Experiment induces supernumerary phantom hand

[frameacloud]

Trigger warning: weird, trippy glitches in how brains and bodies work.

In a recent study in Sweden, published in the Journal of Cognitive Neuroscience, an experiment induced supernumerary phantom limb sensations. They investigated it in more detail by conducting 11 experiments on 234 participants. The tactile illusion works like this:

"the participants sat at a table with their right arm behind a screen so that it was not visible to them. The right hand of the volunteers was then touched by the researchers with a small paintbrush, while they imitated the same movement with a different paintbrush up in the air so that it was visible to the subjects. [...] 'most participants, within less than a minute, transfer the sensation of touch to the region of empty space where they see the paintbrush move, and experience an invisible hand in that position. Previous research has shown that non-bodily objects, such as a block of wood, cannot be experienced as one's own hand, so we were extremely surprised to find that the brain can accept an invisible hand as part of the body.'"¹

Brain scans demonstrated that the participants could really feel the invisible hand. "'Taken together, our results show that the sight of a physical hand is remarkably unimportant to the brain for creating the experience of one's physical self,'" Arvid Guterstam [lead author of the research] explained."²

I include this news here because supernumerary phantom limbs are a common experience among therianthropes and otherkin.

- O. Scribner


Source

1. Sarah Glynn, "Non-Amputees Experience Phantom Limb Sensation." 2013-04-11. Medical News Today. http://www.medicalnewstoday.com/articles/259003.php

2. Ibid.

The study in question:

Arvid Guterstam, Giovanni Gentile, and H. Henrik Ehrsson, "The Invisible Hand Illusion: Multisensory Integration Leads to the Embodiment of a Discrete Volume of Empty Space." Journal of Cognitive Neuroscience 2013-04-11 doi:10.1162/jocn_a_00393