Altered visual feedback from an embodied avatar unconsciously influences movement amplitude and muscle activity

Evidence suggests that the sense of the position of our body parts can be surreptitiously deceived, for instance through illusory visual inputs. However, whether altered visual feedback during limb movement can induce substantial unconscious motor and muscular adjustments is not known. To address this question, we covertly manipulated virtual body movements in immersive virtual reality. Participants were instructed to flex their elbow to 90° while tensing an elastic band, as their virtual arm reproduced the same, a reduced (75°), or an amplified (105°) movement. We recorded muscle activity using electromyography, and assessed body ownership, agency and proprioception of the arm. Our results not only show that participants compensated for the avatar’s manipulated arm movement while being completely unaware of it, but also that it is possible to induce unconscious motor adaptations requiring significant changes in muscular activity. Altered visual feedback through body ownership illusions can influence motor performance in a process that bypasses awareness

Developing attentional control in naturalistic dynamic road crossing situations

In the last 20 years, there has been increasing interest in studying visual attentional processes under more natural conditions. In the present study, we propose to determine the critical age at which children show similar to adult performance and attentional control in a visually guided task; in a naturalistic dynamic and socially relevant context: road crossing. We monitored visual exploration and crossing decisions in adults and children aged between 5 and 15 while they watched road trafc videos containing a range of trafc densities with or without pedestrians. 5–10 year old (y/o) children showed less systematic gaze patterns. More specifcally, adults and 11–15y/o children look mainly at the vehicles’ appearing point, which is an optimal location to sample diagnostic information for the task. In contrast, 5–10y/os look more at socially relevant stimuli and attend to moving vehicles further down the trajectory when the trafc density is high. Critically, 5-10y/o children also make an increased number of crossing decisions compared to 11–15y/os and adults. Our fndings reveal a critical shift around 10y/o in attentional control and crossing decisions in a road crossing task