Free Recall Shows Similar Reactivation Behavior as Recognition & Cued Recall

TL;DR

This study shows that free recall retrieval times behave similarly to recognition and cued recall, indicating they share the same reactivation mechanism, with implications for understanding short-term memory types.

Contribution

It demonstrates that free recall retrieval dynamics mirror recognition and cued recall, suggesting a common reactivation process across these memory tasks.

Findings

Retrieval time increases linearly with the number of items recalled.

Retrieval time per item depends on recall probability, independent of age and presentation rate.

Maximum retrieval time per item is approximately 7.2 seconds at low recall probability.

Abstract

I find that the total retrieval time in word free recall increases linearly with the total number of items recalled. Measured slopes, the time to retrieve an additional item, vary from 1.4-4.5 seconds per item depending upon presentation rate, subject age and whether there is a delay after list presentation or not. These times to retrieve an additional item obey a second linear relationship as a function of the recall probability averaged over the experiment, explicitly independent of subject age, presentation rate and whether there is a delay after the list presentation or not. This second linear relationship mimics the relationships in recognition and cued recall (Tarnow, 2008) which suggests that free recall retrieval uses the same reactivation mechanism as recognition or cued recall. Extrapolation limits the time to retrieve an additional item to a maximum of 7.2 seconds per item if the probability of recall is near 0%. Earlier upper limits for recognition and cued recall varied with the item type between 0.2 and 1.8 seconds per item (Tarnow, 2008). Implications include that there are only two types of short term memory: working memory and reactivation.