Decision making under time pressure: An independent test of sequential sampling models

Choice probability and choice response time data from a risk-talking decisi on-making task were compared with predictions made by a sequential sampling model. The behavioral data, consistent with the model, showed that partici pants were less likely to take an action as risk levels increased, and that time pressure did not have a uniform effect on choice probability. Under t ime pressure, participants were more conservative at the lower risk levels but were more prone to take risks at the higher levels of risk. This crosso ver interaction reflected a reduction of the threshold within a single deci sion strategy rather than a switching of decision strategies. Response time data, as predicted by the model, showed that participants took more time t o make decisions at the moderate risk levels and that time pressure reduced response time across all risk levels, but particularly at the those risk l evels that took longer time with no pressure. Finally, response time data w ere used to rule out the hypothesis that time pressure effects could be exp lained by a fast-guess strategy.