B. Espinozavaras et Cs. Watson, EFFECTS OF DECISION CRITERION ON RESPONSE LATENCIES OF BINARY DECISIONS, Perception & psychophysics, 55(2), 1994, pp. 190-203
The effects of decision criterion on response latencies of binary deci
sions were examined. The stimuli comprised two, partly overlapping, ''
normal'' distributions of either two-digit numbers or tonal frequencie
s. Individual stimuli were randomly sampled from the distributions, an
d subjects had to decide from which distribution the stimulus was samp
led. The decision goal was to maximize the expected gain using three d
ifferent payoff matrices. Decision latencies with and without prior kn
owledge of optimal decision criteria were measured. In a control task,
subjects were asked only to label stimuli as being either above or be
low the optimal criteria (without regard for a posteriori probabilitie
s or expected gain). The relation between criterion and latency was ex
amined by means of a trial-by-trial analysis of the stimuli and the re
sponses. Response latency was inversely related both to the distance b
etween the stimulus and the decision criterion and to the probability
of the response elicited by the stimulus. Response latencies showed a
maximum at the criterion in all conditions. These results were obtaine
d with different stimulus modalities (tones or numbers), different dis
criminability levels within the auditory modality, and different decis
ion tasks. It is proposed that the decision criterion is the primary d
eterminant of response latencies of binary decisions.