Initial evidence suggests that the intention to execute a spatially-directed foot-movement can strongly modulate the representation of peri-personal space (PPS), as suggested by a weakened multisensory representation of the space around the initial foot location before movement onset. However, before concluding that PPS is directly modulated by the intention to execute a lower limb movement it is essential to evaluate the role of motor attention.
Purpose: Motor-induced shifts of attention have been consistently observed during the covert preparation of hand movements, as shown by spatially-specific modulations of visual and tactile processing close to the hand and to the movement goal. However, no study to date has investigated whether analogous sensory processing modulations can be found during the covert preparation of goal-directed foot movements. Here, we assess whether attention shifts occur also during the preparation of a lower limb movement and whether attention shifts are directed towards the movement effector, the goal location or both.
Method: We recorded event related brain potentials (ERPs) to task-irrelevant visual probes presented near the cued effector or goal location while participants covertly prepared a lower-limb movement as instructed by a response cues presented at the beginning of each trial. These cues specified the effector as well as the goal location of an upcoming movement.
Results should reveal systematic modulations of early visual components elicited by task-irrelevant probes presented near the cued effector and the cued goal-location. This study helps demonstrating that the covert preparation of a goal-directed foot movement induced shifts of attention able to modulate sensory processing close to movement-relevant locations. Analogously to hand movements, a close link between covert response preparation and attention shifts should be also present for lower limb movements. Motor-induced shifts of attention can potentially play a role in PPS modulations by lower limb movement planning.