Proactive and reactive accumulation-to-bound processes compete during perceptual decisions.

Area of Science:

• Neuroscience
• Cognitive Science
• Decision-Making Research

Background:

• Standard decision-making models assume responses are solely stimulus-driven upon reaching a threshold.
• These models do not account for informed, proactive responses independent of stimulus timing.

Purpose of the Study:

• To investigate the coexistence of reactive and proactive response generation in perceptual decision-making.
• To propose a novel model explaining the interplay between stimulus-driven evidence accumulation and action initiation.

Main Methods:

• Utilized a free reaction time auditory task in rats.
• Developed a computational model incorporating competing processes for action initiation and evidence accumulation.

Main Results:

• Demonstrated that both reactive and proactive responses occur, indicating decoupled choice selection and motor initiation.
• The proposed model successfully explains premature responses, urgency effects, and reaction time distributions under various stimulus conditions (delayed, advanced, omitted).
• Identified the Action Initiation process as a key mediator of response timing and modulation by factors like satiation and fatigue.

Conclusions:

• Findings fundamentally extend existing evidence accumulation models by introducing a competitive framework for response generation.
• Proactive and reactive processes dynamically interact to determine response initiation in decision-making tasks.
• The study provides new insights into the neural mechanisms underlying flexible and adaptive behavioral responses.