The tight coupling between category and causal learning

The main goal of the present research was to demonstrate the interaction between category and causal induction in causal model learning. We used a two-phase learning procedure in which learners were presented with learning input referring to two interconnected causal relations forming a causal chain (Experiment 1) or a common-cause model (Experiments 2a, b). One of the three events (i.e., the intermediate event of the chain, or the common cause) was presented as a set of uncategorized exemplars. Although participants were not provided with any feedback about category labels, they tended to induce categories in the first phase that maximized the predictability of their causes or effects. In the second causal learning phase, participants had the choice between transferring the newly learned categories from the first phase at the cost of suboptimal predictions, or they could induce a new set of optimally predictive categories for the second causal relation, but at the cost of proliferating different category schemes for the same set of events. It turned out that in all three experiments learners tended to transfer the categories entailed by the first causal relation to the second causal relation.     

Action-effect binding by observational learning

The acquisition of bidirectional action–effect associations plays a central role in the ability to intentionally control actions. Humans learn about actions not only through active experience, but also through observing the actions of others. In Experiment 1, we examined whether action–effect associations can be acquired by observational learning. To this end, participants observed how a model repeatedly pressed two buttons during an observation phase. Each of the buttonpresses led to a specific tone (action effect). In a subsequent test phase, the tones served as target stimuli to which the participants had to respond with buttonpresses. Reaction times were shorter if the stimulus–response mapping in the test phase was compatible with the action–effect association in the observation phase. Experiment 2 excluded the possibility that the impact of perceived action effects on own actions was driven merely by an association of spatial features with the particular tones. Furthermore, we demonstrated that the presence of an agent is necessary to acquire novel action–effect associations through observation. Altogether, the study provides evidence for the claim that bidirectional action–effect associations can be acquired by observational learning. Our findings are discussed in the context of the idea that the acquisition of action–effect associations through observation is an important cognitive mechanism subserving the human ability for social learning.     

Category label and response location shifts in category learning

The category shift literature suggests that rule-based classification, an important form of explicit learning, is mediated by two separate learned associations: a stimulus-to-label association that associates stimuli and category labels, and a label-to-response association that associates category labels and responses. Three experiments investigate whether information–integration classification, an important form of implicit learning, is also mediated by two separate learned associations. Participants were trained on a rule-based or an information–integration categorization task and then the association between stimulus and category label, or between category label and response location was altered. For rule-based categories, and in line with previous research, breaking the association between stimulus and category label caused more interference than breaking the association between category label and response location. However, no differences in recovery rate emerged. For information–integration categories, breaking the association between stimulus and category label caused more interference and led to greater recovery than breaking the association between category label and response location. These results provide evidence that information–integration category learning is mediated by separate stimulus-to-label and label-to-response associations. Implications for the neurobiological basis of these two learned associations are discussed.     

Contextual interference in implicit and explicit motor learning

The purposes of this study were to examine the contextual interference effect in implicit learning and to compare implicit and explicit learning. Thirty-two participants performed a pursuit-tracking task for 60 acquisition and ten retention trials. The middle segment of target pathways had only two patterns whereas other segments had random patterns. A combination of awareness and practice order for the middle segment created four acquisition conditions: implicit-blocked, implicit-serial, explicit-blocked and explicit-serial. A questionnaire and a recognition test revealed that implicit groups were unaware of the repetition. Results showed no contextual interference effect in either implicit or explicit learning. Acquisition and retention performances were better for the middle segment than the other segments regardless of awareness. No difference between the implicit and explicit groups was found, suggesting that the implicit learning condition led to learning equivalent to the explicit learning condition.     

Auditory expectations for newly acquired structures

Our study investigated whether newly acquired auditory structure knowledge allows listeners to develop perceptual expectations for future events. For that aim, we introduced a new experimental approach that combines implicit learning and priming paradigms. Participants were first exposed to structured tone sequences without being told about the underlying artificial grammar. They then made speeded judgements on a perceptual feature of target tones in new sequences (i.e., in-tune/out-of-tune judgements). The target tones respected or violated the structure of the artificial grammar and were thus supposed to be expected or unexpected. In this priming task, grammatical tones were processed faster and more accurately than ungrammatical ones. This processing advantage was observed for an experimental group performing a memory task during the exposure phase, but was not observed for a control group, which was lacking the exposure phase (Experiment 1). It persisted when participants realized an in-tune/out-of-tune detection task during exposure (Experiment 2). This finding suggests that the acquisition of new structure knowledge not only influences grammaticality judgements on entire sequences (as previously shown in implicit learning research), but allows developing perceptual expectations that influence single event processing. It further promotes the priming paradigm as an implicit access to acquired artificial structure knowledge.     

心理疾病污名内隐测评的类别标签初探

采用单一类型内隐联想测验,考察以往研究中常用的概括化心理疾病词和具体心理疾病词作为心理疾病内隐污名间接测量概念词或类别标签的有效性。结果发现,相较于与积极词配对的任务,两类概念词与消极词（心理疾病态度词）配对的任务反应时更快,正确率更高。研究表明概括化概念和具体疾病与反映人们对心理疾病患者真实态度的消极词存在更紧密的自动联结,是人们头脑中表征心理疾病的概念词或类别标签,可作为内隐测量中的心理疾病概念词用于污名评估。     

Implicit learning of what comes when and where within a sequence: The time-course of acquiring serial position-item and item-item associations to represent serial order

Much research has been conducted aimed at the representations and mechanisms that enable learning of sequential structures. A central debate concerns the question whether item-item associations (i.e., in the sequence A-B-C-D, B comes after A) or associations of item and serial list position (i.e., B is the second item in the list) are used to represent serial order. Previously, we showed that in a variant of the implicit serial reaction time task, the sequence representation contains associations between serial position and item information (Schuck, Gaschler, Keisler, & Frensch, 2011). Here, we applied models and research methods from working memory research to implicit serial learning to replicate and extend our findings. The experiment involved three sessions of sequence learning. Results support the view that participants acquire knowledge about order structure (item-item associations) and about ordinal structure (serial position-item associations). Analyses suggest that only the simultaneous use of the two types of knowledge acquisition can explain learning-related performance increases. Additionally, our results indicate that serial list position information plays a role very early in learning and that inter-item associations increasingly control behavior in later stages.     

Associations between visual attention,implicit and explicit attitude and behaviour for physical activity

The current study explored associations between previous physical activity and both implicit and explicit attitudes, as well as visual attention and activity motivation (intention). Analyses were performed on participants initially unaware of the physical activity focus of the study (N = 98). Higher levels of physical activity were associated with positive implicit attitudes and an attentional bias towards exercise cues. There was a quadratic (‘U’ shaped) relationship between implicit attitude and attention: the more extreme individuals’ implicit attitudes towards exercise (positive or negative) the greater their attentional bias to exercise cues. Furthermore, explicit attitude moderated the relationship between attentional bias and physical activity: attentional bias to exercise cues was associated with higher levels of physical activity only for those who had a strong positive explicit attitude. Findings suggested that implicit cognitions are linked with previous physical activity. Future research should consider strategies for strengthening positive implicit and explicit attitudes and directing attention to cues signalling healthy behaviour.     

Implicit learning of new verbal associations

Implicit learning of a series of new verbal associations was studied in four experiments. The first two experiments demonstrated that learning of a repeating sequence of verbal stimuli may occur without awareness, but only when the stimulus-response mapping requires an attention-demanding activity: Subjects who were unaware of the sequence learned when instructed to categorize the stimuli, but not when instructed simply to read them. However, in both situations, unaware subjects performed no better than untrained control subjects in expressing their knowledge of the sequence explicitly. In Experiments 3 and 4, subjects showed implicit learning when the task involved either motor responses to verbal stimuli or verbal responses to spatially arranged stimuli. These findings are discussed in terms of the conditions under which implicit learning can be obtained. First, they demonstrate implicit learning of a set of new associations in the verbal domain. Second, the data suggest that attention is important in implicit learning. Finally, the degree of interitem organization that is familiar preexperimentally seems to partially determine the amount of implicit learning.     

Evidence for an implicit influence of memory on future thinking

The capacity to think about specific events that one might encounter in the future—episodic future thought— involves the flexible (re)organization of memory. The present study demonstrates that implicit processes play an important role here. In two experiments (N = 180), participants were asked to generate a personal event that they expected to plausibly occur in the following week. The content of the participants’ responses was biased (i.e., primed) by recent thoughts about a specific category of experiences. For instance, participants who had recently been induced to think about social experiences, in the context of an ostensibly unrelated task, were more likely than nonprimed participants to generate similar events occurring in their immediate future. Importantly, the participants were unaware of this unintentional influence of memory. The theoretical and practical implications of these findings for understanding episodic future thought and its relation to memory are discussed.     

Effect anticipation and action control

According to the authors' 2-phase model of action control, people first incidentally acquire bidirectional associations between motor patterns and movement-contingent events and then intentionally use these associations for goal-directed action. The authors tested the model in 4 experiments, each comprising an acquisition phase, in which participants experienced co-occurrences between left and right keypresses and low- and high-pitched tones, and a test phase, in which the tones preceded the responses in forced- and free-choice designs. Both reaction time and response frequency in the test phase depended on the learned associations, indicating that presenting a tone activated the associated response. Results are interpreted as evidence for automatic action-outcome integration and automatic response priming through learned action effects. These processes may be basic for the control of voluntary action by the anticipation of action goals.     

Implicit transfer of spatial structure in visuomotor sequence learning

Implicit learning and transfer in sequence learning are essential in daily life. Here, we investigated the implicit transfer of visuomotor sequences following a spatial transformation. In the two experiments, participants used trial and error to learn a sequence consisting of several button presses, known as the m × n task (Hikosaka et al., 1995). After this learning session, participants learned another sequence in which the button configuration was spatially transformed in one of the following ways: mirrored, rotated, and random arrangement. Our results showed that even when participants were unaware of the transformation rules, accuracy of transfer session in the mirrored and rotated groups was higher than that in the random group (i.e., implicit transfer occurred). Both those who noticed the transformation rules and those who did not (i.e., explicit and implicit transfer instances, respectively) showed faster performance in the mirrored sequences than in the rotated sequences. Taken together, the present results suggest that people can use their implicit visuomotor knowledge to spatially transform sequences and that implicit transfers are modulated by a transformation cost, similar to that in explicit transfer.     

Acquired affective associations induce emotion effects in word recognition: An ERP study

The present study examined how contextual learning and in particular emotionality conditioning impacts the neural processing of words, as possible key factors for the acquisition of words’ emotional connotation. 21 participants learned on five consecutive days associations between meaningless pseudowords and unpleasant or neutral pictures using an evaluative conditioning paradigm. Subsequently, event-related potentials were recorded while participants implicitly processed the learned emotional relevance in a lexical decision paradigm. Emotional and neutral words were presented together with the conditioned pseudowords and a set of new pseudowords. Conditioned and new pseudowords differed in the late positive complex. Emotionally and neutrally conditioned stimuli differed in an early time window (80–120 ms) and in the P300. These results replicate ERP effects known from emotion word recognition and indicate that contextual learning and in particular evaluative conditioning is suitable to establish emotional associations in words, and to explain early ERP effects in emotion word recognition.     

Is implicit learning perceptually inflexible? New evidence using a simple cued reaction-time task

Considerable research has been devoted to investigating learning without awareness. Burke and Roodenrys [Burke, D., & Roodenrys, S. (2000). Implicit learning in a simple cued reaction-time task. Learning and Motivation 31, 364–380] developed a simple learning task in which a cue shape predicts the arrival of a target shape (to which subjects respond) in a sequence of rapidly presented shapes, and found that all subjects responded faster to cued targets than to uncued targets, even those classified as unaware of the cue–target relationship. Two experiments were conducted to examine the perceptual flexibility of implicit (and explicit) learning using the paradigm developed by Burke and Roodenrys (2000). Perceptual flexibility was examined by altering the perceptual features of the cue shape. The results of the first experiment indicated the implicit, but not explicit, learning that occurs in this paradigm is perceptually inflexible. However, the second experiment indicated that perceptually flexible implicit learning can be encouraged by varying the nature of the experimental stimuli. These experiments therefore provide support for processing accounts of transfer.     

未意识到错误影响错误后调整的电生理证据

现有研究一致认为意识到错误可引起错误后调整, 但是未意识到错误能否促使个体进行错误后调整尚存争议。本实验采用基于go/no-go范式的错误意识任务考察上述问题, 并根据被试对自己按键反应正误主观报告将no-go错误反应分为意识到错误和未意识到错误。行为结果发现, 意识到错误和未意识到错误后正确率均显著高于正确击中试次(正确go试次)后正确率; 但是, 意识到错误后试次反应时显著快于正确击中后反应时, 未意识到错误后反应时显著慢于正确击中后反应时。该结果表明两类错误均优化了错误后行为表现, 但是意识到错误后被试调整速度加快, 未意识到错误后被试调整速度减慢。进而, 时频分析发现意识到错误相较于未意识到错误诱发显著更强的alpha波能量。并且, 前者在错误意识主观报告前已诱发alpha波, 后者在错误意识主观报告反应后诱发alpha波。该结果表明意识到错误一直处于持续的注意监控中, 而未意识到错误是任务引起的暂时注意控制。因此, 本实验说明错误意识影响错误后调整, 意识到错误可能采用类似主动性控制的策略调节错误后行为, 而未意识到错误可能采用类似反应性控制的策略调节错误后行为。     

Event Timing and age deficits in higher-order sequence learning

Recent studies have reported age deficits in learning sequences that contain subtle sequential regularities (e.g., Curran (1997) Psychological Research, 60(1-2), 24; D. V. Howard et al. (2004) Psychology and Aging, 19(1), 79; Howard, J. H. Jr, & Howard, D. V. (1997). Psychology and Aging, 12(4), 634). This finding is of potential theoretical interest, but the contribution of sequence event timing to this deficit has not been investigated. This study used an alternating serial reaction time task to examine implicit sequence learning in young adults when event timing mimicked that experienced by older adults in previous research. We varied the response-to-stimulus interval directly in Experiment 1 and indirectly by degrading the stimuli to influence response time in Experiment 2. Results indicate that these "aged" young adults learned the higher-order sequence structure implicitly, but they learned less than young controls and more than old adults on some measures of implicit learning in both experiments. In addition, these two different experimental manipulations produced distinct patterns of deficits despite having nearly identical effects on event sequence timing. These findings suggest that event timing alone cannot explain the age deficits observed in high-order implicit sequence learning.     

Bidirectional lexical-gustatory synesthesia

In developmental lexical–gustatory synesthesia, specific words (inducers) can trigger taste perceptions (concurrents) and these synesthetic associations are generally stable. We describe a case of multilingual lexical–gustatory synesthesia for whom some synesthesias were bidirectional as some tastes also triggered auditory word associations. Evoked concurrents could be gustatory but also tactile sensations. In addition to words and pseudowords, many voices were effective inducers, suggesting increased connections between cortical taste areas and both voice-selective and language-selective areas. Lasting changes in some evoked tastes occurred during childhood suggesting that some plasticity can be present after the initial learning of associations. Inducers were often linked to taste concurrents phonologically or semantically, but also through identifiable childhood episodes (persons or events). Several inducers were phonologically linked to episodic inducers suggesting a process of secondary acquisition for many inducers. Implications of these observations are discussed.     

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.     

Learning words’ sounds before learning how words sound: 9-Month-olds use distinct objects as cues to categorize speech information

One of the central themes in the study of language acquisition is the gap between the linguistic knowledge that learners demonstrate, and the apparent inadequacy of linguistic input to support induction of this knowledge. One of the first linguistic abilities in the course of development to exemplify this problem is in speech perception: specifically, learning the sound system of one’s native language. Native-language sound systems are defined by meaningful contrasts among words in a language, yet infants learn these sound patterns before any significant numbers of words are acquired. Previous approaches to this learning problem have suggested that infants can learn phonetic categories from statistical analysis of auditory input, without regard to word referents. Experimental evidence presented here suggests instead that young infants can use visual cues present in word-labeling situations to categorize phonetic information. In Experiment 1, 9-month-old English-learning infants failed to discriminate two non-native phonetic categories, establishing baseline performance in a perceptual discrimination task. In Experiment 2, these infants succeeded at discrimination after watching contrasting visual cues (i.e., videos of two novel objects) paired consistently with the two non-native phonetic categories. In Experiment 3, these infants failed at discrimination after watching the same visual cues, but paired inconsistently with the two phonetic categories. At an age before which memory of word labels is demonstrated in the laboratory, 9-month-old infants use contrastive pairings between objects and sounds to influence their phonetic sensitivity. Phonetic learning may have a more functional basis than previous statistical learning mechanisms assume: infants may use cross-modal associations inherent in social contexts to learn native-language phonetic categories.     

How does prior knowledge affect implicit and explicit concept learning?

Two experiments investigated the effect of prior knowledge on implicit and explicit learning. Implicit as opposed to explicit learning is sometimes characterized as unselective or purely statistical. During training, one group of participants was presented with category exemplars whose features could be tied together by integrative knowledge, whereas another group saw category exemplars with unrelated feature combinations. Half of the participants in each group learned these categories under a secondary-task condition (meant to discourage explicit learning), and the remaining half performed the categorization task under a single-task condition (meant to favour explicit learning). In a test phase, participants classified only the individual features of the training exemplars. Secondary- as opposed to single-task conditions impaired explicit but not implicit knowledge (as determined by subjective measures). Importantly, prior knowledge resulted in increased amounts of both implicit and explicit knowledge.