Journal article 520 views
Dissociable mechanisms of speed-accuracy tradeoff during visual perceptual learning are revealed by a hierarchical drift-diffusion model
Jiaxiang Zhang 
,
James B. Rowe
,
James B. Rowe
Frontiers in Neuroscience, Volume: 8
Swansea University Author:
Jiaxiang Zhang
Full text not available from this repository: check for access using links below.
DOI (Published version): 10.3389/fnins.2014.00069
Abstract
Two phenomena are commonly observed in decision-making. First, there is a speed-accuracy tradeoff (SAT) such that decisions are slower and more accurate when instructions emphasize accuracy over speed, and vice versa. Second, decision performance improves with practice, as a task is learnt. The SAT...
| Published in: | Frontiers in Neuroscience |
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| ISSN: | 1662-453X |
| Published: |
Frontiers Media SA
2014
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| Online Access: |
Check full text
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| URI: | https://cronfa.swan.ac.uk/Record/cronfa61340 |
| Abstract: |
Two phenomena are commonly observed in decision-making. First, there is a speed-accuracy tradeoff (SAT) such that decisions are slower and more accurate when instructions emphasize accuracy over speed, and vice versa. Second, decision performance improves with practice, as a task is learnt. The SAT and learning effects have been explained under a well-established evidence-accumulation framework for decision-making, which suggests that evidence supporting each choice is accumulated over time, and a decision is committed to when the accumulated evidence reaches a decision boundary. This framework suggests that changing the decision boundary creates the tradeoff between decision speed and accuracy, while increasing the rate of accumulation leads to more accurate and faster decisions after learning. However, recent studies challenged the view that SAT and learning are associated with changes in distinct, single decision parameters. Further, the influence of speed-accuracy instructions over the course of learning remains largely unknown. Here, we used a hierarchical drift-diffusion model to examine the SAT during learning of a coherent motion discrimination task across multiple training sessions, and a transfer test session. The influence of speed-accuracy instructions was robust over training and generalized across untrained stimulus features. Emphasizing decision accuracy rather than speed was associated with increased boundary separation, drift rate and non-decision time at the beginning of training. However, after training, an emphasis on decision accuracy was only associated with increased boundary separation. In addition, faster and more accurate decisions after learning were due to a gradual decrease in boundary separation and an increase in drift rate. The results suggest that speed-accuracy instructions and learning differentially shape decision-making processes at different time scales. |
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| Keywords: |
speed-accuracy tradeoff, perceptual learning, drift-diffusion model, Bayesian parameter estimation,motion discrimination |
| College: |
Faculty of Science and Engineering |
| Funders: |
This work was supported by Medical Research Council program (MC-A060-5PQ30) and Wellcome Trust (088324). |