to detect visual feedback delays in tactile stimulation.
• To differentiate the processing of body schema and body image in relation to temporal discrepancies in sensory feedback.

Main Methods:

• Two experiments were conducted: a standard RHI experiment and a visuotactile asynchrony detection experiment.
• Participants received tactile stimulation on their hand, with varying visual feedback delays presented for an artificial hand.
• Subjects judged the synchrony between tactile sensation and visual feedback, and their RHI experience was quantified.

Main Results:

• The RHI was significantly attenuated as the visual feedback delay increased, consistent with prior findings.
• Proprioceptive drift demonstrated a linear decline with increasing delay.
• Delay detection performance was best described by a non-linear (logistic) function, and the illusion score exhibited an intermittent pattern.

Conclusions:

• Proprioceptive drift appears to be associated with the processing of the body schema.
• The detection of delay and the subjective experience of the RHI are more closely linked to body image processing.
• These findings suggest distinct neural pathways for processing temporal information related to body ownership and spatial body representation.