Different Forms of Variability Could Explain a Difference Between Human and Rat Decision Making.

Area of Science:

• Cognitive Neuroscience
• Computational Neuroscience
• Animal Behavior

Background:

• Perceptual decision-making exhibits trial-to-trial variability in response time.
• Human accuracy decreases with longer response times, while rat accuracy increases in visual tasks.
• Discrepant findings challenge existing decision-making theories.

Purpose of the Study:

• To unify rodent and primate decision-making results within a single theoretical framework.
• To explain the opposing correlations between accuracy and response time in humans and rats.
• To investigate the role of parameter variability and deterministic biases in decision models.

Main Methods:

• Utilized a bounded drift diffusion model (DDM).
• Simulated decision-making processes with variable parameters.
• Introduced trial-to-trial variability in starting points and drift rates.
• Explored deterministic biases as an alternative explanation.

Main Results:

• The DDM successfully explained both human and rat accuracy-response time patterns.
• Variability in the starting point of the diffusion process replicated rat data.
• Variability in the drift rate replicated human data.
• Deterministic biases also produced similar effects without parameter stochasticity.

Conclusions:

• A single bounded drift diffusion model can account for conserved mammalian decision-making mechanisms.
• Trial-to-trial variability in model parameters (starting point vs. drift rate) explains interspecies differences.
• Deterministic biases offer an alternative mechanism for generating these observed patterns.