Influence of Expected Reward on Temporal Order Judgment

Area of Science:

• Cognitive Neuroscience
• Neuroeconomics
• Computational Neuroscience

Background:

• Perceptual decision-making is influenced by expected rewards from alternative choices.
• The neural basis of reward's influence on decision-making remains unclear, with debate on whether it affects sensory or decision stages.
• Understanding this mechanism is crucial for explaining goal-directed behavior.

Purpose of the Study:

• To investigate whether reward influences perceptual decision-making by modulating sensory processing or later decision-making stages.
• To differentiate between perceptual bias and response bias in the context of reward modulation.
• To explore potential neural mechanisms underlying reward's influence on decision-making.

Main Methods:

• Two experiments with human participants performing a temporal judgment task involving saccades to visual targets.
• Manipulation of expected reward for correct and incorrect responses on a trial-by-trial basis.
• Comparison of reward-induced biases across experiments and simulation using a cortical network model.

Main Results:

• Similar reward biases were observed in both experiments, indicating reward primarily influences later decision-making stages.
• Reward-induced biases were independent of individual sensory sensitivity.
• Cortical network model simulations supported reward-dependent input to the output layer of the decision circuit.

Conclusions:

• Reward primarily modulates later stages of decision-making (response bias) rather than early sensory processing (perceptual bias) in temporal judgment tasks.
• Reward effects appear to be heuristic, modulating decision processes rather than altering sensory perception.
• Findings suggest a neural mechanism where reward influences the output layer of the decision circuit.