Abstract
Most studies of the neuronal mechanisms of visual perception and cognition utilize tasks that control for the
influence of eye movements. Implicit in this approach is the assumption that the effects of eye movement are
finite and well-characterized. Yet decades of research have demonstrated that the effects of eye movements
on brain activity are dynamic and extend well beyond the time of the physical movement of the eyes. Thus,
experimenters can restrict eye movements for experimental ease, but ultimately a meaningful account of vision
for the translation of laboratory results to a clinical setting must link what we see to how we engage with the
visual world.
Assessing the impact of eye movements on visual processing has been difficult to accomplish because
different types of eye movements naturally interact, but they have been studied in isolation. The standard
approach makes it difficult to scale-up the existing body of knowledge in an ecologically valid way. To address
this knowledge gap, in recent experiments we measured the responsiveness of prefrontal cortical neurons to
different types of eye movements. We discovered populations of prefrontal neurons that respond robustly to
both fast and slow eye movements. These measurements suggest a novel view of visual-motor integration in
prefrontal cortex in which eye movements, like other signals in prefrontal cortex, exhibit mixed selectivity. In
this view, information about where, when, and how to move the eyes is regulated by shared neural circuitry.
The flexibility of this circuitry allows for the precise coordination of visual perception and different types of eye
movements.
The diversity of brain signals present in frontal cortex makes it an ideal testbed for dissecting the neural
circuitry that mediates how and why we move our eyes. We propose experiments that take an eye movement-
centric approach to record from populations of frontal lobe neurons to address longstanding issues in active
vision. Our first specific aim is to record from prefrontal neurons to determine the extent of shared vs.
independent contributions of prefrontal activity to vision and different types of eye movements. Our second
specific aim involves recording in both brain hemispheres simultaneously to determine how the multitude of
potential eye movement commands are resolved to generate a single visual behavior. The final specific aim is
to measure neuronal activity across frontal cortex to determine whether the coordinated timing of activity
across brain regions governs the ability to switch between different types of eye movements. Collectively,
these experiments will use targeted population recordings across three distinct scales of cortical signals to
provide new insights into the fundamental mechanisms that support everyday visual function.