Embodied prosthetic arm affect on stability
This study investigated whether postural sway is affected by the embodied prosthetic and if so, which components of embodiment are influential. For frequent prosthetics users (FUs) postural sway increased when the prosthetic was removed, for infrequent users (IFUs) the opposite was true.
The sensation that a limb is part of your body is regarded as sense of ownership, whilst the sensation that you are creating the movement is considered sense of agency. This distinction can be particularly important for prosthetics use, where an external device (the prosthetic) can become embodied (where the prosthetic belongs to the individual’s body representation) through either or both of these mechanisms. For upper limb amputees this is often demonstrated in peripersonal space which includes the prosthetic length and an over estimation of proprioceptive stump length.
4 FUs and 5 IFUs were assessed using the embodied sense of self-scale. The WII balance board to assess postural sway in 4 different stance conditions (with and without prosthetic, with eyes open and closed).
Interestingly, ownership was not significantly different between the two groups, whilst agency was significantly higher for FUs. A follow up study was conducted to assess the affect of age on the results for postural sway, found that this was comparable to the results for the amputee participants, additionally an external wrist weight was found not to affect none amputee results.
Read an interesting article about embodiment here!
Some people feel naked if they leave the house without make-up, their watch or mobile phone. Do you think this counts as a form of embodiment?
> From: Imaizumi et al., Conscious Cogn 45 (2016) 75-88(Epub ahead of print). All rights reserved to Elsevier Ltd. Click here for the Pubmed summary.