Fig 1.
Experimental setup and procedure.
A) Virtual environment. The subject was placed 2 meters apart from the virtual mannequin and saw him from the back. B) Set-up. The subject wore a head-mounted display, held controllers in his/her hands, had trackers on the chest and feet, and had electrodes placed on the feet, hands, and back. C) The electrical stimulation could be either synchronous (left) to the visual stimulus or asynchronous (right). D) Experimental conditions and outcomes. Every row represents a different condition (first column). The second and third columns show the visual and tactile stimulation respectively, for each condition. The fourth column shows the outcome measurements. C-FBI = classical FBI; T-FBI = TENS FBI; TS-4L = TENS on 4 limbs somatotopic; TS-1L = TENS on 1 limb somatotopic; TNS-1L = TENS on 1 limb non-somatotopic.
Fig 2.
Results of the calibration procedure.
For each stimulated location (back trunk, wrists, and ankles in column), the following information is reported for the low (light blue) and high (dark blue) intensity: A) electrodes placement; B) Area of perceived location; C) Covered area in percentage; D) Intensity of the perceived sensation; E) Intensity in loco; F) Stimulation charge used; G) Sensation type reported. Significant results are reported when p<0.05. The error bars represent the SEM.
Fig 3.
Results of experimental conditions (Classical-FBI (C-FBI), TENS-FBI (T-FBI), TENS-Somatotopic 4 Limbs (TS-4L)).
Each panel is relative to a different condition: A) C-FBI, B) T-FBI, C) TS4L. For each condition, the following information is reported for the synchronous (light color) and asynchronous (dark color) alternative: location of the visuo-tactile stimulation, Questionnaires results (embodiment, vividness, prevalence, and body image), PPS results, and MIT results. *Significant results are reported when p<0.05. The error bars represent the SEM. C = classical FBI; T = TENS FBI; T4S = TENS on 4 limbs somatotopic.
Fig 4.
Results of experimental conditions (TS-1L, TNS-1L).
Each panel is relative to a different condition: A) TS-1L, B) TNS-1L. For each condition, the following information is reported for the synchronous (light color) and asynchronous (dark color) alternative: location of the visuo-tactile stimulation, Questionnaires results (embodiment, vividness, prevalence, and body image), PPS results, and MIT results. Significant results are reported when p<0.05. The error bars represent the SEM. TS-1L = TENS on 1 limb somatotopic: TNS-1L = TENS on 1 limb non-somatotopic.