Neural enhancement and attenuation induced by repetitive recall

Using Theory to Drive Intervention Efficacy: The Role of Dose Form in Interventions for Children with DLD

‘Dose form’ is a construct that has evolved over the last number of years and is central to treating childhood language disorders. In this commentary, we present a framework of dose form that includes techniques, procedures, manner of instruction, and intervention context. We present key findings from a systematic review exploring the impact of intervention dose form on oral language outcomes (specifically morphosyntax and vocabulary learning) in children with DLD. We then discuss the hypothesized theoretical mechanisms of action underpinning these findings.

Intrinsic hippocampal functional connectivity underlying rigid memory in children and adolescents with autism spectrum disorder: A case-control study

Atypical learning and memory in early life can promote atypical behaviors in later life. Less relational learning and inflexible retrieval in childhood may enhance restricted and repeated behaviors in patients with autism spectrum disorder. The purpose of this study was to elucidate the mechanisms of atypical memory in children with autism spectrum disorder. We conducted picture–name pair learning and delayed-recognition tests with two groups: one group with high-functioning autism spectrum disorder children (aged 7–16, n = 41) and one group with typically developing children (n = 82) that matched the first group’s age, sex, and IQ. We assessed correlations between successful recognition scores and seed-to-whole-brain resting-state functional connectivity. Although both learning and retrieval performances were comparable between the two groups, we observed slightly lower category learning and significantly fewer memory gains in the autism spectrum disorder group than in the typically developing group. The right canonical anterior hippocampal network was involved in successful memory in youths with typically developing, while other memory systems may be involved in successful memory in youths with autism spectrum disorder. Context-independent and less relational memory processing may be associated with fewer memory gains in autism spectrum disorder. These atypical memory characteristics in autism spectrum disorder may accentuate their inflexible behaviors in some situations.

Practicing Retrieval Facilitates Learning

How do we go about learning new information? This article reviews the importance of practicing retrieval of newly experienced information if one wants to be able to retrieve it again in the future. Specifically, practicing retrieval shortly after learning can slow the forgetting process. This benefit can be seen across various material types, and it seems prevalent in all ages and learner abilities and on all types of test. It can also be used to enhance student learning in a classroom setting. I review theoretical understanding of this phenomenon (sometimes referred to as the testing effect or as retrieval-based learning) and consider directions for future research.

A role for familiarity in supporting the testing effect over time

Endel Tulving (1985) drew a distinction between Remembering and Knowing, spurring a great deal of research on the memorial experiences of recollection and familiarity and their contribution to various phenomena in memory. More recently, studies have used this distinction to situate our understanding of the processes that contribute to the testing effect-or, the benefit of retrieval practice to later memory (see also Tulving, 1967). Using retention intervals of approximately 15 min or less between initial and final testing, several studies have found that initial testing magnifies estimates of recollection but not familiarity, regardless of whether a testing effect is revealed in overall recognition performance (Chan and McDermott, 2007). However, the efficacy of prior testing in enhancing memory has been shown to change over time, as have estimates of recollection and familiarity. Thus, the mechanisms that underlie the quintessential testing effect-one that occurs in overall recognition or recall over longer delays-are still uncertain. To investigate this issue, in two experiments, subjects studied word lists, took 3-letter stem cued-recall tests on half of the studied words, and completed a final recognition test in which estimates of recollection and familiarity were obtained via confidence (Experiment 1) or Remember-Know-New (Experiment 2) judgments. Critically, final recognition tests occurred either immediately, 1 day (Experiment 1 only), or 4 days after initial learning. At all retention intervals and in both methods of estimating recollection and familiarity on the final test (i.e. receiver-operating characteristic and remember-know analyses), initial testing magnified estimates of both recollection and familiarity. These findings suggest that the testing effect can result from changes in both processes and pose issues for theories of the testing effect that consider an exclusive role for recollection.

Effective Use of Auditory Bombardment as a Therapy Adjunct for Children With Developmental Language Disorders

Purpose

Modeling of grammatical forms has been used in conjunction with conversational recast treatment in various forms. This study tests the relative effect of providing bombardment prior to or after recast treatment.

Method

Twenty-eight children with developmental language disorder participated in daily conversational recast treatment for morpheme errors. This treatment was either preceded or followed by a brief period of intensive auditory bombardment. Generalization to untreated lexical contexts was measured throughout the treatment period to assess the degree of learning and how quickly the onset of measurable learning occurred.

Results

There were no significant differences in elicited use of morphemes for the groups of children who received auditory bombardment before or after enhanced conversational recast treatment. However, there was a difference in the number of children who could be considered treatment responders versus nonresponders, favoring those who received auditory bombardment after recast treatment.

Conclusion

A brief period of auditory bombardment is a relatively low cost addition to recast treatment methods, given how little time it takes. There is a small but measurable advantage to following recast treatment with a period of auditory bombardment.

Supplemental Material

https://doi.org/10.23641/asha.5960005.

The role of retrieval mode and retrieval orientation in retrieval practice: insights from comparing recognition memory testing formats and restudying

The effectiveness of retrieval practice for aiding long-term memory, referred to as the testing effect, has been widely demonstrated. However, the specific neurocognitive mechanisms underlying this phenomenon remain unclear. In the present study, we sought to explore the role of pre-retrieval processes at initial testing on later recognition performance by using event-related potentials (ERPs). Subjects studied two lists of words (Chinese characters) and then performed a recognition task or a source memory task, or restudied the word lists. At the end of the experiment, subjects received a final recognition test based on the remember-know paradigm. Behaviorally, initial testing (active retrieval) enhanced memory retention relative to restudying (passive retrieval). The retrieval mode at initial testing was indexed by more positive-going ERPs for unstudied items in the active-retrieval tasks than in passive retrieval from 300 to 900 ms. Follow-up analyses showed that the magnitude of the early ERP retrieval mode effect (300-500 ms) was predictive of the behavioral testing effect later on. In addition, the ERPs for correctly rejected new items during initial testing differed between the two active-retrieval tasks from 500 to 900 ms, and this ERP retrieval orientation effect predicted differential behavioral testing gains between the two active-retrieval conditions. Our findings confirm that initial testing promotes later retrieval relative to restudying, and they further suggest that adopting pre-retrieval processing in the forms of retrieval mode and retrieval orientation might contribute to these memory enhancements.

The effect of recall, reproduction, and restudy on word learning: a pre-registered study

Background

Certain manipulations, such as testing oneself on newly learned word associations (recall), or the act of repeating a word during training (reproduction), can lead to better learning and retention relative to simply providing more exposure to the word (restudy). Such benefit has been observed for written words. Here, we test how these training manipulations affect learning of words presented aurally, when participants are required to produce these novel phonological forms in a recall task.

Methods

Participants (36 English-speaking adults) learned 27 pseudowords, which were paired with 27 unfamiliar pictures. They were given cued recall practice for 9 of the words, reproduction practice for another set of 9 words, and the remaining 9 words were restudied. Participants were tested on their recognition (3-alternative forced choice) and recall (saying the pseudoword in response to a picture) of these items immediately after training, and a week after training. Our hypotheses were that reproduction and restudy practice would lead to better learning immediately after training, but that cued recall practice would lead to better retention in the long term.

Results

In all three conditions, recognition performance was extremely high immediately after training, and a week following training, indicating that participants had acquired associations between the novel pictures and novel words. In addition, recognition and cued recall performance was better immediately after training relative to a week later, confirming that participants forgot some words over time. However, results in the cued recall task did not support our hypotheses. Immediately after training, participants showed an advantage for cued Recall over the Restudy condition, but not over the Reproduce condition. Furthermore, there was no boost for the cued Recall condition over time relative to the other two conditions. Results from a Bayesian analysis also supported this null finding. Nonetheless, we found a clear effect of word length, with shorter words being better learned than longer words, indicating that our method was sufficiently sensitive to detect an impact of condition on learning.

Conclusions

Our primary hypothesis about training conditions conferring specific advantages for production of novel words presented aurally, especially over long intervals, was not supported by this data. Although there may be practical reasons for preferring a particular method for training expressive vocabulary, no difference in effectiveness was detected when presenting words aurally: reproducing, recalling or restudying a word led to the same production accuracy.

Reversing the testing effect by feedback: Behavioral and electrophysiological evidence

The testing effect refers to the finding that retrieval practice of previously studied information enhances its long-term retention more than restudy practice does. Recent work showed that the testing effect can be dramatically reversed when feedback is provided to participants during final recall testing (Storm, Friedman, Murayama, & Bjork, 2014). Following this prior work, in this study, we examined the reversal of the testing effect by investigating oscillatory brain activity during final recall testing. Twenty-six healthy participants learned cue-target word pairs and underwent a practice phase in which half of the items were retrieval practiced and half were restudy practiced. Two days later, two cued recall tests were administered, and immediate feedback was provided to participants in Test 1. Behavioral results replicated the prior work by showing a testing effect in Test 1, but a reversed testing effect in Test 2. Extending the prior work, EEG results revealed a feedback-related effect in alpha/lower-beta and retrieval-related effects in slow and fast theta power, with practice condition modulating the fast theta power effect for items that were not recalled in Test 1. The results indicate that the reversed testing effect can arise without differential strengthening of restudied and retrieval-practiced items via feedback learning. Theoretical implications of the findings, in particular with respect to the distribution-based bifurcation model of testing effects (Kornell, Bjork, & Garcia, 2011), are discussed.

Increased posterior hippocampal volumes in children with lower increase in body mass index: a 3-year longitudinal MRI study

People are generally lean during childhood and show more variability in body sizes and shapes later in life. Cortical development generally correlates with body growth. However, in children cortical growth may be impaired with oversized body growth. Inverse correlations between body mass index (BMI) and brain volumes suggest that lean bodies may be associated with increased cortical volume. To clarify the positive effects of a lean body on a child's cortical development, we used MRI to measure brain structures longitudinally in 107 children and adolescents aged 5-16 years. The relationships between changes in BMI and cortical volumes during 3 years of development were investigated, while controlling for age, gender and intracranial volume changes. Voxel-based morphometry analyses revealed that an increase in the volume of the right posterior medial temporal lobe – including the hippocampus and parahippocampal gyrus – was associated with lower BMI increases. No correlations were observed between higher BMI increases and cortical volumes. Our results suggest that keeping a lean body – or not getting fat – during childhood can induce an increase in regional cortical volume rather than impair growth. This is the first longitudinal study showing positive effects of a lean body on cortical development in children.

Uncovering the neural mechanisms underlying learning from tests

People learn better when re-study opportunities are replaced with tests. While researchers have begun to speculate on why testing is superior to study, few studies have directly examined the neural underpinnings of this effect. In this fMRI study, participants engaged in a study phase to learn arbitrary word pairs, followed by a cued recall test (recall second half of pair when cued with first word of pair), re-study of each pair, and finally another cycle of cued recall tests. Brain activation patterns during the first test (recall) of the studied pairs predicts performance on the second test. Importantly, while subsequent memory analyses of encoding trials also predict later accuracy, the brain regions involved in predicting later memory success are more extensive for activity during retrieval (testing) than during encoding (study). Those additional regions that predict subsequent memory based on their activation at test but not at encoding may be key to understanding the basis of the testing effect.

Neural correlates of testing effects in vocabulary learning

Tests that require memory retrieval strongly improve long-term retention in comparison to continued studying. For example, once learners know the translation of a word, restudy practice, during which they see the word and its translation again, is less effective than testing practice, during which they see only the word and retrieve the translation from memory. In the present functional magnetic resonance imaging (fMRI) study, we investigated the neuro-cognitive mechanisms underlying this striking testing effect. Twenty-six young adults without prior knowledge of Swahili learned the translation of 100 Swahili words and then further practiced the words in an fMRI scanner by restudying or by testing. Recall of the translations on a final memory test after one week was significantly better and faster for tested words than for restudied words. Brain regions that were more active during testing than during restudying included the left inferior frontal gyrus, ventral striatum, and midbrain areas. Increased activity in the left inferior parietal and left middle temporal areas during testing but not during restudying predicted better recall on the final memory test. Together, results suggest that testing may be more beneficial than restudying due to processes related to targeted semantic elaboration and selective strengthening of associations between retrieval cues and relevant responses, and may involve increased effortful cognitive control and modulations of memory through striatal motivation and reward circuits.

Repetition-related reductions in neural activity reveal component processes of mental simulation

In everyday life, people adaptively prepare for the future by simulating dynamic events about impending interactions with people, objects and locations. Previous research has consistently demonstrated that a distributed network of frontal-parietal-temporal brain regions supports this ubiquitous mental activity. Nonetheless, little is known about the manner in which specific regions of this network contribute to component features of future simulation. In two experiments, we used a functional magnetic resonance (fMR)-repetition suppression paradigm to demonstrate that distinct frontal-parietal-temporal regions are sensitive to processing the scenarios or what participants imagined was happening in an event (e.g., medial prefrontal, posterior cingulate, temporal-parietal and middle temporal cortices are sensitive to the scenarios associated with future social events), people (medial prefrontal cortex), objects (inferior frontal and premotor cortices) and locations (posterior cingulate/retrosplenial, parahippocampal and posterior parietal cortices) that typically constitute simulations of personal future events. This pattern of results demonstrates that the neural substrates of these component features of event simulations can be reliably identified in the context of a task that requires participants to simulate complex, everyday future experiences.