Modelling the effects of payoff on response bias in a perceptual discrimination task: Threshold bound, drift-rate-change, or two-stage-processing hypothesis

Three hypothesis, hereafter labelled threshold-bound hypothesis, drift-rate-change hypothesis and two-stage-processing hypothesis are proposed to account for data from a perceptual discrimination task in which three different response deadlines were involved and three different payoffs were presented prior to each individual trial. The present research is to show how the three different hypotheses incorporate response biases into a sequential sampling decision process; how payoffs and deadlines affect choice probabilities; and the hypotheses’ predictions of choice times and choice probabilities. The two-stage-processing hypothesis gave the best account, especially for the choice probabilities whereas the drift-rate-change hypothesis had problems predicting choice probabilities as a function of deadlines. Threshold-bound, drift-rate-change, or two-stage-processing hypothesis 3