Individual Differences Link Sensory Processing and Motor Control

What is it about?

Due to the organization of our visual system, with high acuity in the center of the visual field, and a large periphery with lower resolution, we need to constantly move our eyes. Therefore research on eye movements led to great advances in our understanding of sensorimotor processing and human behavior. However, in academic research studies often have focused only individual types of eye movements and measured them in isolation. Most research was performed either on saccades (quick jumps of the gaze) or pursuit eye movements (smooth rotations to follow moving objects). In addition, those eye movements were mostly also measured with respect to different sensory information: saccades with static stimuli, pursuit with dynamic targets. Here, we leveraged interindividual differences across a carefully balanced combination of different tasks. We observed two main results: (1) The isolated previous research missed critical links in the control of oculomotor behavior. We observed correlations in eye movement behavior across tasks, but only when compared with the same sensory information (e.g., pursuit accuracy and accuracy of saccades to moving targets). (2) Within the same task, the coordination of saccadic and pursuit eye movements was tailored to the strengths of the individual: observers with more accurate saccades to moving targets rely on them more to catch up with moving targets.

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Photo by Soroush Karimi on Unsplash

Photo by Soroush Karimi on Unsplash

Why is it important?

Our results have profound implications for the theoretical understanding of sensorimotor processing for oculomotor control. They necessitate a reevaluation of previous data used to map brain circuits for saccadic and pursuit eye movements measured with different types of relevant sensory information. Additionally, they underscore the importance of moving beyond average observations to embrace individual differences as a rich source of information. These individual differences not only reveal the strengths and weaknesses of observers. When combined across different tasks, they allow insights about why observers behave differently in a given task.