Rates of Presentation, Displaced Rehearsal, and Verbal Discrimination Learning

Four experiments were conducted to test the notion that rehearsal in a verbal discrimination learning task is not confined to the feedback interval, i.e., displaced rehearsal. Specifically, it was hypothesized that during early learning trials rehearsal would be restricted to the feedback interval. However, during later trials, once the subject was beyond the point of guessing the correct item, rehearsal could also occur during the anticipation interval. In all four experiments the opportunity for rehearsal was manipulated by presenting factorial combinations of either short or long anticipation and feedback intervals. Contrary to the hypothesis, no consistent differences were noted across trial blocks. However, the evidence did indicate that a long anticipation interval combined with a short feedback interval facilitated learning relative to a short anticipation interval combined with a long feedback interval. A modified version of displaced rehearsal provides a reasonable explanation for this finding if it is assumed that correct recognition is not a prerequisite for displaced rehearsal.

Retroactive and Proactive Inhibition in Young and Elderly Adults Using an Unpaced Modified Free Recall Test

The role of interference as an age-related variable in RI and PI as a function of anticipation interval and transfer paradigm was studied by employing different transfer paradigms (A-B, A-C; A-B, C-B; A-B, C-D), and by varying the anticipation interval (2 sec. or 4 sec.). 60 young ( M = 27.42 yr.) and 60 elderly adults ( M = 68.73 yr.) learned 2 lists of paired adjectives to an 8/8 criterion and then recalled the lists by means of a written modified method of free recall. Significant age differences in RI and PI were found, with the old Ss showing disproportionately more RI under the 2-sec. A-B, A-C high interference condition. Neither anticipation interval nor transfer paradigm contributed to age differences in PI. Results indicated that adult age differences in RI and PI as measured by the unpaced modified free-recall procedure essentially agree with those in RI and PI studies using relearning and paced recall tests.

Cardiac Index of the Orientation Reaction as a Function of Anticipation Interval

A study was conducted to investigate the form of the heart-rate (HR) response in anticipation of a brief visual stimulus and to determine whether the form of the response changed over trials. 14 college undergraduates were exposed to 12 presentations of a visual stimulus which they were asked to identify. Half the Ss were presented with the stimulus every 10 sec., half every 15 sec. HR was recorded for each second during the anticipation intervals. The results indicated that the cardiac anticipatory response in the 10-sec. group was triphasic—a slight deceleration, followed by an acceleration, followed by a deceleration of approximately equal magnitude, and that the response habituated during the last block of four trials. In the 15-sec. interval the anticipatory response was observed to be primarily biphasic (acceleration-deceleration) and still appeared to be in the process of development by Trial 12. The triphasic HR response was interpreted as an index of the cardiac orientation reaction which habituated as a temporal “neuronal model” was formed.