Neural correlates of visual motion prediction

Abstract

Predicting the trajectories of moving objects in our surroundings is important for many life scenarios, such as driving, walking, reaching, hunting and combat. We determined human subjects' performance and task-related brain activity in a motion trajectory prediction task. The task required spatial and motion working memory as well as the ability to extrapolate motion information in time to predict future object locations. We showed that the neural circuits associated with motion prediction included frontal, parietal and insular cortex, as well as the thalamus and the visual cortex. Interestingly, deactivation of many of these regions seemed to be more closely related to task performance. The differential activity during motion prediction vs. direct observation was also correlated with task performance. The neural networks involved in our visual motion prediction task are significantly different from those that underlie visual motion memory and imagery. Our results set the stage for the examination of the effects of deficiencies in these networks, such as those caused by aging and mental disorders, on visual motion prediction and its consequences on mobility related daily activities.

Figure 1. Task design (“Prediction” trials).

Each trial started with the appearance of the FP. After 0.5 s, a square appeared near the edge of the screen and moved across the screen at a constant direction and speed. An invisible occluder was at the center of the screen (the rectangle with the dashed line), and the square disappeared from view as it encountered the occluder. Subjects were instructed to assume that the square kept moving behind the occluder. After 2 to 4 sec., the FP turned off and five targets appeared. Subjects pressed appropriate buttons to indicate which target was closest to the final position of the square. In “perception” trials, no occluder was present and the square was visible throughout the trial.

Figure 2. Regions of task-related activation and deactivation averaged over all subjects.

A. “Prediction” trials. B. “Perception” trials. The warm colors indicate activation; and the cold colors indicate deactivation. The detailed description of each region is in Table 1.

Figure 3. Contrast images averaged over all subjects.

A. Prediction trials – Perception trials. B. Perception trials – Prediction trials. The detailed description of each region is in Table 2.

Figure 4. Scatter plots of the significant correlation between ROI modulation and error rates in prediction trials for all subjects.

The complete list is in Table 3. Note that, for ROIs that showed task-related deactivation, the correlation is plotted between error rates and the deactivation level. In other words, the larger the number on the x axis, the larger the deactivation.