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Published on: August 10, 2014
A ballistic model of choice response time
Scott Brown1, Andrew Heathcote
1Department of Cognitive Sciences, University of California, Irvine, CA 92697-5100, USA. scottb@uci.edu
A new ballistic model explains response time (RT) phenomena by incorporating variability in accumulation rate and starting point. This deterministic model successfully fits benchmark data, offering a simpler alternative to stochastic accumulation processes.
Area of Science:
- Cognitive Psychology
- Computational Neuroscience
- Mathematical Psychology
Background:
- Response time (RT) models commonly employ stochastic accumulation processes.
- Accounting for benchmark RT phenomena necessitates including between-trial variability in starting point or accumulation rate.
- Existing linear and nonlinear models address this variability, but often with complexity.
Purpose of the Study:
- To demonstrate that a ballistic (within-trial deterministic) model can account for benchmark RT phenomena.
- To simplify nonlinear accumulation processes by integrating between-trial variability in accumulation rate and starting point.
- To validate the model's efficacy by fitting it to existing empirical data.
Main Methods:
- Developed a simplified ballistic model based on Usher and McClelland's nonlinear accumulation process.
- Incorporated between-trial variability in both the accumulation rate and the starting point.
- Fitted the proposed model to response time data exhibiting benchmark phenomena.
Main Results:
- The ballistic model successfully accounted for benchmark response time phenomena.
- The model provided a good fit to the empirical data of Ratcliff and Rouder (1998).
- The findings suggest a deterministic within-trial process can explain complex RT patterns.
Conclusions:
- A simplified ballistic model with between-trial variability offers a viable alternative to complex stochastic accumulation models for explaining RT phenomena.
- The study highlights the potential of deterministic processes in cognitive modeling.
- The model's success in fitting empirical data supports its explanatory power for decision-making processes.
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