The distribution of latencies constrains theories of decision time: A test of the random-walk model using numeric comparison

Abstract

The random-walk model for decision accurately predicts both mean reaction time and response accuracy as a function of signal strength and response criterion. Although few have examined the changes, the theory also predicts changes in the shape of the distribution of latencies. In a digit-comparison task, we used numeric distance to manipulate signal strength, and we used speed versus accuracy instructions to manipulate response criterion. Random-walk theory correctly predicted changes in the shape of the distribution of response times.