How Prior Knowledge, Gesture Instruction, and Interference After Instruction Interact to Influence Learning of Mathematical Equivalence.

Although children learn more when teachers gesture, it is not clear how gesture supports learning. Here, we sought to investigate the nature of the memory processes that underlie the observed benefits of gesture on lasting learning. We hypothesized that instruction with gesture might create memory representations that are particularly resistant to interference. We investigated this possibility in a classroom study with 402 second- and third-grade children. Participants received classroom-level instruction in mathematical equivalence using videos with or without accompanying gesture. After instruction, children solved problems that were either visually similar to the problems that were taught, and consistent with an operational interpretation of the equal sign (interference), or visually distinct from equivalence problems and without an equal sign (control) in order to assess the role of gesture in resisting interference after learning. Gesture facilitated learning, but the effects of gesture and interference varied depending on type of problem being solved and the strategies that children used to solve problems prior to instruction. Some children benefitted from gesture, while others did not. These findings have implications for understanding the mechanisms underlying the beneficial effect of gesture on mathematical learning, revealing that gesture does not work via a general mechanism like enhancing attention or engagement that would apply to children with all forms of prior knowledge.

Factors influencing sleep-dependent consolidation: Sleep strengths memory based on encoding depth but not repetition.

Sleep consolidates declarative memory after deep but not shallow incidental encoding, but little is known about this form of consolidation. One unexplored area is the extent to which the amount of exposure to incidentally encoded information affects consolidation processes. In two experiments, we manipulated the number of times information was presented. In Experiment 1, participants encoded words either one or three times in a deep or shallow incidental encoding task and completed a surprise recognition test after sleep or wake. Sleep consolidated information after deep encoding after one and three exposures, but not after shallow encoding. In Experiment 2, we explored the relationship between sleep architecture and memory after deep encoding. There was a trend for accuracy to be negatively related to N1 sleep, and reaction time to be negatively related to slow-wave sleep for words encoded once; however, the correlations did not survive corrections for multiple comparisons. These results are discussed with respect to active and passive consolidation processes.

Consolidation without intention: Sleep strengthens veridical and gist representations of information after incidental encoding.

Sleep strengthens declarative memory, but research investigating the effect of sleep on memory for information that is not explicitly studied for a test is sparse. In two experiments, we investigated the effect of sleep on gist-based and veridical representations of incidentally encoded information. Participants rated words from Deese-Roediger-McDermott (DRM) lists in either a deep or shallow encoding task and completed a surprise memory test after either sleep or wake. In Experiment 1, words were presented in lists, in order of descending associativity with the unpresented critical lure. Memory for list words and critical lures in both encoding tasks was stronger after sleep than wake, suggesting that sleep consolidated gist-based memory. In Experiment 2, the same words were presented in a random order across the experiment to minimize gist-based processing. Sleep strengthened veridical memory for list words following deep, but not shallow, encoding and did not affect critical lures. These results suggest sleep consolidates gist and veridical representations of information after incidental encoding, and that sleep-dependent consolidation processes may depend on processes at encoding, such as overlapping context and the strength of veridical memory traces.