Supplementary eye field encodes option and action value for saccades with variable reward

Area of Science:

• Neuroscience
• Decision Neuroscience
• Oculomotor Research

Background:

• The supplementary eye field (SEF) plays a role in decision-making and action selection.
• Understanding how the SEF processes value and action is crucial for comprehending goal-directed behavior.

Purpose of the Study:

• To investigate how neurons in the SEF represent reward value and saccade direction.
• To determine if SEF neurons encode subjective or expected value.
• To elucidate the temporal dynamics of value and action signal processing in the SEF.

Main Methods:

• Neuronal activity was recorded in the SEF of monkeys performing saccades to targets with variable reward amounts and uncertainty.
• Analysis focused on identifying neuronal representations of saccade direction, reward value, and action value.

Main Results:

• A significant portion of SEF cells (29%) represented anticipated saccade target value, while others (45%) encoded both saccade direction and value (action value).
• SEF neurons exhibited risk-seeking behavior, responding more strongly to uncertain rewards, indicating subjective value representation.
• Option-value signals emerged early (∼120 ms before saccade), followed by action-value and direction signals (∼60 ms later).
• Many SEF neurons (52%) maintained value-related activity just before saccade initiation, unlike typical oculomotor neurons.

Conclusions:

• The SEF is involved in transforming subjective option-value signals into action-value signals.
• SEF neurons guide saccade selection based on value information but may not be directly involved in saccade initiation.
• These findings offer insights into the neural mechanisms underlying value-based decision-making and action selection.