The spacing effect in free recall emerges with development

The unique contributions of day and night sleep to infant motor problem solving

The current study sought to tease apart the unique contributions of napping and nighttime sleep to infant learning, specifically in the context of motor problem solving. We challenged 54 walking infants to solve a novel locomotor problem at three time points-training, test, and follow-up the next morning. One group of infants napped during the delay between training and test. Another group did not sleep during the delay. A third group received the test immediately after training with no delay. Only the Nap group's strategy choices continued to improve through the follow-up session, suggesting that daytime sleep has an active role in strengthening otherwise fragile memory. Although group did not affect strategy maintenance, walk experience did, suggesting that task difficulty may shape the impact of sleep on learning. Thus, day sleep and night sleep make independent contributions to the consolidation of motor problem-solving strategies during infancy.

Reply to Sana et al.’s (2022) Commentary on Rest-from-Deliberate-Learning as a Mechanism for the Spacing Effect

Sana and colleagues (2022) have raised a number of challenges regarding the operationalisation of constructs and selection of articles to Chen et al.’s (Educational Psychology Review 33:1499–1522, 2021) suggestion that resting from cognitive activity could possibly allow for working memory recovery and so explain some of the data on the spacing effect. In our response, we indicate that the goal of our proposed framework was to try to resolve some mixed results of the spacing and interleaving effects and offer an alternative explanation for those mixed results, rather than proposing a theory of everything. We acknowledge that there are other important factors, which does not however, provide grounds for rejecting our hypothesis. Additional empirical studies are needed to determine whether rest and its effect on working memory are important when analysing the spacing effect.

Spacing and Interleaving Effects Require Distinct Theoretical Bases: a Systematic Review Testing the Cognitive Load and Discriminative-Contrast Hypotheses

Spaced and interleaved practices have been identified as effective learning strategies which sometimes are conflated as a single strategy and at other times treated as distinct. Learning sessions in which studying information or practicing problems are spaced in time with rest-from-deliberate-learning periods between sessions generally result in better learning outcomes than massed practice without rest-from-deliberate-learning periods. Interleaved practice also consists of spaced sessions, but by interleaving topics rather than having rest-from-deliberate-learning periods. Interleaving is usually contrasted with blocking in which each learning topic is taught in a single block that provides an example of massed practice. The general finding that interleaved practice is more effective for learning than blocked practice is sometimes attributed to spacing. In the current paper, the presence of rest-from-deliberate-learning periods is used to distinguish between spaced and interleaved practice. We suggest that spaced practice is a cognitive load effect that can be explained by working memory resource depletion during cognitive effort with recovery during rest-from-deliberate-learning, while interleaved practice can be explained by the discriminative-contrast hypothesis positing that interleaving assists learners to discriminate between topic areas. A systematic review of the literature provides evidence for this suggestion.

Interference Effects, Age, and the Spacing Benefit

Improving memory is a high priority for many. One strategy that reliably improves long-term memory is spacing of learning. Using a within-subject cued recall task, we compared recall of 50 weakly associated word pairs in older (55–89 years) and younger (18–22 years) adults across 3 different spaced trials with constant temporal gaps but of varying types of interference (related, unrelated, none). Two control conditions were also included (massed- and single-presentation word pairs). We measured recall performance after a brief delay. During training, recall was lowest for the words in the related interference condition with the remaining groups statistically equal, and younger adults showed better overall performance compared with older adults. At test, both groups showed comparable spacing benefits (with no performance differences between interference conditions), and older adults’ performance equaled that of younger adults. It appears that delay, and not type of interference during the delay, was critical to the spacing benefit.

Distributed practice in verbal recall tasks: A review and quantitative synthesis

The authors performed a meta-analysis of the distributed practice effect to illuminate the effects of temporal variables that have been neglected in previous reviews. This review found 839 assessments of distributed practice in 317 experiments located in 184 articles. Effects of spacing (consecutive massed presentations vs. spaced learning episodes) and lag (less spaced vs. more spaced learning episodes) were examined, as were expanding interstudy interval (ISI) effects. Analyses suggest that ISI and retention interval operate jointly to affect final-test retention; specifically, the ISI producing maximal retention increased as retention interval increased. Areas needing future research and theoretical implications are discussed.

The spacing effect in young children's free recall: support for automatic-process explanations

The effect of spacing repetitions on children's free recall was investigated in two experiments. In Experiment 1, both 4-year-old children and 7-year-old children exhibited a spacing effect in free recall, and the magnitude of the effect did not change with age. In Experiment 2, free recall was examined as a function of spacing, age (3 years old vs. 4 years old) and presentation rate (1 vs. 2 vs. 5 sec per stimulus). A spacing effect was obtained that did not differ as a function of age or presentation rate. Of particular interest was the fact that 3-year-olds exhibited a strong spacing effect even when stimuli were presented at a very rapid 1-sec rate. The results support the hypothesis that fundamental memory mechanisms that operate relatively automatically are sufficient to produce a spacing effect in free recall.

The effect of spacing repetitions on the recognition memory of young children and adults

In Experiment 1, preschoolers, first graders, and third graders were presented a list of pictures that included twice-presented items separated by varying numbers of intervening items. Performance on a subsequent recognition test improved as the spacing between repetitions increased, but the effect of spacing did not interact reliably with grade level. In Experiment 2a, we replicated the spaced-repetition effect in young children and found a similar effect in college students. In Experiment 2b, we varied the conditions under which lists were presented to college students and again found a spacing function that was comparable to that of very young children. The results are consistent with the hypothesis that spaced-repetition effects in recognition are produced by fundamental memory mechanisms that are operational at a very early age and which undergo little change with development.