The reliability of Hebb repetition learning and its association with language and reading in adolescents with intellectual disabilities.

Hebb repetition learning (HRL) refers to neurodevelopmental processes characterised by repeated stimulus exposure without feedback, which result in changes in behaviour and/or responses, e.g., long-term learning of serial order. Here, we investigate effects of HRL on serial order memory. The present research aimed to assess the reliability of new HRL measures and investigate their relationships with language and reading skills (vocabulary, grammar, word reading) in adolescents with intellectual disability (ID). A comparison group of children of similar mental age with typical development (TD) was also assessed. ID and TD groups were tested on HRL tasks, evaluating test-retest and split-half reliability. The relationship between HRL and language and reading was analysed after accounting for the influence of mental age and verbal short-term memory. The HRL tasks displayed moderate test-retest (and split-half) reliability, HRL tasks with different stimuli (verbal, visual) were related, and we identified issues with one method of HRL scoring. The planned regression analyses failed to show relationships between HRL and language/reading skills in both groups when mental age, a very strong predictor, was included. However, further exploratory regression analyses without mental age revealed HRL's predictive capabilities for vocabulary in the ID group and reading in the TD group, results which need further investigation and replication. HRL displays promise as a moderately reliable metric and exhibits varied and interpretable predictive capabilities for language and reading skills across groups.

Hebb repetition learning in adolescents with intellectual disabilities.

BACKGROUND: Hebb repetition learning is a form of long-term serial order learning that can occur when sequences of items in an immediate serial recall task are repeated. Repetition improves performance because of the gradual integration of serial order information from short-term memory into a more stable long-term memory trace. AIMS: The current study assessed whether adolescents with non-specific intellectual disabilities showed Hebb repetition effects, and if their magnitude was equivalent to those of children with typical development, matched for mental age. METHODS: Two immediate serial recall Hebb repetition learning tasks using verbal and visuospatial materials were presented to 47 adolescents with intellectual disabilities (11-15 years) and 47 individually mental age-matched children with typical development (4-10 years). RESULTS: Both groups showed Hebb repetition learning effects of similar magnitude, albeit with some reservations. Evidence for Hebb repetition learning was found for both verbal and visuospatial materials; for our measure of Hebb learning the effects were larger for verbal than visuospatial materials. CONCLUSIONS: The findings suggested that adolescents with intellectual disabilities may show implicit long-term serial-order learning broadly commensurate with mental age level. The benefits of using repetition in educational contexts for adolescents with intellectual disabilities are considered.

Effects of presentation modality and duration on children's strategy use: A study in computational estimation.

Two experiments were run to determine how presentation modality and duration influence children's arithmetic performance and strategy selection. Third and fourth graders were asked to find estimates for two-digit addition problems (e.g., 52 + 39). Children were tested in three conditions: (1) time-unlimited visual, (2) time-limited visual, or (3) time-limited auditory conditions. Moreover, we assessed children's working-memory updating and arithmetic fluency. Children were told which strategy to use on each problem to assess arithmetic performance while executing strategies, in Experiment 1, and were asked to choose the best strategy of three available strategies to assess strategy selection, in Experiment 2. Presentation modality influenced strategy execution (i.e., children were faster and more accurate in problems under visual than auditory conditions) but only in children with low updating abilities. In contrast, presentation modality had no effect on children's strategy selection. Presentation duration had an effect on both strategy execution and strategy selection with time-limited presentation leading to a decline in children's performance. Interestingly, specifically in children with low updating abilities, time-limited presentation led to poorer performance. Hence, efficient updating seemed to compensate for detrimental effects of auditory in comparison to visual and time-limited in comparison to time-unlimited presentation. These findings have important implications for determining conditions under which children execute strategies most efficiently and select the best strategy on each problem most often, as well as for understanding mechanisms underlying strategic behaviour.

Lexical access speed and the development of phonological recoding during immediate serial recall.

A recent Registered Replication Report (RRR) of the development of verbal rehearsal during serial recall (Elliott et al., 2021) revealed that children verbalized at younger ages than previously thought (Flavell et al., 1966), but did not identify sources of individual differences. Here we use mediation analysis to reanalyze data from the 934 children ranging from 5 to 10 years old from the RRR for that purpose. From ages 5 to 7, the time taken for a child to label pictures (i.e. isolated naming speed) predicted the child's spontaneous use of labels during a visually-presented serial reconstruction task, despite no need for spoken responses. For 6- and 7-year-olds, isolated naming speed also predicted recall. The degree to which verbalization mediated the relation between isolated naming speed and recall changed across development. All relations dissipated by age 10. The same general pattern was observed in an exploratory analysis of delayed recall for which greater demands are placed on rehearsal for item maintenance. Overall, our findings suggest that spontaneous phonological recoding during a standard short-term memory task emerges around age 5, increases in efficiency during the early elementary school years, and is sufficiently automatic by age 10 to support immediate serial recall in most children. Moreover, the findings highlight the need to distinguish between phonological recoding and rehearsal in developmental studies of short-term memory.

Individual differences in children's strategy selection in a computational estimation task with two versus three available strategies.

We investigated how children's strategy selection on different problem types was influenced by whether two or three strategies were available in a computational estimation task. Importantly, we examined the influence of individual differences in working memory updating on these effects. Third and fourth graders (N = 725) were asked to indicate the best strategy for two-digit addition problems (e.g., 47 + 24) without calculating estimates. Homogeneous problems (i.e., both unit digits smaller than 5 or larger than 5) and heterogeneous problems (i.e., one operand's unit digit smaller than 5 and the other's unit digit larger than 5) were included. Children completed selection tasks under two conditions: (a) a three-strategy condition, in which they could choose among the rounding-down strategy (i.e., rounding both operands down), the mixed-rounding strategy (i.e., rounding one operand down and the other operand up), and the rounding-up strategy (i.e., rounding both operands up), and (b) a two-strategy condition, in which they could select between the rounding-down strategy and the rounding-up strategy only. As expected, children chose the best available strategy more often under the three-strategy condition than under the two-strategy condition and more often on homogeneous problems than on heterogeneous problems. Importantly, these effects were moderated by children's updating capacities. That is, children with less efficient updating showed worse selection performance on heterogeneous problems than on homogeneous problems under both conditions. In turn, children with more efficient updating showed comparable performance for both problem types under both conditions. These findings have important implications to further our understanding of underlying processes in children's strategy selection in computational estimation.

Effects of working memory updating on children's arithmetic performance and strategy use: A study in computational estimation.

The current study investigated how children's working memory updating processes influence arithmetic performance and strategy use. Large samples of third and fourth graders were asked to find estimates of two-digit addition problems (e.g., 42 + 76). On each problem, children could choose between the rounding-down strategy (i.e., rounding both operands down to the closest decades) or the rounding-up strategy (i.e., rounding both operands up to the closest decades). Four tasks were used to assess updating. Analyses of strategy use revealed that children with more efficient updating showed higher levels of (a) strategy flexibility (i.e., they were less likely to use a single strategy on all or nearly all problems within a test block), (b) strategy adaptivity (i.e., they selected the better strategy overall more often and were more adaptive specifically on homogeneous and rounding-up problems), and (c) strategy performance (i.e., they tended to execute strategies more quickly, especially on homogeneous and larger problems). Finally, updating exerted a more important role for problem type effects in younger children than in older children. These findings have important implications for further understanding how working memory updating processes influence children's arithmetic performance and age-related differences therein.

Do children use different forms of verbal rehearsal in serial picture recall tasks? A multi-method study.

Use of verbal rehearsal is a key issue in memory development. However, we still lack detailed and triangulated information about the early development and the circumstances in which different forms of rehearsal are used. To further understand significant factors that affect children's use of various forms of rehearsal, the present study involving 108 primary school children adopted a multi-method approach. It combined a carefully chosen word length effect method with a self-paced presentation time method to obtain behavioural indicators of verbal rehearsal. In addition, subsequent trial-by-trial self-reports were gathered. Word length effects in recall suggested that phonological recoding (converting images to names - a necessary precursor for rehearsal) took place, with evidence of more rehearsal among children with higher performance levels. According to self-paced presentation times, cumulative rehearsal was the dominant form of rehearsal only for children with higher spans on difficult trials. The combined results of self-paced times and word length effects in recall suggest that "naming" as simple form of rehearsal was dominant for most children. Self-reports were in line with these conclusions. Additionally, children used a mixture of strategies with considerable intra-individual variability, yet strategy use was nevertheless linked to age as well as performance levels.

Strategic verbal rehearsal in adolescents with mild intellectual disabilities: A multi-centre European study.

BACKGROUND: There is a long-held view that verbal short-term memory problems of individuals with intellectual disabilities (ID) might be due to a deficit in verbal rehearsal. However, the evidence is inconclusive and word length effects as indicator of rehearsal have been criticised. AIM & METHOD: The aim of this multi-site European study was to investigate verbal rehearsal in adolescents with mild ID (n=90) and a comparison group of typically developing children matched individually for mental age (MA, n=90). The investigation involved: (1) a word length experiment with non-verbal recall using pointing and (2) 'self-paced' inspection times to infer whether verbal strategies were utilised when memorising a set of pictorial items. RESULTS: The word length effect on recall did not interact with group, suggesting that adolescents with ID and MA comparisons used similar verbal strategies, possibly phonological recoding of picture names. The inspection time data suggested that high span individuals in both groups used verbal labelling or single item rehearsal on more demanding lists, as long named items had longer inspection times. CONCLUSIONS: The findings suggest that verbal strategy use is not specifically impaired in adolescents with mild ID and is mental age appropriate, supporting a developmental perspective.

Phonological short-term memory impairment and the word length effect in children with intellectual disabilities.

There is mounting evidence that children and adolescents with intellectual disabilities (ID) of nonspecific aetiology perform poorer on phonological short-term memory tasks than children matched for mental age indicating a structural deficit in a process contributing to short-term recall of verbal material. One explanation is that children with ID of nonspecific aetiology do not activate subvocal rehearsal to refresh degrading memory traces. However, existing research concerning this explanation is inconclusive since studies focussing on the word length effect (WLE) as indicator of rehearsal have revealed inconsistent results for samples with ID and because in several existing studies, it is unclear whether the WLE was caused by rehearsal or merely appeared during output of the responses. We assumed that in children with ID only output delays produce a small WLE while in typically developing 6- to 8-year-olds rehearsal and output contribute to the WLE. From this assumption we derived several predictions that were tested in an experiment including 34 children with mild or borderline ID and 34 typically developing children matched for mental age (MA). As predicted, results revealed a small but significant WLE for children with ID that was significantly smaller than the WLE in the control group. Additionally, for children with ID, a WLE was not found for the first word of each trial but the effect emerged only in later serial positions. The findings corroborate the notion that in children with ID subvocal rehearsal does not develop in line with their mental age and provide a potential explanation for the inconsistent results on the WLE in children with ID.