Multiple decisions about one object involve parallel sensory acquisition but time-multiplexed evidence incorporation

Area of Science:

• Cognitive Neuroscience
• Perception
• Decision-Making

Background:

• The brain processes multiple information streams concurrently.
• Understanding how the brain makes simultaneous decisions about a single object is crucial.

Purpose of the Study:

• To investigate the neural mechanisms underlying dual perceptual decisions about an object's color and motion.
• To determine if decision accuracy and response times are affected by concurrent processing.

Main Methods:

• Utilized a dynamic random dot display to create difficult perceptual decisions.
• Measured decision accuracy and response times for color and motion stimuli.
• Analyzed the temporal dynamics of evidence acquisition for each decision.

Main Results:

• Decision accuracy for one attribute (color or motion) was independent of the other's difficulty.
• Response times indicated that decisions were not made simultaneously.
• Evidence for both stimulus dimensions was acquired in parallel initially, then serially processed.

Conclusions:

• A bottleneck exists, preventing simultaneous updates of multiple decisions.
• A buffer stores evidence samples when decision access is blocked.
• This bottleneck may explain the extended timescales of cognitive decision-making processes.