Implicit Sequence Learning Task Research Articles

Exploring brain plasticity in developmental dyslexia through implicit sequence learning.

Developmental dyslexia (DD) is defined as difficulties in learning to read even with normal intelligence and adequate educational guidance. Deficits in implicit sequence learning (ISL) abilities have been reported in children with DD. We investigated brain plasticity in a group of 17 children with DD, compared with 18 typically developing (TD) children, after two sessions of training on a serial reaction time (SRT) task with a 24-h interval. Our outcome measures for the task were: a sequence-specific implicit learning measure (ISL), entailing implicit recognition and learning of sequential associations; and a general visuomotor skill learning measure (GSL). Gray matter volume (GMV) increased, and white matter volume (WMV) decreased from day 1 to day 2 in cerebellar areas regardless of group. A moderating effect of group was found on the correlation between WMV underlying the left precentral gyrus at day 2 and the change in ISL performance, suggesting the use of different underlying learning mechanisms in DD and TD children during the ISL task. Moreover, DD had larger WMV in the posterior thalamic radiation compared with TD, supporting previous reports of atypical development of this structure in DD. Further studies with larger sample sizes are warranted to validate these results.

Time course of learning sequence representations in action imagery practice

Action imagery practice (AIP) is effective to improve motor performance in a variety of tasks, though it is often less effective than action execution practice (AEP). In sequence learning, AIP and AEP result in the acquisition of effector-independent representations. However, it is unresolved whether effector-dependent representations can be acquired in AIP. In the present study, we investigated the acquisition of effector-independent representations and effector-dependent representations in AEP and AIP in an implicit sequence learning task (a visual serial-reaction-time task, involving a twelve-element sequence). Participants performed six sessions, each starting with tests. A practice sequence, a mirror sequence, and a different sequence were tested with the practice and transfer hand. In the first four sessions, after the tests, two groups performed either AIP (N = 50) or AEP (N = 54). Improvement in the different sequence indicated sequence-unspecific learning in both AEP and AIP. Importantly, reaction times of the practice hand became shorter in the practice sequence than in the other sequences, indicating implicit sequence learning in both, AEP and AIP. This effect was stronger in the practice hand than in the transfer hand, indicating effector-dependent sequence representations in both AEP and AIP. However, effector-dependent sequence representations were stronger in AEP than in AIP. No significant differences between groups were observed in the transfer hand, although effector-independent sequence representations were observed in AEP only. In conclusion, AIP promotes not only sequence-unspecific stimulus-response coupling and anticipations of the subsequent stimuli, but also anticipations of the subsequent responses.

Implicit Learning of True and False Belief Sequences.

To investigate whether people can implicitly learn regularities in a social context, we developed a new implicit sequence learning task combining elements from classic false belief and serial reaction time tasks. Participants learned that protagonists were offered flowers at four locations. The protagonists' beliefs concerning the flowers were true or false, depending on their orientation, respectively, toward the scene (so that the flowers could be seen) or away from it. Unbeknown to the participants, there was a fixed belief-related sequence involving three dimensions (identity of the two protagonists, true-false belief orientation held by the protagonists, and flower location as believed by the protagonists). Participants had to indicate as fast as possible where the flowers were located (Experiment 1), or how many flowers were given (Experiment 2) according to the protagonists. Experiment 1 combined perceptual and motor processes (as both the belief-related sequence and motor responses referred to location), whereas Experiment 2 unconfounded the sequence and motor responses, allowing to investigate pure perceptual implicit learning. For reasons of comparison, two non-social conditions were created in Experiment 2 by replacing the protagonists with two non-social objects—colored cameras or shapes. Results revealed significant implicit sequence learning of all belief-related dimensions in Experiment 1, and of true-false belief orientation in Experiment 2, even without a motor confound. Importantly, there were faster reaction times and stronger sequence learning effects in the social than in the non-social conditions. The present findings demonstrate for the first time that people are able to implicitly learn belief-related sequences.

The impact of implicit and explicit suggestions that 'there is nothing to learn' on implicit sequence learning.

We can sometimes efficiently pick up statistical regularities in our environment in the absence of clear intentions or awareness, a process typically referred to as implicit sequence learning. In the current study, we tried to address the question whether suggesting participants that there is nothing to learn can impact this form of learning. If a priori predictions or intentions to learn are important in guiding implicit learning, we reasoned that suggesting participants that there is nothing to learn in a given context should hamper implicit learning. We introduced participants to random contexts that indicated that there was nothing to learn, either implicitly (i.e., by presenting blocks of random trials in "Experiment 1"), or explicitly (i.e., by explicitly instructing them in "Experiment 2"). Next, in a subsequent learning phase, participants performed an implicit sequence learning task. We found that these implicit or explicit suggestions that 'there was nothing to learn' did not influence the emergence of implicit knowledge in the subsequent learning phase. Although these findings seem consistent with simple associative or Hebbian learning accounts of implicit sequence learning (i.e., not steered by predictions), we discuss potential limitations that should inform future studies on the role of a priori predictions in implicit learning.

High Definition Transcranial Direct Current Stimulation Does Not Modulate Implicit Task Sequence Learning and Consolidation

The incidental acquisition of a succession of tasks is termed implicit task sequence learning. Patients with dorsolateral prefrontal cortex (DLPFC) lesions are strongly impaired in this ability. However, recent results of conventional transcranial direct current stimulation (tDCS) above the prefrontal cortex showed no modulation of implicit task sequence learning and consolidation. One explanation for these null findings is that conventional tDCS has non-focal effects on the cortex. Thus, the aim of the present study was to use a focal type of tDCS, namely high definition tDCS (HD-tDCS), to influence implicit task sequence learning and consolidation. Participants received stimulation during implicit task sequence learning and, 24 h later, consolidation was measured. The results showed that sequence learning was present in all conditions and sessions. Furthermore, consolidation was robust. However, both sequence learning and consolidation were not modulated by stimulation. Thus, this study corroborates previous findings by showing that even focal HD-tDCS is not sufficient to modulate implicit task sequence learning and consolidation.

Is procedural memory enhanced in Tourette syndrome? Evidence from a sequence learning task

Procedural memory, which is rooted in the basal ganglia, underlies the learning and processing of numerous automatized motor and cognitive skills, including in language. Not surprisingly, disorders with basal ganglia abnormalities have been found to show impairments of procedural memory. However, brain abnormalities could also lead to atypically enhanced function. Tourette syndrome (TS) is a candidate for enhanced procedural memory, given previous findings of enhanced TS processing of grammar, which likely depends on procedural memory. We comprehensively examined procedural learning, from memory formation to retention, in children with TS and typically developing (TD) children, who performed an implicit sequence learning task over two days. The children with TS showed sequence learning advantages on both days, despite a regression of sequence knowledge overnight to the level of the TD children. This is the first demonstration of procedural learning advantages in any disorder. The findings may further our understanding of procedural memory and its enhancement. The evidence presented here, together with previous findings suggesting enhanced grammar processing in TS, underscore the dependence of language on a system that also subserves visuomotor sequencing.

No effects of transcranial DLPFC stimulation on implicit task sequence learning and consolidation

Neurostimulation of the dorsolateral prefrontal cortex (DLPFC) can modulate performance in cognitive tasks. In a recent study, however, transcranial direct current stimulation (tDCS) of the DLPFC did not affect implicit task sequence learning and consolidation in a paradigm that involved bimanual responses. Because bimanual performance increases the coupling between homologous cortical areas of the hemispheres and left and right DLPFC were stimulated separately the null findings may have been due to the bimanual setup. The aim of the present study was to test the effect of neuro-stimulation on sequence learning in a uni-manual setup. For this purpose two experiments were conducted. In Experiment 1, the DLPFC was stimulated with tDCS. In Experiment 2 the DLPFC was stimulated with transcranial magnetic stimulation (TMS). In both experiments, consolidation was measured 24 hours later. The results showed that sequence learning was present in all conditions and sessions, but it was not influenced by stimulation. Likewise, consolidation of sequence learning was robust across sessions, but it was not influenced by stimulation. These results replicate and extend previous findings. They indicate that established tDCS and TMS protocols on the DLPFC do not influence implicit task sequence learning and consolidation.

A single session of prefrontal cortex transcranial direct current stimulation does not modulate implicit task sequence learning and consolidation

BackgroundTranscranial direct current stimulation (tDCS) is assumed to affect cortical excitability and dependent on the specific stimulation conditions either to increase or decrease learning. ObjectiveThe purpose of this study was to modulate implicit task sequence learning with tDCS. MethodsAs cortico-striatal loops are critically involved in implicit task sequence learning, tDCS was applied above the dorsolateral prefrontal cortex (DLPFC). In Experiment 1, anodal, cathodal, or sham tDCS was applied before the start of the sequence learning task. In Experiment 2, stimulation was applied during the sequence learning task. Consolidation of learning was assessed after 24 h. ResultsThe results of both experiments showed that implicit task sequence learning occurred consistently but it was not modulated by different tDCS conditions. Similarly, consolidation measured after a 24 h-interval including sleep was also not affected by stimulation. ConclusionsThese results indicate that a single session of DLPFC tDCS is not sufficient to modulate implicit task sequence learning. This study adds to the accumulating evidence that tDCS may not be as effective as originally thought.

Task-related functional connectivity of the caudate mediates the association between trait mindfulness and implicit learning in older adults.

Accumulating evidence shows a positive relationship between mindfulness and explicit cognitive functioning, i.e., that which occurs with conscious intent and awareness. However, recent evidence suggests that there may be a negative relationship between mindfulness and implicit types of learning, or those that occur without conscious awareness or intent. Here we examined the neural mechanisms underlying the recently reported negative relationship between dispositional mindfulness and implicit probabilistic sequence learning in both younger and older adults. We tested the hypothesis that the relationship is mediated by communication, or functional connectivity, of brain regions once traditionally considered to be central to dissociable learning systems: the caudate, medial temporal lobe (MTL), and prefrontal cortex (PFC). We first replicated the negative relationship between mindfulness and implicit learning in a sample of healthy older adults (60-90 years old) who completed three event-related runs of an implicit sequence learning task. Then, using a seed-based connectivity approach, we identified task-related connectivity associated with individual differences in both learning and mindfulness. The main finding was that caudate-MTL connectivity (bilaterally) was positively correlated with learning and negatively correlated with mindfulness. Further, the strength of task-related connectivity between these regions mediated the negative relationship between mindfulness and learning. This pattern of results was limited to the older adults. Thus, at least in healthy older adults, the functional communication between two interactive learning-relevant systems can account for the relationship between mindfulness and implicit probabilistic sequence learning.

Characterizing skill acquisition through motor imagery with no prior physical practice.

Motor learning depends upon plasticity in neural networks involved in the planning and execution of movement. Physical practice (PP) is the primary means of motor learning, but it can be augmented with nonphysical forms of practice including motor imagery (MI)-the mental rehearsal of movement. It is unknown if MI alone, without prior PP of a movement, can produce robust learning. Here the authors used an implicit sequence learning task to explore motor learning via MI alone or PP. Participants underwent implicit sequence learning training via MI (n = 31) or PP (n = 33). Posttraining reaction time was faster for implicit versus random sequences for both the MI group (M = 583 ± 84 ms; 632 ± 86 ms, d = 0.59) and PP group (M = 532 ± 73 ms; 589 ± 70 ms, d = 0.80), demonstrating that MI without PP facilitated skill acquisition. Relative to MI alone, PP led to reduced reaction time for both random (d = 0.65) and implicit sequences (d = 0.55) consistent with a nonspecific motor benefit favoring PP over MI. These results have broad implication for theories of MI and support the use of MI as a form of practice to acquire implicit motor skills. (PsycINFO Database Record

Implicit sequence learning in people with Parkinson's disease.

Implicit sequence learning involves learning about dependencies in sequences of events without intent to learn or awareness of what has been learned. Sequence learning is related to striatal dopamine levels, striatal activation, and integrity of white matter connections. People with Parkinson’s disease (PD) have degeneration of dopamine-producing neurons, leading to dopamine deficiency and therefore striatal deficits, and they have difficulties with sequencing, including complex language comprehension and postural stability. Most research on implicit sequence learning in PD has used motor-based tasks. However, because PD presents with motor deficits, it is difficult to assess whether learning itself is impaired in these tasks. The present study used an implicit sequence learning task with a reduced motor component, the Triplets Learning Task (TLT). People with PD and age- and education-matched healthy older adults completed three sessions (each consisting of 10 blocks of 50 trials) of the TLT. Results revealed that the PD group was able to learn the sequence, however, when learning was examined using a Half Blocks analysis (Nemeth et al., 2013), which compared learning in the 1st 25/50 trials of all blocks to that in the 2nd 25/50 trials, the PD group showed significantly less learning than Controls in the 2nd Half Blocks, but not in the 1st. Nemeth et al. (2013) hypothesized that the 1st Half Blocks involve recall and reactivation of the sequence learned, thus reflecting hippocampal-dependent learning, while the 2nd Half Blocks involve proceduralized behavior of learned sequences, reflecting striatal-based learning. The present results suggest that the PD group had intact hippocampal-dependent implicit sequence learning, but impaired striatal-dependent learning. Thus, sequencing deficits in PD are likely due to striatal impairments, but other brain systems, such as the hippocampus, may be able to partially compensate for striatal decline to improve performance.

Implicit task sequence learning in patients with Parkinson's disease, frontal lesions and amnesia: The critical role of fronto–striatal loops

The purpose of this study was to investigate the role of the fronto–striatal system for implicit task sequence learning. We tested performance of patients with compromised functioning of the fronto–striatal loops, that is, patients with Parkinson's disease and patients with lesions in the ventromedial or dorsolateral prefrontal cortex. We also tested amnesic patients with lesions either to the basal forebrain/orbitofrontal cortex or to thalamic/medio-temporal regions. We used a task sequence learning paradigm involving the presentation of a sequence of categorical binary-choice decision tasks. After several blocks of training, the sequence, hidden in the order of tasks, was replaced by a pseudo-random sequence. Learning (i.e., sensitivity to the ordering) was assessed by measuring whether this change disrupted performance. Although all the patients were able to perform the decision tasks quite easily, those with lesions to the fronto–striatal loops (i.e., patients with Parkinson's disease, with lesions in the ventromedial or dorsolateral prefrontal cortex and those amnesic patients with lesions to the basal forebrain/orbitofrontal cortex) did not show any evidence of implicit task sequence learning. In contrast, those amnesic patients with lesions to thalamic/medio-temporal regions showed intact sequence learning. Together, these results indicate that the integrity of the fronto–striatal system is a prerequisite for implicit task sequence learning.

Sleep and health: beyond sleep duration and sleepiness?

Sleep and health: beyond sleep duration and sleepiness?

Implicit task sequence learning with auditory stimuli

We investigated implicit task sequence learning with auditory stimuli. In previous studies only visual stimuli have been used and thus learning may have been due to visuoperceptual learning. Further, we explored the generality of the correlated streams account which holds that correlated streams of information are necessary for implicit sequence learning to occur. We used three classification tasks with auditory stimuli. The presence or absence of a task sequence was orthogonally manipulated with that of a response sequence. Sequence-specific learning was found, but only in the condition with both a task and a response sequence. No learning was found in the conditions with a single task sequence and with a single response sequence. These results show that task–response sequence learning occurs with auditory stimuli and that visuoperceptual learning is not necessary. Moreover, they underscore the importance of correlated streams of information for implicit sequence learning.

"What matters in implicit task sequence learning: Perceptual stimulus features, task sets, or correlated streams of information?" Correction to Weiermann et al. (2010).

"What matters in implicit task sequence learning: Perceptual stimulus features, task sets, or correlated streams of information?" Correction to Weiermann et al. (2010).

Interference between Sentence Processing and Probabilistic Implicit Sequence Learning

BackgroundDuring sentence processing we decode the sequential combination of words, phrases or sentences according to previously learned rules. The computational mechanisms and neural correlates of these rules are still much debated. Other key issue is whether sentence processing solely relies on language-specific mechanisms or is it also governed by domain-general principles.Methodology/Principal FindingsIn the present study, we investigated the relationship between sentence processing and implicit sequence learning in a dual-task paradigm in which the primary task was a non-linguistic task (Alternating Serial Reaction Time Task for measuring probabilistic implicit sequence learning), while the secondary task were a sentence comprehension task relying on syntactic processing. We used two control conditions: a non-linguistic one (math condition) and a linguistic task (word processing task). Here we show that the sentence processing interfered with the probabilistic implicit sequence learning task, while the other two tasks did not produce a similar effect.Conclusions/SignificanceOur findings suggest that operations during sentence processing utilize resources underlying non-domain-specific probabilistic procedural learning. Furthermore, it provides a bridge between two competitive frameworks of language processing. It appears that procedural and statistical models of language are not mutually exclusive, particularly for sentence processing. These results show that the implicit procedural system is engaged in sentence processing, but on a mechanism level, language might still be based on statistical computations.

What matters in implicit task sequence learning: Perceptual stimulus features, task sets, or correlated streams of information?

Implicit task sequence learning may be attributed to learning the order of perceptual stimulus features associated with the task sequence, learning a series of automatic task set activations, or learning an integrated sequence that derives from 2 correlated streams of information. In the present study, our purpose was to distinguish among these 3 possibilities. In 4 separate experiments, we replicated and extended a previous study by Heuer, Schmidtke, and Kleinsorge (2001). The presence or absence of a sequence of tasks, as well as that of a sequence of different task-to-response mappings, was manipulated independently within experiments. Evidence of implicit sequence learning was found only when correlated sequences of tasks and mappings were present. No sequence learning effects were found when only a single task sequence or a single mapping sequence was present, even when the structure of the single sequence was identical to the structure of the integrated sequence of task-mapping combinations. These results suggest that implicit task sequence learning is not dependent on either perceptual learning of stimulus features or automatic task-set activation per se. Rather, it appears to be driven by correlated streams of information.

One ring does not rule them all - Sleep has no critical role in implicit motor sequence learning in young and old adults

Event Abstract Back to Event One ring does not rule them all - Sleep has no critical role in implicit motor sequence learning in young and old adults Karolina Janacsek1*, Zsuzsa Londe2, Michael T. Ullman3, Darlene V. Howard4, James H. Howard Jr5 and Dezso Németh1 1 University of Szeged, Institute of Psychology, Hungary 2 University of Southern California, American Language Institute, United States 3 Georgetown University, Brain and Language Lab, Department of Neuroscience, United States 4 Georgetown University, Department of Psychology, United States 5 The Catholic University of America, Department of Psychology, United States Implicit skill learning underlies not only motor but also cognitive and social skills, and it therefore plays an important role from infancy to old age. The influence of sleep on skill consolidation has been a research topic of increasing interest. In this study we distinguished general skill learning from sequence-specific learning in a probabilistic implicit sequence learning task (Alternating Serial Reaction Time – ASRT Task) in young and elder adults before and after a 12-hour offline interval which did or did not contain sleep (PM-AM and AM-PM groups respectively). The results showed that general skill learning, as assessed via overall RT, improved offline in both the young and older groups, with the young group improving more than the old. However, we found no evidence that this improvement was sleep-dependent, in that there were no differences between the AM-PM and the PM-AM groups. In the case of sequence-specific learning, we did not find offline improvement in either age group for either the AM-PM or PM-AM groups, suggesting that consolidation of this kind of implicit sequence learning is not influenced by sleep. Conference: IBRO International Workshop 2010, Pécs, Hungary, 21 Jan - 23 Jan, 2010. Presentation Type: Poster Presentation Topic: Cognition and behavior Citation: Janacsek K, Londe Z, Ullman MT, Howard DV, Howard Jr JH and Németh D (2010). One ring does not rule them all - Sleep has no critical role in implicit motor sequence learning in young and old adults. Front. Neurosci. Conference Abstract: IBRO International Workshop 2010. doi: 10.3389/conf.fnins.2010.10.00157 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2010; Published Online: 30 Apr 2010. * Correspondence: Karolina Janacsek, University of Szeged, Institute of Psychology, Szeged, Hungary, janacsekkarolina@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Karolina Janacsek Zsuzsa Londe Michael T Ullman Darlene V Howard James H Howard Jr Dezso Németh Google Karolina Janacsek Zsuzsa Londe Michael T Ullman Darlene V Howard James H Howard Jr Dezso Németh Google Scholar Karolina Janacsek Zsuzsa Londe Michael T Ullman Darlene V Howard James H Howard Jr Dezso Németh PubMed Karolina Janacsek Zsuzsa Londe Michael T Ullman Darlene V Howard James H Howard Jr Dezso Németh Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Sleep has no critical role in implicit motor sequence learning in young and old adults

The influence of sleep on motor skill consolidation has been a research topic of increasing interest. In this study, we distinguished general skill learning from sequence-specific learning in a probabilistic implicit sequence learning task (alternating serial reaction time) in young and old adults before and after a 12-h offline interval which did or did not contain sleep (p.m.-a.m. and a.m.-p.m. groups, respectively). The results showed that general skill learning, as assessed via overall reaction time, improved offline in both the young and older groups, with the young group improving more than the old. However, the improvement was not sleep-dependent, in that there was no difference between the a.m.-p.m. and p.m.-a.m. groups. We did not find sequence-specific offline improvement in either age group for the a.m.-either p.m. or p.m.-a.m. groups, suggesting that consolidation of this kind of implicit motor sequence learning may not be influenced by sleep.

The role of the basal ganglia and its cortical connections in sequence learning: Evidence from implicit and explicit sequence learning in Parkinson's disease

Implicit (unconscious/incidental) and explicit (conscious/intentional) learning are considered to have distinct neural substrates. It is proposed that implicit learning is mediated by the basal ganglia (BG), while explicit learning has been linked to the medial temporal lobes (MTL). To test such a dissociation we investigated implicit and explicit sequence learning in Parkinson's disease (PD), a disorder characterized by striatal dysfunction. We studied both implicit and explicit learning of a 12-item sequence of target locations in 13 PD patients and 15 age-matched controls. In the implicit sequence learning task all participants completed 10 blocks of a probabilistic serial reaction time (SRT) task in which they were exposed to the sequence without explicit knowledge of it. Participants also completed between 1 and 10 blocks of an explicit sequence learning task in which the sequence was learned deliberately by trial-and-error. Both implicit and explicit sequence learning were significantly impaired in PD patients compared to controls. The results indicate that, in addition to playing a role in implicit sequence learning, the BG and its frontal projections are also involved in explicit sequence learning.