Ronald Okada

Memory Retrieval from Long and Short Lists

Reaction time in Sternbergs memory retrieval task with both short and long lists is a bilinear function of list length, changing slope at the limits of memory span. Separate long-term and short-term retrieval processes are implied. An alternative one-process model expressed by a logarithmic function is also considered.

Parallel scanning of physical and category information

In Sternberg’s memory scan paradigm, subjects were required to scan for category membership or physical identity. In Experiment I, the scan rate when checking for either type of relationship at the same time was less than the sum of the scan rates when checking for either relationship separately. In Experiment II, presenting memory sets consisting of items from a single category affected the category scan function but not the physical scan function. The results were interpreted as evidence for the capacity to conduct parallel scans of independent memory encodings when retrieving remembered information.

Part-list recall following part-whole learning

Following five trials of part-list free recall learning and six trials of whole-list free recall learning, Ss were asked to recall the part-list items on two successive trials. Experimental Ss whose whole list contained all of the part-list items recalled more part-list items than did control Ss whose whole list contained none of the part-list items. The data are inconsistent with current notion of subjective organization.

STAZ: interactive software for undergraduate statistics.

STAZ is an interactive computer program that demonstrates statistical concepts, many of which cannot be readily demonstrated using conventional methods. Use of dynamic graphics encourages active engagement with challenging statistical concepts. The program consists of 13 graphical demonstrations, most of which allow for interactive participation by students. A detailed Help file with guided explanations accompanies each demonstration. STAZ is a multiple document interface program that makes full use of Windows features, such as tiling, links, and multitasking. Designed to be used as a supplement for any undergraduate statistics course, STAZ may be used by either instructors in classroom settings or students working independently.

Effect of Reaction-Time Feedback on Subject Performance in the Item-Recognition Task

Two experiments investigated the effect of performance feedback when testing recognition memory for short prememorized lists. Subjects were provided with either response-accuracy or response-latency feedback on a trial-by-trial basis. Payoff in both conditions depended solely upon accuracy performance. Subjects familiarized with their latencies responded faster than subjects given only accuracy feedback. There was no speed-accuracy trade-off. These results are discussed with reference to similar data from the choice reaction-time task. It is concluded that failure to provide subjects with adequate feedback on all aspects of this task is a serious oversight. This oversight is particularly surprising in those designs focusing upon speed.