Explicit Awareness does not Modulate Retrograde Interference Effects in Sequence Learning

Motor sequences are learned explicitly or implicitly based on conscious awareness of the sequence. Interference happens when two sequences are learned successively. Here, we aimed to determine whether implicit and explicit sequence learning are affected differently by retrograde interference. Young healthy volunteers participated in either a control or interference group and either an explicit or implicit learning condition. We used a modified serial reaction time task to induce sequence learning and control awareness. Results showed that the overall amount of sequence learning was greater in the explicit condition compared to implicit. However, sequence learning was equally susceptible to retrograde interference under either condition. We conclude that although susceptible to interference, explicit awareness improves overall sequence learning compared to implicit conditions.     

Implicit learning revealed by the method of opposition

Complex information, such as that required for motor skills, can be learned implicitly, without awareness. Much debate has centered on the appropriate methods for proving that implicit learning is not influenced by explicit awareness. A recent study by Destrebecqz and Cleeremans has provided compelling evidence for implicit sequence learning without awareness by using the ‘method of opposition’.     

How implicit is visual statistical learning?

In visual statistical learning, participants learn the statistical regularities present in a sequence of visual shapes. A recent study (Kim, Seitz, Feenstra, & Shams, 2009) suggests that visual statistical learning occurs implicitly, as it is not accompanied by conscious awareness of these regularities. However, that interpretation of the data depends on 2 unwarranted assumptions concerning the nature and sensitivity of the tasks used to measure learning. In a replication of this study, we used a 4-choice completion task as a direct measure of learning, in addition to an indirect measure consisting of a rapid serial visual presentation task. Moreover, binary confidence judgments were recorded after each completion trial. This way, we measured systematically the extent to which sequence knowledge was available to consciousness. Supporting the notion that the role of unconscious knowledge was overestimated in Kim et al.'s study, our results reveal that participants' performance cannot be exclusively accounted for by implicit knowledge. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Implicit motor sequence learning is not purely perceptual

Many reports have indicated that implicit learning of sequences in a choice response time task is primarily perceptual; subjects learn the sequence of stimuli rather than the sequence of motor responses. Three experiments tested whether implicit motor sequence learning could be purely perceptual: no support was found for that hypothesis. Subjects who merely watched stimuli did not learn the sequence implicitly (Experiment 1), and sequence learning transferred robustly to a different set of stimulus cues (Experiment 2). In the final experiment, the stimulus-response mapping was changed at transfer so that one group of subjects pushed the same sequence of keys but saw new stimuli, whereas another group pushed a different sequence of keys but saw the same stimuli. Transfer to the new mapping was shown only if the motor sequence was kept constant, not the perceptual sequence. It is proposed that subjects learn a sequence of response locations in this and similar tasks.     

序列位置内隐学习产生机制的实验研究

内隐学习是当今认知和学习领域继内隐记忆之后又一重要的研究课题。该研究利用序列反应时研究程式,通过两个实验,对序列位置内隐学习产生的机制进行了探讨。结果表明：（１）在序列反应时任务程式中,随着反应一刺激间隔的延长,序列位置内隐学习的学习量逐渐减少;（２）异形同模式迁移组和异形异模式迁移组被试间内隐学习量无显著差异,被试未能内隐地习得抽象的序列模式。说明序列位置内隐学习产生的基础是水平联结,在该实验条件下没有发现垂直联结存在的证据。     

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。     

An old problem: how can we distinguish between conscious and unconscious knowledge acquired in an implicit learning task?

A long lasting debate in the field of implicit learning is whether participants can learn without acquiring conscious knowledge. One crucial problem is that no clear criterion exists allowing to identify participants who possess explicit knowledge. Here, we propose a method to diagnose during a serial reaction time task those participants who acquire conscious knowledge. We first validated this method by using Stroop-like material during training. Then we assessed participants’ knowledge with the Inclusion/Exclusion task (Experiment 1) and the wagering task (Experiment 2). Both experiments confirmed that for participants diagnosed as having acquired conscious knowledge about the underlying sequence the Stroop congruency effect disappeared, whereas for participants not diagnosed as possessing conscious knowledge it only slightly decreased. In addition, both experiments revealed that only participants diagnosed as conscious were able to strategically use their acquired knowledge. Thus, our method allows to reliably distinguish between participants with and without conscious knowledge.     

Effects of sequence length and structure on implicit serial learning

Some data suggest that, as in explicit serial learning, longer sequences are more difficult to learn implicitly. These findings have been used to support the inference that implicit learning is capacity-limited. However, investigations of the effect of sequence length on implicit learning have confounded sequence structure with sequence length. These factors were manipulated independently in 3 experiments using a serial reaction time task. The results showed that sequence structure, not sequence length, largely determines the extent of sequence learning.     

Characteristics of implicit chaining in cotton-top tamarins (Saguinus oedipus)

In human cognition there has been considerable interest in observing the conditions under which subjects learn material without explicit instructions to learn. In the present experiments, we adapted this issue to nonhumans by asking what subjects learn in the absence of explicit reinforcement for correct responses. Two experiments examined the acquisition of sequence information by cotton-top tamarins (Saguinus oedipus) when such learning was not demanded by the experimental contingencies. An implicit chaining procedure was used in which visual stimuli were presented serially on a touchscreen. Subjects were required to touch one stimulus to advance to the next stimulus. Stimulus presentations followed a pattern, but learning the pattern was not necessary for reinforcement. In Experiment 1 the chain consisted of five different visual stimuli that were presented in the same order on each trial. Each stimulus could occur at any one of six touchscreen positions. In Experiment 2 the same visual element was presented serially in the same five locations on each trial, thereby allowing a behavioral pattern to be correlated with the visual pattern. In this experiment two new tests, a Wild-Card test and a Running-Start test, were used to assess what was learned in this procedure. Results from both experiments indicated that tamarins acquired more information from an implicit chain than was required by the contingencies of reinforcement. These results contribute to the developing literature on nonhuman analogs of implicit learning.     

片段再认任务在内隐序列学习研究中的有效性检验

内隐序列学习到底能习得何种知识呢？已有研究从任务分离范式发展到加工分离程序试图来捕获习得的知识。本研究根据信号检测论原理把三元素再认测验的成绩离析成击中率和虚报率, 再试图运用加工分离程序的思想来分离习得的意识知识和无意识知识, 为示区别将这种测验命名为片段再认任务, 并以序列生成任务为效标, 通过两个实验来检验片段再认任务的效度和敏感性。实验1以反应–刺激间隔(RSI)为自变量来检验片段再认任务和序列生成任务在测量习得知识上的效度, 结果显示前者的效度高于后者; 实验2进行测验的敏感性分析, 以参与度为自变量, 结果表明前者更为灵敏所以测量效度高。总之, 与序列生成任务相比, 片段再认任务是一种高效而灵敏的测量工具。     

Social intuition as a form of implicit learning: Sequences of body movements are learned less explicitly than letter sequences

In the current paper, we first evaluate the suitability of traditional serial reaction time (SRT) and artificial grammar learning (AGL) experiments for measuring implicit learning of social signals. We then report the results of a novel sequence learning task which combines aspects of the SRT and AGL paradigms to meet our suggested criteria for how implicit learning experiments can be adapted to increase their relevance to situations of social intuition. The sequences followed standard finite-state grammars. Sequence learning and consciousness of acquired knowledge were compared between 2 groups of 24 participants viewing either sequences of individually presented letters or sequences of body-posture pictures, which were described as series of yoga movements. Participants in both conditions showed above-chance classification accuracy, indicating that sequence learning had occurred in both stimulus conditions. This shows that sequence learning can still be found when learning procedures reflect the characteristics of social intuition. Rule awareness was measured using trial-by-trial evaluation of decision strategy (Dienes & Scott, 2005; Scott & Dienes, 2008). For letters, sequence classification was best on trials where participants reported responding on the basis of explicit rules or memory, indicating some explicit learning in this condition. For body-posture, classification was not above chance on these types of trial, but instead showed a trend to be best on those trials where participants reported that their responses were based on intuition, familiarity, or random choice, suggesting that learning was more implicit. Results therefore indicate that the use of traditional stimuli in research on sequence learning might underestimate the extent to which learning is implicit in domains such as social learning, contributing to ongoing debate about levels of conscious awareness in implicit learning.     

学优生与学困生内隐与外显协同学习的比较研究

根据目前国内采用的标准,选取学优生和学困生各120人。运用内隐学习中的双条件人工语法材料和强分离的实验范式,考察和比较了两种学生的内隐学习、内隐与外显协同学习的成绩。结果显示:(1)学优生在外显学习、协同学习(先内隐后外显以及内隐与外显交替)方式下的成绩显著好于学困生,而在内隐学习方式下,二者成绩差异不显著。(2)学优生的外显学习及协同学习成绩显著好于内隐学习成绩,而学困生在四种学习方式下成绩差异不显著。表明在人工语法学习中学优生的有意识学习及其与无意识的协同学习效果较好,而学困生的有意识学习及协同学习较差。     

Fringe consciousness in sequence learning: the influence of individual differences

We first describe how the concept of “fringe consciousness” ([Mangan, 1993a], [Mangan, 1993b], [Mangan, 2001] and [Mangan, 2003]) can characterise gradations of consciousness between the extremes of implicit and explicit learning. We then show that the NEO-PI-R personality measure of openness to feelings, chosen to reflect the ability to introspect on fringe feelings, influences both learning and awareness in the serial reaction time (SRT) task under conditions that have previously been associated with implicit learning ([Destrebecqz and Cleeremans, 2001] and [Destrebecqz and Cleeremans, 2003]). This provides empirical evidence for the proposed phenomenology and functional role of fringe consciousness in so-called implicit learning paradigms (Mangan, 1993b). Introducing an individual difference variable also helped to identify possible limitations of the exclusion task as a measure of conscious sequence knowledge. Further exploration of individual differences in fringe awareness may help to avoid polarity in the implicit learning debate, and to resolve apparent inconsistencies between previous SRT studies.     

Implicit sequence learning and conscious awareness

This paper uses the Process Dissociation Procedure to explore whether people can acquire unconscious knowledge in the serial reaction time task [Destrebecqz, A., & Cleeremans, A. (2001). Can sequence learning be implicit? New evidence with the Process Dissociation Procedure. Psychonomic Bulletin &Review, 8, 343-350; Wilkinson, L., & Shanks, D. R. (2004). Intentional control and implicit sequence learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 30, 354-369]. Experiment 1 showed that people generated legal sequences above baseline levels under exclusion instructions. Reward moved exclusion performance towards baseline, indicating that the extent of motivation in the test phase influenced the expression of unconscious knowledge. Experiments 2 and 3 revealed that even with reward, adding noise to the sequences or shortening training led to above-baseline exclusion performance, suggesting that task difficulty and the amount of training also affected the expression of unconscious knowledge. The results help resolve some current debates about the role of conscious awareness in sequence learning.     

Implicit learning of semantic preferences of English words by Chinese learners

The aim of the present study was to explore whether Chinese learners could implicitly learn the semantic preferences of novel English words. In training, participants learned four novel verbs and were exposed to a set of verb-noun phrases that included these new words. What the participants were not told was that the use of the verbs depended on the concreteness of the nouns (i.e., the semantic preference rule). In testing, participants were required to choose between two possible verbs (one of which violated the semantic preference rule) for nouns that never occurred in training. The results showed that participants acquired unconscious knowledge of semantic preferences under incidental learning conditions, as measured by verbal reports and structural knowledge attributions. Our results provide further evidence for implicit learning of semantic preferences, suggesting that implicit learning is an important mechanism in the acquisition of L2 collocations.     

Implicit learning of fifth- and sixth-order sequential probabilities

Serial reaction time (SRT) task studies have established that people can implicitly learn sequential contingencies as complex as fourth-order probabilities. The present study examined people’s ability to learn fifth-order (Experiment 1) and sixth-order (Experiment 2) probabilities. Remarkably, people learned fifth- and sixth-order probabilities. This suggests that the implicit sequence learning mechanism can operate over a range of at least seven sequence elements.     

Implicit learning of evaluative vs. non-evaluative covariations: The role of dimension accessibility

Implicit covariation learning, the development of simple associations without awareness, has been demonstrated repeatedly along the evaluative dimension [De Houwer, J., Thomas, S., & Baeyens, F. (2001). Associative learning of likes and dislikes: A review of 25 years of research on human evaluative conditioning. Psychological Bulletin, 127, 853-869], but associations involving other dimensions appear more difficult to learn implicitly. The present research highlights the unique properties of the evaluative dimension that may predispose it to implicit learning. We provide evidence in the first experiment that implicit covariation learning occurs along the evaluative dimension, but does not spontaneously occur along non-evaluative dimensions. In Experiment 2, implicit learning along non-evaluative dimensions occurred when participants were subliminally primed with the to-be-learned dimension. In the discussion, we integrate findings from implicit evaluative conditioning research with the broader implicit learning literature.     

The Relation Between Implicit and Explicit Learning: Evidence for Parallel Development

Much research has focused on the separability of implicit and explicit learning, but less has focused on how they might interact. A recent model suggests that in the motor-skill domain, explicit knowledge can guide movement, and the implicit system learns in parallel, based on these movements. Functional imaging studies do not support that contention, however; they indicate that learning is exclusively implicit or explicit. In the experiment reported here, participants learned a motor sequencing task either implicitly or explicitly. At transfer, most of the stimuli were random, but the sequence occasionally appeared; thus, it was not obvious that explicit knowledge could be applied to the task. Nevertheless, participants with explicit training showed sequence knowledge equivalent to those with implicit training, implying that implicit knowledge had been acquired in parallel with explicit knowledge. This result has implications for the development of automaticity and of motor-skill learning.     

汉语声调远距离规则的内隐学习及其迁移效应

内隐学习研究领域的一个重要问题是内隐学习获得的知识究竟是什么,即内隐学习获得的知识究竟是底层的抽象规则还是表面的特征.研究以汉语声调的远距离水平映射这一远距离规则为材料,通过对表面特征和底层规则之间的分离操作,在控制组块和重复结构等表面特征的条件下,探讨声调远距离规则的习得和迁移,结果发现被试能够内隐地习得和迁移汉语平仄声调的水平映射规则,证实了内隐学习确实能够获得底层的抽象规则,为内隐学习的抽象性问题提供了新的证据.     

Visual artificial grammar learning by rhesus macaques (<Emphasis Type="Italic">Macaca mulatta</Emphasis>): exploring the role of grammar complexity and sequence length

Humans and nonhuman primates can learn about the organization of stimuli in the environment using implicit sequential pattern learning capabilities. However, most previous artificial grammar learning studies with nonhuman primates have involved relatively simple grammars and short input sequences. The goal in the current experiments was to assess the learning capabilities of monkeys on an artificial grammar-learning task that was more complex than most others previously used with nonhumans. Three experiments were conducted using a joystick-based, symmetrical-response serial reaction time task in which two monkeys were exposed to grammar-generated sequences at sequence lengths of four in Experiment 1, six in Experiment 2, and eight in Experiment 3. Over time, the monkeys came to respond faster to the sequences generated from the artificial grammar compared to random versions. In a subsequent generalization phase, subjects generalized their knowledge to novel sequences, responding significantly faster to novel instances of sequences produced using the familiar grammar compared to those constructed using an unfamiliar grammar. These results reveal that rhesus monkeys can learn and generalize the statistical structure inherent in an artificial grammar that is as complex as some used with humans, for sequences up to eight items long. These findings are discussed in relation to whether or not rhesus macaques and other primate species possess implicit sequence learning abilities that are similar to those that humans draw upon to learn natural language grammar.