TY - JOUR
T1 - Eye movements and manual interception of ballistic trajectories
T2 - effects of law of motion perturbations and occlusions
AU - Delle Monache, Sergio
AU - Lacquaniti, Francesco
AU - Bosco, Gianfranco
PY - 2014
Y1 - 2014
N2 - Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects’ head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth’s gravity or perturbed with weightlessness (0g) or hypergravity (2g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects’ oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets’ laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets’ laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target’s tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.
AB - Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects’ head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth’s gravity or perturbed with weightlessness (0g) or hypergravity (2g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects’ oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets’ laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets’ laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target’s tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.
KW - Eye movements
KW - Gravity
KW - Internal model
KW - Manual interception
KW - Prediction
UR - http://www.scopus.com/inward/record.url?scp=84922079753&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84922079753&partnerID=8YFLogxK
U2 - 10.1007/s00221-014-4120-9
DO - 10.1007/s00221-014-4120-9
M3 - Article
C2 - 25311389
AN - SCOPUS:84922079753
VL - 233
SP - 359
EP - 374
JO - Experimental Brain Research
JF - Experimental Brain Research
SN - 0014-4819
IS - 2
ER -