Selective learning enabled by intention to learn in sequence learning

This study investigated whether a target sequence that people intend to learn is learned selectively when it is interleaved with another (non-target) sequence. Three experiments used a serial reaction time task in which different spatial and color stimuli occurred alternately. Each of the two interleaved sequences had structural regularity. Participants in an intentional learning group were instructed to learn the target (spatial) sequence whereas those in an incidental learning group were not. In Experiments 1 and 2 spatial and color sequences were correlated. Results showed that the intentional group learned the spatial sequence better than the incidental group and learned it independently of the color sequence, whereas the incidental group learned the two sequences as a combined sequence. In Experiment 3 the sequences were uncorrelated. Results showed that the intentional group was no longer superior in learning the spatial sequence. Findings indicate that the intention to learn a target sequence enables selective learning of it only when it is correlated with a non-target sequence.     

Concurrent learning of temporal and spatial sequences

In a serial reaction time task, stimulus events simultaneously defined spatial and temporal sequences. Responses were based on the spatial dimension. The temporal sequence was incidental to the task, defined by the response-to-stimulus intervals in Experiment 1 and stimulus onset asynchronies in Experiment 2. The two sequences were either of equal length and correlated or of unequal length. In both experiments, spatial learning occurred regardless of sequence length condition. In contrast, temporal learning occurred only in the correlated condition. These results suggest that timing is an integrated part of action representations and that incidental learning for a temporal pattern does not occur independently from the action. Interestingly, sequence learning was enhanced in the correlated condition, reflecting the integration of spatial-temporal information.     

Sequential learning in non-human primates

Sequential learning plays a role in a variety of common tasks, such as human language processing, animal communication, and the learning of action sequences. In this article, we investigate sequential learning in non-human primates from a comparative perspective, focusing on three areas: the learning of arbitrary, fixed sequences; statistical learning; and the learning of hierarchical structure. Although primates exhibit many similarities to humans in their performance on sequence learning tasks, there are also important differences. Crucially, non-human primates appear to be limited in their ability to learn and represent the hierarchical structure of sequences. We consider the evolutionary implications of these differences and suggest that limitations in sequential learning may help explain why non-human primates lack human-like language.     

The implicit learning of metrical and nonmetrical temporal patterns

Implicit learning (IL) occurs unintentionally. IL of temporal patterns has received minimal attention, and results are mixed regarding whether IL of temporal patterns occurs in the absence of a concurrent ordinal pattern. Two experiments examined the IL of temporal patterns and the conditions under which IL is exhibited. Experiment 1 examined whether uncertainty of the upcoming stimulus identity obscures learning. Based on probabilistic uncertainty, it was hypothesized that stimulus-detection tasks are more sensitive to temporal learning than multiple-alternative forced-choice tasks because of response uncertainty in the latter. Results demonstrated IL of metrical patterns in the stimulus-detection but not the multiple-alternative task. Experiment 2 investigated whether properties of rhythm (i.e., meter) benefit IL using the stimulus-detection task. The metric binding hypothesis states that metrical frameworks guide attention to periodic points in time. Based on the metric binding hypothesis, it was hypothesized that metrical patterns are learned faster than nonmetrical patterns. Results demonstrated learning of metrical and nonmetrical patterns but metrical patterns were not learned more readily than nonmetrical patterns. However, abstraction of a metrical framework was still evident in the metrical condition. The present study shows IL of auditory temporal patterns in the absence of an ordinal pattern.     

Age-Related Differences in Implicit Learning of Non-Spatial Sequential Patterns

This experiment investigated whether there are age differences in implicit learning of non-spatially arranged sequential patterns. We tested 12 young and 12 old participants for five sessions each in a non-spatial alternating serial reaction time (ASRT) task, in which predictable pattern events alternated with random, unpredictable ones. People of both ages were able to learn the sequence, but older people showed less pattern sensitivity than younger ones. Neither group was able to exhibit declarative knowledge of the pattern or to discriminate between pattern and random sequences on a recognition test, suggesting that the learning was indeed implicit. These findings indicate that the age deficits previously observed in the learning of spatial sequences are not due solely to age-related deficits in visuo-spatial attention or control of eye movements, but rather reflect a more general deficit in the ability to learn subtle sequential regularities.     

Re-examining the role of context in implicit sequence learning

Implicit sequence learning typically develops gradually, is often expressed quite rigidly, and is heavily reliant on contextual features. Recently we reported results pointing to the role of context-specific processes in the acquisition and expression of implicit sequence knowledge (D’Angelo, Milliken, Jiménez, & Lupiáñez, 2013). Here we examined further the role of context in learning of first-order conditional sequences, and whether context also plays a role in learning second-order conditional structures. Across five experiments we show that the role of context in first-order conditional sequences may not be as clear as we had previously reported, while at the same time we find evidence for the role of context in learning second-order conditional sequences. Together the results suggest that temporal context may be sufficient to learn complementary first-order conditional sequences, but that additional contextual information is necessary to concurrently learn higher-order sequential structures.     

Tracking simple and complex sequences

We address issues of synchronization to rhythms of musical complexity. In two experiments, synchronization to simple and more complex rhythmic sequences was investigated. Experiment 1 examined responses to phase and tempo perturbations within simple, structurally isochronous sequences, presented at different base rates. Experiment 2 investigated responses to similar perturbations embedded within more complex, metrically structured sequences; participants were explicitly instructed to synchronize at different metrical levels (i.e., tap at different rates to the same rhythmic patterns) on different trials. We found evidence that (1) the intrinsic tapping frequency adapts in response to temporal perturbations in both simple (isochronous) and complex (metrically structured) rhythms, (2) people can synchronize with unpredictable, metrically structured rhythms at different metrical levels, with qualitatively different patterns of synchronization seen at higher versus lower levels of metrical structure, and (3) synchronization at each tapping level reflects information from other metrical levels. The latter finding provides evidence for a dynamic and flexible internal representation of the sequence's metrical structure.     

Adaptive memory: longevity and learning intentionality of the animacy effect

The animacy effect—the finding that animates are better remembered than inanimates—is proving to be a robust empirical phenomenon. Considering the adaptiveness of the animate advantage, one might expect it to remain after long retention intervals and also to be present irrespectively of an intention to learn. The present study explores these two aspects. Different groups of participants learned (intentional learning) or rated the pleasantness (incidental learning) of animate and inanimate words; memory was tested immediately or after a 48?h delay. A significant animacy effect was obtained after both retention intervals and in both learning conditions. Two significant interactions revealed a larger animacy effect, as well as a larger effect of the retention interval, when learning was incidental. Our findings reinforce the robustness of the animacy effect and provide some insight into possible proximate mechanisms of the effect.     

Motor sequence learning performance in Parkinson's disease patients depends on the stage of disease

It is still unclear, whether patients with Parkinson's disease (PD) are impaired in the incidental learning of different motor sequences in short succession, although such a deficit might greatly impact their daily life. The aim of this study was thus to clarify the relation between disease parameters of PD and incidental motor learning of two different sequences in short succession. Results revealed that the PD patients were able to acquire two sequences in short succession but needed more time than healthy subjects. However, both the severity of axial manifestations, as assessed on a subsection of the Unified Parkinson's Disease Rating Scale III (UPDRS III) and the Hoehn and Yahr score, and the levodopa-equivalent dose (LED) were negatively correlated with the sequence learning performance. These findings indicate that, although PD patients are able to learn two sequences in short succession, they need more time and their overall sequence learning performance is strongly correlated with the stage of disease.     

时间节律的内隐学习及其特征:来自双维度SRT的证据

本文引入双维度SRT方法,以研究时间节律的内隐学习。在第一个实验中,时间节律的内隐学习得到了证明,双维度SRT方法的信度和效果也得到初步验证;实验二则从整体和局部启动角度比较了节律内隐学习和字母序列内隐学习的差异。两个实验得出结论:(1)节律信息可以被内隐地学习到;(2)节律内隐学习和字母序列内隐学习的显露时机不同,前者更加滞后;(3)两者的机制也不同,前者更倾向于以整体方式进行学习。     

Offline improvement occurs for temporal stability but not accuracy following practice of integer and non-integer rhythms

Procedural learning benefits from memory processes occurring outside practice resulting in offline learning. Offline gains have been demonstrated almost exclusively for the ordinal structure of sequential motor tasks. Many skills also demand that the correct serial order of events be appropriately timed. Evidence indicates that the temporal aspect of a procedural skill can be encoded independent of serial order knowledge and governed by at least two distinct neural circuits. The present experiment determined if (a) offline gains emerge for temporal learning, and (b) if such gains occur for timing supervised by distinct timing systems. Participants experienced 216 practice trials of a 7-key press sequence that involved integer- or non-integer timing rhythms. Twenty-four hours after training 30 test trials were administered. Results revealed robust offline enhancement for timing performance of the non-integer based temporal sequences. This improvement was localized to stabilization of the required relative but not absolute time profiles. The neural circuitry central to supporting the performance of non-integer timing sequences is also a principal constituent of what is described as the "cognitive" timing system. Timing governed by this system appears most susceptible to offline gains via consolidation.     

Distinctiveness revisited: Unpredictable temporal isolation does not benefit short-term serial recall of heard or seen events

The notion of a link between time and memory is intuitively appealing and forms the core assumption of temporal distinctiveness models. Distinctiveness models predict that items that are temporally isolated from their neighbors at presentation should be recalled better than items that are temporally crowded. By contrast, event-based theories consider time to be incidental to the processes that govern memory, and such theories would not imply a temporal isolation advantage unless participants engaged in a consolidation process (e.g., rehearsal or selective encoding) that exploited the temporal structure of the list. In this report, we examine two studies that assessed the effect of temporal distinctiveness on memory, using auditory (Experiment 1) and auditory and visual (Experiment 2) presentation with unpredictably varying interitem intervals. The results show that with unpredictable intervals temporal isolation does not benefit memory, regardless of presentation modality.     

Learning Orthographic Structure With Sequential Generative Neural Networks

Learning the structure of event sequences is a ubiquitous problem in cognition and particularly in language. One possible solution is to learn a probabilistic generative model of sequences that allows making predictions about upcoming events. Though appealing from a neurobiological standpoint, this approach is typically not pursued in connectionist modeling. Here, we investigated a sequential version of the restricted Boltzmann machine (RBM), a stochastic recurrent neural network that extracts high‐order structure from sensory data through unsupervised generative learning and can encode contextual information in the form of internal, distributed representations. We assessed whether this type of network can extract the orthographic structure of English monosyllables by learning a generative model of the letter sequences forming a word training corpus. We show that the network learned an accurate probabilistic model of English graphotactics, which can be used to make predictions about the letter following a given context as well as to autonomously generate high‐quality pseudowords. The model was compared to an extended version of simple recurrent networks, augmented with a stochastic process that allows autonomous generation of sequences, and to non‐connectionist probabilistic models (n‐grams and hidden Markov models). We conclude that sequential RBMs and stochastic simple recurrent networks are promising candidates for modeling cognition in the temporal domain.     

Incidental task sequence learning: perceptual rather than conceptual?

In four experiments we investigated whether incidental task sequence learning occurs when no instructional task cues are available (i.e. with univalent stimuli). We manipulated task sequence by presenting three simple binary-choice tasks (colour, form or letter case decisions) in regular repeated or random order. Participants were required to use the same two response keys for each of the tasks. We manipulated response sequence by ordering the stimuli so as to produce either a regular or a random order of left versus right-hand key presses. When sequencing in both, or either, separate stream (i.e. task sequence and/or response sequence) was changed to random, only those participants who had processed both sequences together showed evidence of sequence learning in terms of significant response time disruption (Experiments 1-3). This effect disappeared when the sequences were uncorrelated (Experiment 4). The results indicate that only the correlated integration of task sequence and response sequence produced a reliable incidental learning effect. As this effect depends on the predictable ordering of stimulus categories, it suggests that task sequence learning is perceptual rather than conceptual in nature.     

Oculomotor and manual indexes of incidental and intentional spatial sequence learning during middle childhood and adolescence

The goal of this study was to examine incidental and intentional spatial sequence learning during middle childhood and adolescence. We tested four age groups (8-10 years, 11-13 years, 14-17 years, and young adults [18+ years]) on a serial reaction time task and used manual and oculomotor measures to examine incidental sequence learning. Participants were also administered a trial block in which they were explicitly instructed to learn a sequence. Replicating our previous study with adults, oculomotor anticipations and response times showed learning effects similar to those in the manual modality. There were few age-related differences in the sequence learning indexes during incidental learning, but intentional learning yielded differences on all indexes. Results indicate that the search for regularities and the ability to learn a sequence rapidly under incidental conditions are mature by 8 to 10 years of age. In contrast, the ability to learn a sequence intentionally, which requires cognitive resources and strategies, continues to develop through adolescence.     

语境线索在留学生阅读伴随词汇学习中的作用：来自眼动的证据

为探讨语境线索在留学生伴随性词汇学习中的作用,本研究选择不同汉语水平的外国留学生作为被试,操纵了语境线索的强弱,使用眼动仪记录被试的词汇学习过程。结果发现：被试在强语境线索下的词汇学习效果显著高于弱语境线索;随着学习次数的增加,强语境线索下目标词注视时间的下降幅度显著大于弱语境线索,高汉语水平被试目标词注视时间的下降幅度显著大于低汉语水平被试。结果表明：无论留学生汉语水平如何,语境线索促进了他们阅读时的伴随性词汇学习,且学习次数越多,语境线索的促进作用越大。     

The effect of old age on supra-span learning of visuo-spatial sequences under incidental and intentional encoding instructions

Recent findings [Turcotte, Gagnon, & Poirier, 2005. The effect of old age on the learning of supra-span sequences. Psychology and Aging, 20, 251-260.] indicate that incidental learning of visuo-spatial supra-span sequences through immediate serial recall declines with old age (Hebb's paradigm). In this study, we examined whether strategies induced by awareness of the repeated sequence might explain age differences. Young (18-35 years old) and older (65-80 years old) participants underwent either incidental or intentional learning instructions. Results indicated that older adults demonstrated reduced learning of the repeated sequence under both incidental and intentional instructions. In comparison, young adults showed superior learning of the repeated sequence in both conditions but intentional instructions triggered faster and greater learning in this age group. The results strongly indicated that knowledge of the repeated sequence enhanced learning only in the group of young adults. Older adults were unable to translate the knowledge of the repetition into elaborate strategies that would increase recall of the repeated sequence. Other findings suggest that incidental learning in young adults was mediated by both non-conscious and conscious recollection processes.     

A hierarchical model of temporal perception

Temporal perception comprises subjective phenomena such as simultaneity, successiveness, temporal order, subjective present, temporal continuity and subjective duration. These elementary temporal experiences are hierarchically related to each other. Functional system states with a duration of 30 ms are implemented by neuronal oscillations and they provide a mechanism to define successiveness. These system states are also responsible for the identification of basic events. For a sequential representation of several events time tags are allocated, resulting in an ordinal representation of such events. A mechanism of temporal integration binds successive events into perceptual units of 3 s duration. Such temporal integration, which is automatic and presemantic, is also operative in movement control and other cognitive activities. Because of the omnipresence of this integration mechanism it is used for a pragmatic definition of the subjective present. Temporal continuity is the result of a semantic connection between successive integration intervals. Subjective duration is known to depend on mental load and attentional demand, high load resulting in long time estimates. In the hierarchical model proposed, system states of 30 ms and integration intervals of 3 s, together with a memory store, provide an explanatory neuro-cognitive machinery for differential subjective duration.     

Infants use meter to categorize rhythms and melodies: implications for musical structure learning

Little is known about whether infants perceive meter, the underlying temporal structure of music. We employed a habituation paradigm to examine whether 7-month-old infants could categorize rhythmic and melodic patterns on the basis of the underlying meter, which was implied from event and accent frequency of occurrence. In Experiment 1, infants discriminated duple and triple classes of rhythm on the basis of implied meter. Experiment 2 replicated this result while controlling for rhythmic grouping structure, confirming that infants perceived metrical structure despite occasional ambiguities and conflicting group structure. In Experiment 3, infants categorized melodies on the basis of contingencies between metrical position and pitch. Infants presented with metrical melodies detected reversals of pitch/meter contingencies, while infants presented with non-metrical melodies showed no preference. Results indicate that infants can infer meter from rhythmic patterns, and that they may use this metrical structure to bootstrap their knowledge acquisition in music learning.     

Concurrent Movement Impairs Incidental But Not Intentional Statistical Learning

The effect of concurrent movement on incidental versus intentional statistical learning was examined in two experiments. In Experiment 1, participants learned the statistical regularities embedded within familiarization stimuli implicitly, whereas in Experiment 2 they were made aware of the embedded regularities and were instructed explicitly to learn these regularities. Experiment 1 demonstrated that while the control group were able to learn the statistical regularities, the resistance‐free cycling group and the exercise group did not demonstrate learning. This is in contrast with the findings of Experiment 2, where all three groups demonstrated significant levels of learning. The results suggest that the movement demands, rather than the physiological stress, interfered with statistical learning. We suggest movement activates the striatum, which is not only responsible for motor control but also plays a role in incidental learning.