Causal Dynamics of Scalp Electroencephalography Oscillation During the Rubber Hand Illusion.
Brain Topogr
; 30(1): 122-135, 2017 01.
Article
in En
| MEDLINE
| ID: mdl-27620801
ABSTRACT
Rubber hand illusion (RHI) is an important phenomenon for the investigation of body ownership and self/other distinction. The illusion is promoted by the spatial and temporal contingencies of visual inputs near a fake hand and physical touches to the real hand. The neural basis of this phenomenon is not fully understood. We hypothesized that the RHI is associated with a fronto-parietal circuit, and the goal of this study was to determine the dynamics of neural oscillation associated with this phenomenon. We measured electroencephalography while delivering spatially congruent/incongruent visuo-tactile stimulations to fake and real hands. We applied time-frequency analyses and calculated renormalized partial directed coherence (rPDC) to examine cortical dynamics during the bodily illusion. When visuo-tactile stimulation was spatially congruent, and the fake and real hands were aligned, we observed a reduced causal relationship from the medial frontal to the parietal regions with respect to baseline, around 200 ms post-stimulus. This change in rPDC was negatively correlated with a subjective report of the RHI intensity. Moreover, we observed a link between the proprioceptive drift and an increased causal relationship from the parietal cortex to the right somatosensory cortex during a relatively late period (550-750 ms post-stimulus). These findings suggest a two-stage process in which (1) reduced influence from the medial frontal regions over the parietal areas unlocks the mechanisms that preserve body integrity, allowing RHI to emerge; and (2) information processed at the parietal cortex is back-projected to the somatosensory cortex contralateral to the real hand, inducing proprioceptive drift.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Parietal Lobe
/
Proprioception
/
Visual Perception
/
Touch Perception
/
Illusions
Limits:
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
Brain Topogr
Journal subject:
CEREBRO
Year:
2017
Type:
Article
Affiliation country:
Japan