Body orientation and perspective influence conscious monitoring of locomotion in a virtual reality setting
Oliver Alan Kannape, Tej Tadi, Olaf Blanke
Poster
Time: 2009-07-02 09:00 AM – 10:30 AM
Last modified: 2009-06-04
Abstract
Recently we reported data on motor contributions to the bodily awareness of the entire body (agency) during locomotion in a virtual reality setting (Kannape et al. IMRF 2008). In this first study, we asked 9 participants to walk towards 4 different target positions while their body movements were tracked via optical motion capture. Movements were mapped onto a virtual body and played back, in real-time, on a projection screen. The body movement and position of the virtual character could systematically be deviated from the participants’ movements by ±5°, ±10°, ±15°, or ±30°. Motor Performance (MP) and Motor Awareness (MA) were measured. Results showed that participants are unaware of angular biases of ~10° despite participants' motor behaviour (significantly deviated walking paths in the direction opposite to the deviation; p<0.001).
In the current study (N=14) we investigated the influence of a) the virtual body’s orientation and b) its walking direction. We further analysed the relationship between MA and MP, with the Motor Awareness Index (MAI), which describes the likelihood of errors in MA with respect to MP. We found a significant orientation x direction interaction for MP, p=0.016 due to best MP when the virtual body’s orientation and walking direction matched those of the participant. MA (point of subjective ambiguity) was higher than in study 1 (13.8°±0.83°), but did not differ across the experimental conditions (all p>0.18). However, analysis of the MAI revealed that participants were more likely to make MA errors in the inverted conditions (p=0.016).
Our findings show that humans track the position and locomotion of their body (and thus the experienced centre of conscious awareness) with a surprisingly low accuracy within a peripersonal space of ~13.8°. This incorrect awareness during goal-directed locomotion and navigation - found under the present experimental conditions - suggests that the generation of full-body locomotion and the building of a conscious experience of it are distinct brain processes.
In the current study (N=14) we investigated the influence of a) the virtual body’s orientation and b) its walking direction. We further analysed the relationship between MA and MP, with the Motor Awareness Index (MAI), which describes the likelihood of errors in MA with respect to MP. We found a significant orientation x direction interaction for MP, p=0.016 due to best MP when the virtual body’s orientation and walking direction matched those of the participant. MA (point of subjective ambiguity) was higher than in study 1 (13.8°±0.83°), but did not differ across the experimental conditions (all p>0.18). However, analysis of the MAI revealed that participants were more likely to make MA errors in the inverted conditions (p=0.016).
Our findings show that humans track the position and locomotion of their body (and thus the experienced centre of conscious awareness) with a surprisingly low accuracy within a peripersonal space of ~13.8°. This incorrect awareness during goal-directed locomotion and navigation - found under the present experimental conditions - suggests that the generation of full-body locomotion and the building of a conscious experience of it are distinct brain processes.