Biology subjects

Babin, K.

Publications and source records attributed to Babin, K..

3 recordsLinked to original sources

bioRxiv2026

Reaching movements in virtual reality depend on the seen avatar arm and not just the acting arm

Virtual reality (VR) offers unique opportunities to study behaviour by allowing the visual environment to be manipulated in ways otherwise impossible in the real world. A central theoretical question is how body-related visual information shapes movement control. Given right-handers' greater dexterity with the right arm, perhaps even seeing a right arm vs. a left arm may engage sensorimotor processes associated with more precise motor control. We examined reaching performance while participants used their own right or left arm to move the manipulandum of a KINARM robot to intercept static targets. Participants wore a VR head-mounted display, calibrated to the robot's physical workspace, in which they saw either the right or left arm holding and moving the manipulandum. The 2 x 2 design allowed for independent manipulation of the controlling arm and virtual arm displayed. As expected, reaches were faster and more accurate when controlled by the right arm. More interestingly, performance was also affected by the seen arm. Participants made straighter reaches when they saw a virtual right arm than a left arm, especially for the right controlling arm. These findings show that precise motor control relies not only on the arm that is actually moved and provides proprioceptive feedback, but also on the visual identity of the arm. The ability to modulate performance using visual features in VR opens new theoretical questions and opportunities for applications such as rehabilitation.

neuroscience↗

bioRxiv2026

fNIRS reveals that live social interactions and visual realism influence neural responses

The human face is central to social interactions, supporting the ability to interpret others' mental states using theory of mind (ToM). We examined whether functional near-infrared spectroscopy (fNIRS) would reveal brain-activation differences between live and pre-recorded social conversations in brain regions implicated in ToM. Furthermore, we examined whether activation depended on the visual realism of a social partner - viewed as a human or an animated avatar. By one view, social interactions may be dependent on how natural the social partner appears; by another view, social interactions may depend only upon the attribution of responses to a real human regardless of visual appearance. Neural activation for pre-recorded compared to live interactions was prolonged, consistent with extended cognitive effort. Activation patterns in the right temporoparietal junction differed between interacting with humans versus avatars, along with a stronger preference for looking at the eyes when interacting with a human (vs. avatar), underscoring the social relevance of real faces. Findings highlight the importance of both live interactions and facial realism in shaping social-cognitive processing, a finding with relevance for optimizing online social interactions.

neuroscience↗

bioRxiv2024

Target interception in virtual reality is better for natural versus unnatural trajectory shapes and orientations

Human performance in perceptual and visuomotor tasks is enhanced when stimulus motion follows the laws of gravitational physics, including acceleration consistent with Earths gravity, g. Here we used a manual interception task in virtual reality to investigate the effects of trajectory shape and orientation on interception timing and accuracy. Participants punched to intercept a ball moving along one of four trajectories that varied in shape (parabola or tent) and orientation (upright or inverted). We also varied the location of visual fixation such that trajectories fell entirely within the lower or upper visual field. Reaction times were faster for more natural shapes and orientations, regardless of visual field. Overall accuracy was poorer and movement time was longer for the inverted tent condition than the other three conditions, perhaps because it was imperfectly reminiscent of a bouncing ball. A detailed analysis of spatial errors revealed that interception endpoints were more likely to fall along the path of the final trajectory in upright vs. inverted conditions, suggesting stronger expectations regarding the final trajectory direction for these conditions. Taken together, these results suggest that the naturalness of the shape and orientation of a trajectory contributes to performance in a virtual interception task.

neuroscience↗