Early Trajectory Prediction in Elite Athletes

Abstract

Cerebellar plasticity is a critical mechanism for optimal feedback control. While Purkinje cell activity of the oculomotor vermis predicts eye movement speed and direction, more lateral areas of the cerebellum may play a role in more complex tasks, including decision-making. It is still under question how this motor-cognitive functional dichotomy between medial and lateral areas of the cerebellum plays a role in optimal feedback control. Here we show that elite athletes subjected to a trajectory prediction, go/no-go task manifest superior subsecond trajectory prediction accompanied by optimal eye movements and changes in cognitive load dynamics. Moreover, while interacting with the cerebral cortex, both the medial and lateral cerebellar networks are prominently activated during the fast feedback stage of the task, regardless of whether or not a motor response was required for the correct response. Our results show that cortico-cerebellar interactions are widespread during dynamic feedback and that experience can result in superior task-specific decision skills.

Keywords: Baseball; Cerebellum; Decision-making; Elite athletes; Optimal feedback control; Psychophysics; Pupillary response; Trajectory prediction; fMRI.

Fig. 1

Trajectory prediction task. A fixation cross appeared with a variable duration (390 ms, 890 ms, or 1900 ms), followed by either a fast (385 ms), medium (485 ms), or slow (585 ms) moving stimulus to one of eight final locations, within (green dotted lines; go trials) or outside the target square (red dotted lines; no-go trials). Fixation duration and stimulus speed and trajectory were pseudo-randomly intermixed. A screen touch (and hold) in go trials (hit) and no-touch in no-go trials (correct rejection) resulted in a correct response (green check). A red X appeared after an incorrect response: screen touch during no-go trials (false alarm) or no screen touch during go trials (miss). Each subject performed three blocks of 80 trials on the behavioral task

Fig. 2

Performance. a Overall group average performance over 3 blocks of 80 trials. Subjects improved from block 1 to block 2 and block 1 to block 3. Experts performed significantly better than controls on block 3. b Experts perform better on average during the shortest fixation duration and at the fastest flight times. c Experts do better than controls as flight speed decreases by increasing hit rate with a higher D′ score (inset, F fast, M medium, S slow). d–f When all blocks are compiled and broken down by fixation duration and flight time, experts perform better at the short fixation duration of the fast (d) and medium (e) flight times, but not the slow. (*P < .05; **P < .01) (N = 10/group). Numbers represent means and SEM

Fig. 3

fMRI. The main effect of fast responding is shown in a and b. Fast responding is associated with medial and lateral cerebellum. When contrasting BOLD response during fast vs. medium stimuli, across combined hits and correct rejections, differential activity was associated with medial cerebellum (vermis), right lateral cerebellum (crus areas), and left inferior parietal lobe (and Table 1). c BOLD response differences of hit trials between medium and fast flight speed. Cerebellar vermis and right cerebellar cortex (area I–VII, crus I) showed a large significant cluster (Zmax = 3.81; x = 6, y = − 54, z = − 12). Images were thresholded at z > 2.3 cluster corrected at P = .01; only the vermis and right cerebellum exceeded the significance threshold. d BOLD response differences of correct rejections between fast and medium flight speed in six large clusters including cerebellar vermis, right cerebellar cortex (areas I–VII, crus I) (Zmax = 4.19); left putamen, left frontal operculum (Zmax = 4.1); left and right temporo-occipital cortex, inferior parietal lobule (Zmax = 4.22 and 3.96); bilateral superior parietal gyrus, intraparietal sulcus (Zmax = 4.07); and middle frontal gyrus (Zmax = 4.25) (N = 6)

Fig. 4

Pupillary responses. Dashed line indicates stimulus onset. a Subject pupil diameter increased progressively but did not differ between groups at either baseline, end of fixation time, or end of flight time. b During trials with the short fixation, experts reached peak pupil dilation earlier than controls on the fast and medium but not slow flight speeds. c Pupil dilation slope during ball flight on trials with the short fixation and fast speed: consistent with peak latencies, expert pupil diameter enlarged less abruptly during flight time. d During trials with the long fixation, experts reached peak pupil dilation later than controls at all flight speeds. e–g Hit—correct go trials/all go trials; miss—incorrect go trials/all go trials; CR—correct rejections: correct no-go trials/all no-go trials; FA—false alarms: incorrect no-go trials/all no-go trials. e Experts showed larger dilations during false alarms relative to controls. f The slope of pupil dilation across the whole trial (fixation plus flight time) was different when comparing hits to misses and hits to correct rejections. g When considering the fixation intervals only, the slope of pupil dilation depended on the response subjects chose at the end of the trial. (N = 9/group)

Fig. 5

Eye movements. a Expert mean gaze-stimulus distance (GSD) was shorter at the fast flight speed and increased as flight speed decreased, while control mean GSD decreased as flight time decreased, showing an interaction between group and flight speed. b Tracking measures (see methods) showed a significantly larger percentage of the trial tracked by controls during the fastest flight times. We also found the mean percent of the trial tracked increased as stimulus speed decreased from the fast to medium and the fast to slow flight speed (N = 10/group)

Fig. 6

Summary and temporal dynamics. a Upper panel: temporal dynamics of a 90-mph professional baseball pitch. b Group averages of psychophysical responses at the short preparation and fast stimulus speed trials including significant differences in stimulus tracking (arrow length), gaze to stimulus distance (arrow thickness), and peak pupil dilation (transparent bars). Saccade onset, hand movements, and screen touch reaction times did not differ between groups