Contrast sensitivity reveals an oculomotor strategy for temporally encoding space

Area of Science:

• Neuroscience
• Vision Science
• Computational Neuroscience

Background:

• The contrast sensitivity function (CSF) is key to visual performance but its neural basis is debated.
• Existing models often overlook the impact of naturalistic eye movements on visual processing.
• Discrepancies exist between primate retinal neuron sensitivity and psychophysical CSF measurements.

Purpose of the Study:

• To investigate how continuous eye movements influence the contrast sensitivity function.
• To reconcile the known response characteristics of retinal ganglion cells with human CSF measurements.
• To explore the integration of perception and action in spatial vision.

Main Methods:

• Utilized psychophysical measurements under natural viewing conditions with continuous eye tracking.
• Modeled the transformation of spatial visual input into temporal retinal signals due to eye movements.
• Compared model predictions with experimental data on human CSF and retinal neuron responses.

Main Results:

• Eye movements create temporal modulations on the retina, acting as a crucial processing step.
• This dynamic retinal processing reconciles the spatial sensitivities of early visual neurons with observed human CSF.
• The findings hold true across a broad range of stimulus conditions.

Conclusions:

• Visual perception is not solely based on low-level sensory processing but involves a dynamic interplay with motor control.
• Eye movements are integral to how the visual system encodes spatial information, working synergistically with retinal neuronal properties.
• This highlights a fundamental link between perception and action in visual processing.