Speed–accuracy manipulations and diffusion modeling: Lack of discriminant validity of the manipulation or of the parameter estimates?
- 14 March 2018
- journal article
- research article
- Published by Springer Science and Business Media LLC in Behavior Research Methods
- Vol. 50 (6), 2568-2585
- https://doi.org/10.3758/s13428-018-1034-7
Abstract
The diffusion model (Ratcliff, 1978 ) is a mathematical model theorized to untangle different cognitive processes involved in binary decision tasks. To test the validity of the diffusion model parameters, several experimental validation studies have been conducted. In these studies, the validity of the threshold separation parameter was tested with speed–accuracy manipulations. Typically, this manipulation not only results in the expected effect on the threshold separation parameter but it also impacts nondecision time: Nondecision time is longer in the accuracy than in the speed condition. There are two possible interpretations of the finding: On the one hand, it could indicate that speed versus accuracy instructions really have an impact on the duration of extradecisional processes. On the other hand, the effect on the measure for nondecision time could be spurious—that is, based on a problem in the parameter estimation procedures. In simulation studies—with the parameter sets based on typical values from experimental validation studies—we checked for possible biases in the parameter estimation. Our analyses strongly suggest that the observed pattern (i.e., slower nondecision processes under accuracy instructions) is attributable to a lack of discriminant validity of the manipulation rather than to trade-offs in the parameter estimations.Funding Information
- Deutsche Forschungsgemeinschaft (VO1288/2-2)
This publication has 50 references indexed in Scilit:
- The Optimality of Sensory Processing during the Speed-Accuracy TradeoffJournal of Neuroscience, 2012
- Evaluating the unequal-variance and dual-process explanations of zROC slopes with response time data and the diffusion modelCognitive Psychology, 2012
- Individual differences, aging, and IQ in two-choice tasksCognitive Psychology, 2010
- The simplest complete model of choice response time: Linear ballistic accumulationCognitive Psychology, 2008
- Interpreting ambiguous stimuli: Separating perceptual and judgmental biasesJournal of Experimental Social Psychology, 2008
- A diffusion model account of criterion shifts in the lexical decision taskJournal of Memory and Language, 2008
- A diffusion model analysis of the effects of aging on letter discrimination.Psychology and Aging, 2003
- The effects of aging on reaction time in a signal detection task.Psychology and Aging, 2001
- Mechanisms of speed–accuracy tradeoff: evidence from covert motor processesBiological Psychology, 2000
- A theory of memory retrieval.Psychological Review, 1978