Hypermnesia and the Role of Delay between Study and Test

Abstract

Hypermnesia is increased recall across repeated tests in the absence of any further study opportunities. Although over the years many factors have been identified that influence hypermnesia, to date not much is known about the role of delay between study and test for the effect. This study addressed the issue in four experiments. Employing both words and pictures as study material, we compared hypermnesia after shorter delay (3 min or 11.5 min) and longer delay (24 h or 1 week) between study and test. Recall occurred over three successive tests, using both free recall (Experiments 1, 2, and 4) and forced recall testing (Experiment 3). In forced recall tests, subjects are instructed to recall as many items as possible, but if unable to remember all studied items, to fill in the remaining spaces with their best guesses. With free recall testing, hypermnesia increased with delay and the effect was driven mainly by reduced item losses between tests. These results suggest a link between hypermnesia and the testing effect, which shows that demanding retrieval practice, as it happens after longer delay, can improve recall by reducing the forgetting of the practiced items. In contrast, with forced recall testing, hypermnesia decreased with delay and was even absent after longer delay. The findings indicate that recall format can influence hypermnesia and different mechanisms may mediate the effects of repeated testing in the two recall conditions.

Memory consolidation and improvement by synaptic tagging and capture in recurrent neural networks

“…For late intermediate recall, the gain reaches values that are much higher compared to the case without intermediate recall. Hence, additional recall improves the recall quality even further, which is consistent with the experimental findings 55 – 57 .

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“…There are several psychological studies that investigate hypermnesia/improvement by considering the memory strength after multiple recalls 55 – 57 . Therefore, we also investigated the impact of an intermediate recall on the memory dynamics.…”

Memory consolidation and improvement by synaptic tagging and capture in recurrent neural networks

“…In psychological literature, such an increase in recall quality over time is referred to as memory improvement or hypermnesia [26]. It has been found particularly, but not exclusively, in picture memory [26,61,79]. In our simulations and analyses, we found the improvement effect already to occur at the very first recall attempt, while in psychological experiments the effect of improvement has mostly been measured over the course of several recall attempts.…”

“…There are several psychological studies that investigate hypermnesia/improvement by considering the memory strength after multiple recalls [27,61,79]. Therefore, we also investigated the impact of an intermediate recall on the memory dynamics.…”

“…Ideally, to be comparable to our results, there should not be any attempt to recall during the eight hours, which could be hard to manage for the subjects. However, at least trying to avoid intermediate recall would provide some new insights as compared to previous psychological studies that were based on intermediate recall [27,61,79].…”