New reflections on agency and body ownership: The moving rubber hand illusion in the mirror

Abstract

No previous study has simultaneously examined body ownership and agency in healthy subjects during mirror self-observation. We used a moving rubber hand illusion to examine how both body ownership and agency are affected by seeing (i) the body moving in a mirror, compared with (ii) directly viewing the moving hand, and (iii) seeing a visually identical hand rotated by 180°. We elicited ownership of the hand using direct visual feedback, finding this effect was further enhanced when looking at the hand in a mirror, whereas rotating the hand 180° abolished ownership. Agency was similarly elicited using direct visual feedback, and equally so in the mirror, but again reduced for the 180° hand. We conclude that the reflected body in a mirror is treated as 'special' in the mind, and distinct from other external objects. This enables bodies and actions viewed in a mirror to be directly related to the self.

The Onset Time of the Ownership Sensation in the Moving Rubber Hand Illusion

“…Studies have also been conducted to investigate whether the illusion can be elicited with movements instead of with passive visuotactile stimulation (Tsakiris et al, 2006; Dummer et al, 2009; Kalckert and Ehrsson, 2012; Braun et al, 2014; Caspar et al, 2015; Jenkinson and Preston, 2015). In the current version of the moving RHI, the finger of a wooden model hand moves synchronously with the participant’s finger, which is hidden from view ( Figure 1 ; Kalckert and Ehrsson, 2012).…”

Extending the Body for Interaction with Reality

“…• Anatomical plausibility: the artificial limb must be in a plausible posture (position and orientation) with respect to the body [9,14,18,30,31,32,34,48,55].…”

The ‘not-so-strange’ body in the mirror: A principal components analysis of direct and mirror self-observation

“…However, studies investigating the effect of mirror viewing on these multisensory body illusions find equivalent results in the mirror compared with direct view (Bertamini, Berselli, Bode, Lawson, & Wong, 2011;Jenkinson & Preston, 2015;Preston, Kuper-Smith, & Ehrsson, 2015) and as such, have suggested that mirror view is no different from a direct Ôfirst personÕ perspective . This line of argument may therefore suggest that viewing the body in a mirror is essentially the same as viewing the body directly (at least in an explicit or subjective sense), and so be less prone to visual illusions arising simply from prolonged self-observation in a mirror.…”

“…We were particularly interested in exploring whether seeing the body in a mirror would result in a subjective experience that was equivalent to seeing the body directly (see Bertamini et al, 2011;Jenkinson & Preston, 2015;Preston et al, 2015), or if mirror observation would produce strange perceptual experiences, like those reported during prolonged self-viewing of the face (Caputo, 2010(Caputo, , 2013aCaputo et al, 2012;Schwarz & Fjeld, 1968). Additionally, we explored whether these experiences related to pre-existing tendencies to: (i) have anxiety about ones appearance (appearance anxiety), (ii) posses body dysmorphic-type motivations for using mirrors, (iii) have unusual dissociative experiences (e.g.…”