Nonspecific Retroactive Interference in Children and Adults

Factors modulating the effects of waking rest on memory

Study results indicate that moments of unoccupied rest immediately after learning serve an essential cognitive function: memory consolidation. However, there also are findings suggesting that waking rest after learning has similar effects on delayed memory performance as an active wake condition, where participants work on a cognitive distractor task. Based on these studies, we highlight several potentially modulating factors of the so-called resting effect.

The Effects of Acute Exercise on Retroactive Memory Interference

PURPOSE

Retroactive interference involves the disruption of previously encoded information from newly learned information and thus may impair the consolidation of long-term memory. The objective of this study was to evaluate whether acute exercise can attenuate retroactive memory interference.

DESIGN

Three experimental studies were employed. Experiment 1 employed a between-subject randomized control trial (RCT) involving moderate-intensity walking (15 minutes). Experiment 2 employed a between-subject RCT involving high-intensity jogging (15 minutes). Experiment 3 employed a within-subject RCT involving moderate-intensity walking (15 minutes).

SETTING

University setting.

PARTICIPANTS

One hundred twelve young adults.

MEASURES

After exercise, memory interference was evaluated from an episodic word-list memory task, involving the recall of 2 word lists.

RESULTS

The pooled effect size (standard difference in means: -0.35; 95% confidence interval: -0.64 to -0.06) across the 3 experiments was statistically significant (P = .01).

CONCLUSION

We provide suggestive evidence that acute, short-duration exercise may help attenuate a retroactive memory interference effect. Implications of these findings for exercise to improve memory and attenuate memory decay are discussed.

Post-encoding wakeful resting supports the retention of new verbal memories in children aged 13-14 years

Evidence primarily exists in adults that engaging in task-related mental activity after new learning results in increased forgetting of learned information, compared with quietly resting in the minutes that follow learning, where less forgetting is observed. The current study investigated whether the beneficial effect of post-encoding rest can be observed in children aged 13-14 years. Each child (N = 102) encoded two word lists. After the presentation and immediate recall of one word list, children wakefully rested for 10 min (resting condition), after presentation and immediate recall of the other word list, they solved visuo-spatial problems for 10 min (problem-solving condition). Seven days later, a surprise free recall test for the two word lists took place. Our results showed that children retained more words over 7 days in the resting condition than with the problem-solving condition. Post-hoc analyses revealed that the resting effect was a function of the number of words recollected during the immediate recall. Specifically, those children who recalled fewest words (≤ 13/30 words) in the immediate recall showed a significant resting effect. There was no resting effect in those who recalled a mid-range (14-16/30 words) or a high number (>16/30 words) of words. These results provide new insights into the factors that influence memory in children, and suggest that a few minutes of wakeful rest benefits memory, relative to engaging in an ongoing task. Statement of contribution What is already known on this subject? Task-related mental activity after encoding weakens memory retention more than wakeful resting. Beneficial effect of resting after encoding was found primarily in younger and older adults. What does this study add? We investigated children at the age of 13-14 years. 8-min post-encoding wakeful resting supports memory retention over 7 days. Individuals differ in the impact of a brief period of wakeful resting after learning. Only children with lower immediate memory performances profited from wakeful resting.

Brief period of post-encoding wakeful rest supports verbal memory retention in children aged 10–13 years

Evidence exists that a brief period of wakeful rest after learning can support the retention of memories, whereas a period filled with a cognitive task after learning can weaken the retention of memories. The present study in 10–13 year old children investigated whether wakeful resting after encoding is more beneficial for the retention of new verbal information than watching movies, which reflects a common everyday life/learning break activity in children at this age. Children encoded a word list. After immediate recall of this word list, they wakefully rested for 12 min. Next, children encoded another word list. After immediate recall of this word list, they watched animated short movies for 12 min. The order of the delay conditions (rest, movies) was counterbalanced across children. At the end of the experimental session, a surprise free recall test took place. Overall analyses revealed that while memory performance decreased over time in both the resting condition and movies condition, it decreased significantly more in the movies condition. These results indicate that wakeful resting supports the retention of verbal information in children aged 10–13 years.