Mind's eye: Saccade-related evoked potentials support visual encoding in humans.

Area of Science:

• Neuroscience
• Cognitive Science
• Vision Science

Background:

• Active vision relies on discontinuous visual input gated by saccadic eye movements.
• Saccadic modulation of neural activity is a proposed mechanism for perception and memory, but its existence and function in humans are unclear.

Purpose of the Study:

• To investigate the existence and functional role of saccade-related evoked potentials (SREPs) in human visual encoding.
• To determine if SREPs are linked to memory formation and distinguish them from motor-related neural signals.

Main Methods:

• Utilized eye tracking and intracranial local field potentials from epilepsy patients performing visual encoding tasks.
• Developed a saccade-related neural dynamic (SRND) model to analyze pre-saccadic oscillations and SREPs.
• Employed random forest and Shapley value analyses to link neural features to memory performance.

Main Results:

• Observed consistent SREPs across the cerebrum, not attributable to ocular or retinal activity.
• Found that SREP characteristics (latency, magnitude) correlated with successful visual encoding and next-day recognition memory (62.6% accuracy).
• Demonstrated that SREPs are unlikely to be corollary discharge signals for saccade direction, as prediction accuracy was at chance level.

Conclusions:

• Saccade-related evoked potentials (SREPs) represent a neural mechanism of saccadic modulation in humans.
• SREPs play a significant role in visual encoding and are associated with successful long-term memory formation.