Shared electrophysiology mechanisms of body ownership and motor imagery

Abstract

Although we feel, see, and experience our hands as our own (body or hand ownership), recent research has shown that illusory hand ownership can be induced for fake or virtual hands and may be useful for neuroprosthetics and brain-computer interfaces. Despite the vast amount of behavioral data on illusory hand ownership, neuroimaging studies are rare, in particular electrophysiological studies. Thus, while the neural systems underlying hand ownership are relatively well described, the spectral signatures of body ownership as measured by electroencephalography (EEG) remain elusive. Here we induced illusory hand ownership in an automated, computer-controlled manner using virtual reality while recording 64-channel EEG and found that illusory hand ownership is reflected by a body-specific modulation in the mu-band over fronto-parietal cortex. In a second experiment in the same subjects, we then show that mu as well as beta-band activity in highly similar fronto-parietal regions was also modulated during a motor imagery task often used in paradigms employing non-invasive brain-computer interface technology. These data provide insights into the electrophysiological brain mechanisms of illusory hand ownership and their strongly overlapping mechanisms with motor imagery in fronto-parietal cortex. They also highlight the potential of combining high-resolution EEG with virtual reality setups and automatized stimulation protocols for systematic, reproducible stimulus presentation in cognitive neuroscience, and may inform the design of non-invasive brain-computer interfaces.

A threat to a virtual hand elicits motor cortex activation

“…A recent paper (Evans and Blanke, 2013) showed that synchronous visual-tactile feedback during the hand ownership illusion generates mu-ERD in the sensorimotor cortex similar to the one produced during motor imagery BCI. Although, in our experiment no tactile feedback was provided, we postulate that their results are compatible with our findings and suggest that the correlations found in the current experiment between the mu-ERD and P450 with the ownership illusion question may be related by a similar mechanism to the one they describe.…”

Behavioral, Neural, and Computational Principles of Bodily Self-Consciousness

“…Neuroimaging studies (Macaluso and Driver, 2005;Makin et al, 2007;Serino et al, 2011a;Sereno and Huang, 2014) associated these effects with brain regions in human posterior parietal and premotor cortices, hosting bimodal and multimodal neurons, as revealed by earlier neurophysiological work in non-human primates (Duhamel et al, 1998;Graziano et al, 1994;Rizzolatti et al, 1981). Similar regions also process signals involved in self-attribution of the hand (Ehrsson et al, 2004;Tsakiris et al, 2007;Evans and Blanke, 2013) and face (Cardini et al, 2011;Apps et al, 2015).…”

The bodily self: Insights from clinical and experimental research

“…In the ''virtual arm illusion,'' spatial and temporal synchrony is created between the touch applied to the participant's hand (top part of the figure) and the touch observed on the virtual arm (bottom part of the figure: scene shown in the head-mounted display). Reproduced from Evans and Blanke [110]. Shared electrophysiology mechanisms of body ownership and motor imagery.…”