The relation between latency and accuracy in the identification of visual stimuli. II. The effects of sequential dependencies

Data from the two experiments described in part I were examined for sequential effects. There was a significant tendency for high-numbered responses to follow high-numbered responses and low-numbered responses to follow low-numbered responses, and for errors to follow errors of the same degree and direction. This is explained in terms of a process comparing each stimulus with its predecessor (H OLLAND and L OCKHEAD, 1968). The increased latency of errors over correct responses was greater when a similar stimulus or response preceded than when a dissimilar one preceded. The accumulator theory (A UDLEY and P IKE, 1965) which was used to explain the results described in part I, is reinterpreted as a process comparing each stimulus with its predecessor. Preceding stimuli which the S judges to be more similar to the succeeding stimulus are assumed to enable a more accurate comparison and thus in effect to make the succeeding stimulus more discriminable. Therefore, as with more discriminable stimuli, the latency of correct responses decreases and that of incorrect responses increases, yielding a greater difference between the two.