A further test of sequential-sampling models that account for payoff effects on response bias in perceptual decision tasks.
Recently, Diederich and Busemeyer (2006) evaluated three hypotheses formulated as particular versions of a sequential-sampling model to account for the effects of payoffs in a perceptual decision task with time constraints. The bound-change hypothesis states that payoffs affect the distance of the starting position of the decision process to each decision bound. The drift-rate-change hypothesis states that payoffs affect the drift rate of the decision process. The two-stage-processing hypothesis assumes two processes, one for processing payoffs and another for processing stimulus information, and that on a given trial, attention switches from one process to the other. The latter hypothesis gave the best account of their data. The present study investigated two questions: (1) Does the experimental setting influence decisions, and consequently affect the fits of the hypotheses? A task was conducted in two experimental settings--either the time limit or the payoff matrix was held constant within a given block of trials, using three different payoff matrices and four different time limits--in order to answer this question. (2) Could it be that participants neglect payoffs on some trials and stimulus information on others? To investigate this idea, a further hypothesis was considered, the mixture-of-processes hypothesis. Like the two-stage-processing hypothesis, it postulates two processes, one for payoffs and another for stimulus information. However, it differs from the previous hypothesis in assuming that on a given trial exactly one of the processes operates, never both. The present design had no effect on choice probability but may have affected choice response times (RTs). Overall, the two-stage-processing hypothesis gave the best account, with respect both to choice probabilities and to observed mean RTs and mean RT patterns within a choice pair.
Diederich
Adele
A
Jacobs University Bremen, Bremen, Germany. a.diederich@jacobs-university.de
D001288:Attention; D002755:Choice Behavior; D003118:Color Perception; D003657:Decision Making; D004193:Discrimination Learning; D030141:Feedback, Psychological; D006801:Humans; D015233:Models, Statistical; D009042:Motivation; D009949:Orientation; D010364:Pattern Recognition, Visual; D011597:Psychomotor Performance; D011601:Psychophysics; D011930:Reaction Time; D012858:Size Perception; D013998:Time Perception