Hebb Repetition Learning Research Articles

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 effects in complex and simple span tasks are based on the same learning mechanism.

The Hebb repetition effect shows improvement in serial recall of repeated lists compared to random nonrepeated lists. Previous research using simple span tasks found that the Hebb repetition effect is limited to constant uninterrupted lists, suggesting chunking as the mechanism of list learning. However, the Hebb repetition effect has been found in complex span tasks, which challenges the chunking explanation, as successive list items are separated by distractor processing, possibly interfering with the unified representations. We tested the possibility that Hebb repetition learning arises from chunking in simple span, but from position-item associations in complex span. In a series of five experiments, we found evidence that contradicts that hypothesis. Results show that (a) Hebb repetition learning in a complex span task can be transferred to a simple span task; (b) Hebb repetition learning from a complex span task cannot be transferred to a partially repeated simple span task; (c) partial repetition in a complex span task does not lead to learning; (d) Hebb repetition learning from a simple span task can be transferred to a complex span task; and (e) repeating the distractors in complex span has no impact on the Hebb repetition effect. These results suggest that the mechanism underlying the Hebb repetition effect in simple and complex span tasks is the same and points at the creation of chunks while excluding the distractors from the long-term memory representation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Sequential processing facilitates Hebb repetition learning in visuospatial domains.

Exposure to the same information improves auditory/verbal short-term memory performance, but such improvement is not always observed in visual short-term memory. In this study, we demonstrate that sequential processing makes visuospatial repetition learning efficient in a paradigm that employs a similar design previously used for an auditory/verbal domain. When we presented sets of color patches simultaneously in Experiments 1-4, recall accuracy did not increase with repetition; however, once color patches were presented sequentially in Experiment 5, accuracy did increase rapidly with repetition, even when participants engaged in articulatory suppression. Moreover, these learning dynamics matched those in Experiment 6, which used verbal materials. These findings suggest that (a) sequential focus on each item facilitates a repetition learning effect, indicating a temporal bottleneck is involved early in this process and (b) repetition learning is mechanistically similar across sensory modalities even though these modalities differently specialize in processing spatial or temporal information. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Repetition learning is neither a continuous nor an implicit process

Learning advances through repetition. A classic paradigm for studying this process is the Hebb repetition effect: Immediate serial recall performance improves for lists presented repeatedly as compared to nonrepeated lists. Learning in the Hebb paradigm has been described as a slow but continuous accumulation of long-term memory traces over repetitions [e.g., Page & Norris, Phil. Trans. R. Soc. B 364, 3737-3753 (2009)]. Furthermore, it has been argued that Hebb repetition learning requires no awareness of the repetition, thereby being an instance of implicit learning [e.g., Guérard etal., Mem. Cogn. 39, 1012-1022 (2011); McKelvie, J. Gen. Psychol.114, 75-88 (1987)]. While these assumptions match the data from a group-level perspective, another picture emerges when analyzing data on the individual level. We used a Bayesian hierarchical mixture modeling approach to describe individual learning curves. In two preregistered experiments, using a visual and a verbal Hebb repetition task, we demonstrate that 1) individual learning curves show an abrupt onset followed by rapid growth, with a variable time for the onset of learning across individuals, and that 2) learning onset was preceded by, or coincided with, participants becoming aware of the repetition. These results imply that repetition learning is not implicit and that the appearance of a slow and gradual accumulation of knowledge is an artifact of averaging over individual learning curves.

Hebb repetition learning in adolescents with intellectual disabilities

BackgroundHebb 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. AimsThe 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. MethodsTwo 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). ResultsBoth 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. ConclusionsThe 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.

The developmental neural substrates of Hebb repetition learning and their link with reading ability.

Hebb repetition learning is a fundamental learning mechanism for sequential knowledge, such as language. However, still little is known about its development. This fMRI study examined the developmental neural substrates of Hebb repetition learning and its relation with reading abilities in a group of 49 children aged from 6 to 12 years. In the scanner, the children carried out an immediate serial recall task for syllable sequences of which some sequences were repeated several times over the course of the session (Hebb repetition sequences). The rate of Hebb repetition learning was associated with modulation of activity in the medial temporal lobe. Importantly, for the age range studied here, learning‐related medial temporal lobe modulation was independent of the age of the children. Furthermore, we observed an association between regular and irregular word reading abilities and the neural substrates of Hebb repetition learning. This study suggests that the functional neural substrates of Hebb repetition learning do not undergo further maturational changes in school age children, possibly because they are sustained by implicit sequential learning mechanisms which are considered to be fully developed by that age. Importantly, the neural substrates of Hebb learning remain significant determinants of children's learning abilities, such as reading.

Determining the developmental requirements for hebb repetition learning in young children: Grouping, short-term memory, and their interaction.

The Hebb repetition paradigm has recently attracted attention as a measure of serial order learning, which underlies word-form learning abilities. Although children are good vocabulary learners, it is surprising that previous Hebb learning studies with young children show rather weak Hebb effects. In this study, we conducted two experiments to identify developmental factors that drive an increase of the size of the Hebb effect in young children. Motivated by evidence from adult work, we focused on an ability to group a sequence into consistent subsequences and on phonological short-term memory (STM) capacity. In Experiment 1 (N = 98), it was shown that 3- to 5-year-old children with high phonological STM capacity showed a Hebb effect, particularly in the later experimental trials. In Experiment 2 (N = 97), temporal grouping of the sequences in 2-2 subsequences further encouraged children with high phonological STM capacity to show the Hebb effect even in the earlier experimental trials and children with low STM capacity to show a trend toward a Hebb effect in the later trials. Moreover, across Experiments 1 and 2 we found robust evidence of transfer of the Hebb effect to recall of new sequences that partially overlapped in item-by-item pairings with the Hebb sequence, indicating that children use consistent grouping strategies when learning above-span Hebb sequences. These findings indicate that phonological STM, grouping consistency, and their interaction are developmental requirements for the Hebb effect to emerge. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

The effects of Hebb repetition learning and temporal grouping in immediate serial recall of spatial location.

The Hebb repetition effect is a phenomenon in which a repeated presentation of the same list increases the performance in immediate serial recall. This provided the theoretical basis for a core assumption of the Atkinson and Shiffrin model regarding information transfer from short-term memory to long-term memory. The Hebb repetition effect was originally reported for the verbal domain, but subsequent studies found similar phenomena using visuospatial paradigms, for example, in serial-order memory for dot locations. The present study examined in two experiments the effects of presentation timing of nine spatial locations on Hebb repetition learning. In Experiment 1, the Hebb repetition effects were observed for spatial locations with constant timing presentation as well as temporal grouping presentation. In the latter condition, all lists were presented with the same temporal structure, that is, temporal pauses were inserted after the third and sixth serial positions. This manipulation led to a better recall performance in comparison with the constant presentation, but did not interact with the repetition. In Experiment 2, the Hebb list was presented with a different temporal structure in every repetition in the random-grouping condition. Although this manipulation is known to eliminate or weaken the Hebb effect in the verbal domain, we observed stable repetition effects in this experiment. This suggests that there might be some domain-specific mechanisms in Hebb repetition learning. These results may facilitate the development of theories of the relationship between short-term and long-term memory.

Is the Hebb repetition task a reliable measure of individual differences in sequence learning?

The Hebb repetition task, an operationalization of long-term sequence learning through repetition, is the focus of renewed interest, as it is taken to provide a laboratory analogue for naturalistic vocabulary acquisition. Indeed, recent studies have consistently related performance in the Hebb repetition task with a range of linguistic (dis)abilities. However, despite the growing interest in the Hebb repetition effect as a theoretical construct, no previous research has ever tested whether the task used to assess Hebb learning offers a stable and reliable measure of individual performance in sequence learning. Since reliability is a necessary condition to predictive validity, in the present work, we tested whether individual ability in visual verbal Hebb repetition learning displays basic test-retest reliability. In a first experiment, Hebrew-English bilinguals performed two verbal Hebb tasks, one with English and one with Hebrew consonant letters. They were retested on the same Hebb tasks after a period of about 6 months. Overall, serial recall performance proved to be a stable and reliable capacity of an individual. By contrast, the test-retest reliability of individual learning performance in our Hebb task was close to zero. A second experiment with French speakers replicated these results and demonstrated that the concurrent learning of two repeated Hebb sequences within the same task minimally improves the reliability scores. Taken together, our results raise concerns regarding the usefulness of at least some current Hebb learning tasks in predicting linguistic (dis)abilities. The theoretical implications are discussed.

Language learning in the adult brain: disrupting the dorsolateral prefrontal cortex facilitates word-form learning

Adults do not learn languages as easily as children do. It has been hypothesized that the late-developing prefrontal cortex that supports executive functions competes with procedural learning mechanisms that are important for language learning. To address this hypothesis, we tested whether a temporary neural disruption of the left Dorsolateral Prefrontal Cortex (DLPFC) can improve implicit, procedural learning of word-forms in adults. Young adults were presented with repeating audio-visual sequences of syllables for immediate serial recall in a Hebb repetition learning task that simulates word-form learning. Inhibitory theta-burst Transcranial Magnetic Stimulation was applied to the left DLPFC or to the control site before the Hebb task. The DLPFC-disrupted group showed enhanced learning of the novel phonological sequences relative to the control group. Moreover, learning was negatively correlated with executive functions that rely on the DLPFC in the control group, but not in the DLPFC-disrupted group. The results support the hypothesis that a mature prefrontal cortex competes with implicit learning of word-forms. The findings provide new insight into the competition between brain mechanisms that contribute to language learning in the adult brain.

Hebb repetition effects for non-verbal visual sequences: determinants of sequence acquisition

ABSTRACTWe report four experiments premised upon the work of Horton et al. [(2008). Hebb repetition effects in visual memory: The roles of verbal rehearsal and distinctiveness. Quarterly Journal of Experimental Psychology, 61(12), 1769–1777] and Page et al. [(2013). Repetition-spacing and item-overlap effects in the Hebb repetition task. Journal of Memory and Language, 69(4), 506–526], and explore conditions under which the visual Hebb repetition effect is observed. Experiment 1 showed that repetition learning is evident when the items comprising the non-repeated (filler) sequences and the repeated (Hebb) sequences are different (no-overlap). However, learning is abolished when the filler and Hebb sequences comprise the same items (full-overlap). Learning of the repeated sequence persisted when repetition spacing was increased to six trials (Experiment 2), consistent with that shown for verbal stimuli (Page et al., 2013). In Experiment 3, it was shown that learning for the repeated sequence is accentuated when the output motor response at test is also repeated for the Hebb sequence, but only under conditions of no-overlap. In Experiment 4, repetition spacing was re-examined with a repeated motor output response (a closer methodological analogue to Page et al., 2013). Under these conditions, the gradient of Hebb repetition learning for six trial repetition intervals was markedly similar to that for three trial intervals. These findings further support the universality of the Hebb repetition effect across memory and are discussed in terms of evidence for amodality within-sequence memory.

Position-element frequency learning is dissociable from Hebb repetition learning

Abstract Position-element association has been extensively investigated as a mechanism for serial order memory and has been widely implemented in models of short-term memory. This study examined whether and how the position-element association is learned as a form of long-term knowledge dissociated from other forms of knowledge such as sequence knowledge acquired in the Hebb list repetition paradigm. Laboratory learning experiments demonstrated that repeated exposure to a specific position-element association facilitated subsequent recall of the position-element association with experimental control of other aspects of to-be-learned statistical structure of the artificial phonotactics. The experiments also demonstrated that the positional frequency learning was more gradual than Hebb list learning, suggesting a dissociation of the two forms of learning. Functional roles of these two forms of learning were discussed.

Tactile order memory: evidence for sequence learning phenomena found with other stimulus types

ABSTRACTWe examine serial order memory for sequences of tactile stimuli and investigate whether established characteristics of order memory, namely serial position effects, error distributions, and Hebb repetition learning, are observed with tactile memory. Visually obscured participants received six tactile stimulations: one to each of six fingers. At test, participants lifted the six fingers in the order of stimulation. For every third trial participants received the same order of stimulation (i.e. the Hebb sequence). Serial recall accuracy produced the canonical bowed serial position function found for immediate serial recall. In addition, recall for the Hebb sequence improved relative to the filler sequences, providing the first demonstration of the Hebb repetition effect with tactile stimuli. Analysis of errors revealed close similarities to that reported with verbal and visual stimuli. This experiment further generalises established features of order memory to tactile memory, supporting the utilisation of an analogous order memory mechanism across stimuli.

The involvement of long-term serial-order memory in reading development: A longitudinal study

Recent findings suggest that Hebb repetition learning—a paradigmatic example of long-term serial-order learning—is impaired in adults with dyslexia. The current study further investigated the link between serial-order learning and reading using a longitudinal developmental design. With this aim, verbal and visual Hebb repetition learning performance and reading skills were assessed in 96 Dutch-speaking children who we followed from first through second grade of primary school. We observed a positive association between order learning capacities and reading ability as well as weaker Hebb learning performance in early readers with poor reading skills even at the onset of reading instruction. Hebb learning further predicted individual differences in later (nonword) reading skills. Finally, Hebb learning was shown to explain a significant part of the variance in reading performance above and beyond phonological awareness. These findings highlight the role of serial-order memory in reading ability.

Can Chunk Size Differences Explain Developmental Changes in Lexical Learning?

In three experiments, we investigated Hebb repetition learning (HRL) differences between children and adults, as a function of the type of item (lexical vs. sub-lexical) and the level of item-overlap between sequences. In a first experiment, it was shown that when non-repeating and repeating (Hebb) sequences of words were all permutations of the same words, HRL was slower than when the sequences shared no words. This item-overlap effect was observed in both children and adults. In a second experiment, we used syllable sequences and we observed reduced HRL due to item-overlap only in children. The findings are explained within a chunking account of the HRL effect on the basis of which we hypothesize that children, compared with adults, chunk syllable sequences in smaller units. By hypothesis, small chunks are more prone to interference from anagram representations included in the filler sequences, potentially explaining the item-overlap effect in children. This hypothesis was tested in a third experiment with adults where we experimentally manipulated the chunk size by embedding pauses in the syllable sequences. Interestingly, we showed that imposing a small chunk size caused adults to show the same behavioral effects as those observed in children. Departing from the analogy between verbal HRL and lexical development, the results are discussed in light of the less-is-more hypothesis of age-related differences in language acquisition.

Serial-order learning impairment and hypersensitivity-to-interference in dyscalculia

In the context of heterogeneity, the different profiles of dyscalculia are still hypothetical. This study aims to link features of mathematical difficulties to certain potential etiologies. First, we wanted to test the hypothesis of a serial-order learning deficit in adults with dyscalculia. For this purpose we used a Hebb repetition learning task. Second, we wanted to explore a recent hypothesis according to which hypersensitivity-to-interference hampers the storage of arithmetic facts and leads to a particular profile of dyscalculia. We therefore used interfering and non-interfering repeated sequences in the Hebb paradigm. A final test was used to assess the memory trace of the non-interfering sequence and the capacity to manipulate it. In line with our predictions, we observed that people with dyscalculia who show good conceptual knowledge in mathematics but impaired arithmetic fluency suffer from increased sensitivity-to-interference compared to controls. Secondly, people with dyscalculia who show a deficit in a global mathematical test suffer from a serial-order learning deficit characterized by a slow learning and a quick degradation of the memory trace of the repeated sequence. A serial-order learning impairment could be one of the explanations for a basic numerical deficit, since it is necessary for the number-word sequence acquisition. Among the different profiles of dyscalculia, this study provides new evidence and refinement for two particular profiles.

Linking memory and language: Evidence for a serial-order learning impairment in dyslexia

The present study investigated long-term serial-order learning impairments, operationalized as reduced Hebb repetition learning (HRL), in people with dyslexia. In a first multi-session experiment, we investigated both the persistence of a serial-order learning impairment as well as the long-term retention of serial-order representations, both in a group of Dutch-speaking adults with developmental dyslexia and in a matched control group. In a second experiment, we relied on the assumption that HRL mimics naturalistic word-form acquisition and we investigated the lexicalization of novel word-forms acquired through HRL. First, our results demonstrate that adults with dyslexia are fundamentally impaired in the long-term acquisition of serial-order information. Second, dyslexic and control participants show comparable retention of the long-term serial-order representations in memory over a period of 1 month. Third, the data suggest weaker lexicalization of newly acquired word-forms in the dyslexic group. We discuss the integration of these findings into current theoretical views of dyslexia.

No solid empirical evidence for the SOLID (serial order learning impairment) hypothesis of dyslexia.

This article reports on 2 studies that attempted to replicate the findings of a study by Szmalec, Loncke, Page, and Duyck (2011) on Hebb repetition learning in dyslexic individuals, from which these authors concluded that dyslexics suffer from a deficit in long-term learning of serial order information. In 2 experiments, 1 on adolescents (N = 59) and 1 on children (N = 57), no empirical evidence was obtained for impaired Hebb learning in dyslexics, whether the same data-analytical procedure as Szmalec et al. was used or whether some methodological improvements were applied (e.g., using a more sensitive index of Hebb learning, and equating groups on filler performance with state trace analysis). In an additional state trace analysis, aggregating data over participants, it was shown that performance on the repeated Hebb sequences was almost perfectly predictable from performance on the nonrepeated sequences (fillers). The implications of these findings are outlined for the current discussion on the mechanisms for encoding immediate serial recall and long-term sequence learning and for computational models attempting to simulate these mechanisms.

The development of long-term lexical representations through Hebb repetition learning

This study clarifies the involvement of short- and long-term memory in novel word-form learning, using the Hebb repetition paradigm. In Experiment 1, participants recalled sequences of visually presented syllables (e.g., la-va-bu-sa-fa-ra-re-si-di), with one particular (Hebb) sequence repeated on every third trial. Crucially, these Hebb sequences contained three orthographic nonword neighbors of existing Dutch base-words (e.g., lavabu – lavabo [kitchen sink]). Twenty-four hours later, the same participants performed two auditory lexicalization tests involving the actual Dutch base-words (e.g., lavabo, safari, residu). Both tests yielded slower reaction times for these Dutch base-words compared with matched control words, which reflects lexical competition between the base-words and the Hebb sequences, therefore demonstrating lexical engagement of the Hebb sequences. In Experiment 2, we subsequently used the Hebb paradigm as an analogue of word-form learning, in order to investigate whether the creation of novel lexical memories requires sleep. Whereas earlier findings indicate that overnight sleep plays a crucial role in lexical consolidation, the current results show that Hebb learning of phonological sequences creates novel word-forms representations in the mental lexicon by the mere passage of time, with sleep playing no necessary role.

Order or disorder? Impaired Hebb learning in dyslexia.

The present study offers an integrative account proposing that dyslexia and its various associated cognitive impairments reflect an underlying deficit in the long-term learning of serial-order information, here operationalized as Hebb repetition learning. In nondyslexic individuals, improved immediate serial recall is typically observed when one particular sequence of items is repeated across an experimental session, a phenomenon known as the Hebb repetition effect. Starting from the critical observation that individuals with dyslexia seem to be selectively impaired in cognitive tasks that involve processing of serial order, the present study is the first to test and confirm the hypothesis that the Hebb repetition effect is affected in dyslexia, even for nonverbal modalities. We present a theoretical framework in which the Hebb repetition effect is assumed to be a laboratory analogue of naturalistic word learning, on the basis of which we argue that dyslexia is characterized by an impairment of serial-order learning that affects language learning and processing.