Context-dependent urgency influences speed-accuracy trade-offs in decision-making and movement execution

Area of Science:

• Neuroscience
• Cognitive Science
• Behavioral Economics

Background:

• Speed-accuracy tradeoffs (SATs) are fundamental in decision-making and motor control.
• These tradeoffs are typically studied in isolation, despite natural behaviors requiring integrated adjustments.

Purpose of the Study:

• To investigate shared mechanisms underlying SAT adjustments in both decision-making and actions.
• To determine if a unified signal influences both cognitive and motor aspects of behavior.

Main Methods:

• Two monkeys performed a reach decision task with varying token movement speeds (fast: 50 ms, slow: 150 ms).
• Behavioral data on decision times, accuracy, movement durations, and saccade vigor were recorded.
• A computational model combining sensory evidence with an urgency signal was used to estimate decision criteria.

Main Results:

• Decisions were faster and less accurate in the 'fast' block compared to the 'slow' block.
• Decision accuracy criteria decreased over time within trials, consistent with the model.
• Movement durations and saccade vigor also showed block-dependent decreases over time, mirroring decision criteria.
• Saccade vigor during decision-making was higher in fast blocks, suggesting context-dependent arousal.

Conclusions:

• A shared urgency/vigor signal likely influences SATs in both decision-making and action execution.
• This shared signal may help optimize reward rates by coordinating cognitive and motor processes.
• Context-dependent global arousal may play a role in modulating this shared signal.