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One of Mackintosh's many contributions to the comparative psychology of associative learning was in developing the distinction between the mental processes responsible for learning about features and learning about relations. His research on discrimination learning and generalisation served to highlight differences and commonalities in learning mechanisms across species and paradigms. In one such example, Wills and Mackintosh trained both pigeons and humans to discriminate between two categories of complex patterns comprising overlapping sets of abstract visual features. They demonstrated that pigeons and humans produced similar "peak-shifted" generalisation gradients when the proportion of shared features was systemically varied across a set of transfer stimuli, providing support for an elemental feature-based analysis of discrimination and generalisation. Here, we report a series of experiments inspired by this work, investigating the processes involved in post-discrimination generalisation in human category learning. We investigate how post-discrimination generalisation is affected by variability in the spatial arrangement and probability of occurrence of the visual features and develop an associative learning model that builds on Mackintosh's theoretical approach to elemental associative learning. [ABSTRACT FROM AUTHOR]

When a cue reliably predicts an outcome, the associability of that cue will change. Associative theories of learning propose this change will persist even when the same cue is paired with a different outcome. These theories, however, do not extend the same privilege to an outcome; an outcome's learning history is deemed to have no bearing on subsequent new learning involving that outcome. Two experiments were conducted which sought to investigate this assumption inherent in these theories using a serial letter-prediction task. In both experiments, participants were exposed, in Stage 1, to a predictable outcome ('X') and an unpredictable outcome ('Z'). In Stage 2, participants were exposed to the same outcomes preceded by novel cues which were equally predictive of both outcomes. Both experiments revealed that participants' learning towards the previously predictable outcome was more rapid in Stage 2 than the previously unpredicted outcome. The implications of these results for theories of associative learning are discussed. [ABSTRACT FROM AUTHOR]

The aim of this experiment was to document the role of multiple internal clock mechanisms and external sources of temporal feedback on reducing timing variability when two fingers tap instead of one (a phenomenon known as the bimanual advantage). Previous research documents a reduction in timed interval variability when two effectors time instead of one. In addition, interval variability decreases with multiple sources of feedback. To date, however, no research has explored the separate roles of feedback and internal timing on the bimanual advantage. We evaluated the bimanual advantage in a task that does not utilise an internal clock (circle drawing). Participants performed both unimanual and bimanual timing while tapping or drawing circles. Both tasks were performed with and without tactile feedback at the timing goal. We document reduced bimanual timing variability only for tasks that utilise internal clock-like timing (tapping). We also document reduced timing variability for timing with greater sensory feedback (tactile vs no-tactile feedback tapping). We conclude that internal clock mechanisms are necessary for bimanual advantage to occur, but that multiple sources of feedback can also serve to improve internal timing, which ties together current theories of bimanual advantage. [ABSTRACT FROM AUTHOR]

Most associative models typically assume that learning can be understood as a gradual change in associative strength that captures the situation into one single parameter, or representational state. We will call this view single-state learning. However, there is ample evidence showing that under many circumstances different relationships that share features can be learned independently, and animals can quickly switch between expressing one or another. We will call this multiple-state learning. Theoretically, it is understudied because it needs a different data analysis approach from those usually employed. In this article, we present a Bayesian model of the Partial Reinforcement Extinction Effect (PREE) that can test the predictions of the multiple-state view. This implies estimating the moment of change in the responses (from the acquisition to the extinction performance), both at the individual and group levels. We used this model to analyze data from a PREE experiment with three levels of reinforcement during acquisition (100%, 75% and 50%). We found differences in the estimated moment of switch between states during extinction, so that it was delayed after leaner partial reinforcement schedules. The finding is compatible with the multiple-state view. It is the first time, to our knowledge, that the predictions from the multiple-state view are tested directly. The article also aims to show the benefits that Bayesian methods can bring to the associative learning field. [ABSTRACT FROM AUTHOR]

In the OPTIMAL theory of motor learning [Wulf, G., & Lewthwaite, R. (2016). Optimizing performance through intrinsic motivation and attention for learning: The OPTIMAL theory of motor learning. Psychonomic Bulletin & Review, 23, 1382-1414], 3 factors are postulated to facilitate learning: enhanced expectancies (EE) for performance, autonomy support (AS), and an external focus (EF) of attention. In 3 recent studies, combinations of 2 of these variables resulted in superior learning relative to the presence of only 1 variable, or none. We examined whether the combination of all 3 factors would enhance learning relative to combinations of 2 factors. Our design included EE–AS, EE–EF, AS–EF, and AS–EE–EF groups. Participants threw balls at a target with their non-dominant arm. In the EE conditions, they received positive social–comparative feedback. In the AS conditions, they were allowed to throw with their dominant arm on trial blocks chosen by them. In the EF conditions, participants were asked to focus on the target. On a delayed retention test, the AS–EE–EF group outperformed all other groups. The findings provide evidence that enhanced expectancies, autonomy support, and an external focus can contribute in an additive fashion to optimize motor learning. [ABSTRACT FROM AUTHOR]

This multiple-cue judgment study investigates whether we can manipulate the judgment strategy and increase accuracy in linear and non-linear cue–criterion environments just by changing the training mode. Three experiments show that accuracy in simple linear additive task environments are improved with feedback training and intervention training, while accuracy in complex multiplicative tasks are improved with observational training. The observed interaction effect suggests that the training mode invites different strategies that are adjusted as a function of experience to the demands from the underlying cue–criterion structure. Thus, feedback and the intervention training modes invite cue abstraction, an effortful but successful strategy in combination with simple linear task structures, and observational training invites exemplar memory processes, a simple but successful strategy in combination with complex non-linear task structures. The study discusses adaptive cognition and the implication of the different training modes across a life span and for clinical populations. [ABSTRACT FROM AUTHOR]

An experiment with rats compared the ability of fixed and variable duration cues to produce blocking. Rats in group B (Blocking) were trained that both fixed- (F) and variable- (V) duration cues would be followed by food delivery. In a subsequent training stageFandVcontinued to be reinforced, butFwas accompanied byX, andVbyY. In the test phase responding toXandYwas examined. Control group O (Overshadowing) received identical treatment, except thatFandVwere nonreinforced in the first training stage. In group B there was evidence for blocking, but only ofX,which had been conditioned in compound with the fixed-durationF; there was no evidence for blocking ofY, which had been conditioned in compound with the variable-durationV. It is suggested that this result may occur because fixed cues reach a higher, more stable asymptote of associative strength than do their variable equivalents. [ABSTRACT FROM PUBLISHER]

Matching unfamiliar faces is a difficult task. Here we ask whether it is possible to improve performance by providing multiple images to support matching. In two experiments we observe that accuracy improves as viewers are provided with additional images on which to base their match. This technique leads to fast learning of an individual, but the effect is identity-specific: Despite large improvements in viewers’ ability to match a particular person's face, these improvements do not generalize to other faces. Experiment 2 demonstrated that trial-by-trial feedback provided no additional benefits over the provision of multiple images. We discuss these results in terms of familiar and unfamiliar face processing and draw out some implications for training regimes. [ABSTRACT FROM PUBLISHER]

Prior research has suggested that attention is determined by exploiting what is known about the most valid predictors of outcomes and exploring those stimuli that are associated with the greatest degree of uncertainty about subsequent events. Previous studies of human contingency learning have revealed evidence for one or other of these processes, but differences in the designs and procedures of these studies make it difficult to pinpoint the crucial determinant of whether attentional exploitation or exploration will dominate. Here we present two studies in which we systematically manipulated both the predictiveness of cues and uncertainty regarding the outcomes with which they were associated. This allowed us to demonstrate, for the first time, evidence of both attentional exploration and exploitation within the same experiment. Moreover, while the effect of predictiveness persisted to influence the rate of novel learning about the same cues in a second stage, the effect of uncertainty did not. This suggests that attentional exploration is more sensitive to a change of context than is exploitation. The pattern of data is simulated with a hybrid attentional model. [ABSTRACT FROM PUBLISHER]

It has been shown that acquired stimulus–response bindings result from at least two types of associations from the stimulus to the task (stimulus–task or stimulus–classification; S–C) and from the stimulus to the motor response (stimulus–response or stimulus–action; S–A). These types of associations have been shown to independently affect behaviour. This finding suggests that they are processed in different pathways or different parts of a pathway at the neural level. Here we test a hypothesis that such associations may be differentially affected by repetition learning and that such effects may be detected by measuring their durability against overwriting. We show that both S–C and S–A associations are in fact strengthened when learning is boosted by increasing repetitions of the primes. However, the results further suggest that associations between stimuli and actions have less durable effects on behaviour and that the durability of S–C and S–A associations is independent of repetition learning. This is an important finding for the understanding of the underlying mechanisms of associative learning and particularly raises the question of which processes may affect flexibility of learning. [ABSTRACT FROM PUBLISHER]

We propose Attribute Conditioning (AC) as a form of learning that refers to changes in people's assessment of stimuli's (CSs) attributes due to repeated pairing with stimuli possessing these attributes (USs). We review the available evidence and, based on this review, delineate three open questions and investigate them experimentally: a) the moderating role of CS-US similarity; b) the possibility of blocking; and c) the possibility of extinction. Five experiments conditioned health and athleticism. We measured AC effects on direct and indirect dependent variables (direct ratings and semantic misattribution). Experiment 1 shows that CS-US feature similarity does not moderate AC. Experiments 2 and 3 show that AC effects are insensitive to blocking; and Experiments 4 and 5 show that AC effects are resistant to extinction. These five experiments show that AC depends on CS-US contiguity, but not on CS-US contingency. Thereby, the study establishes AC as a simple learning phenomenon describing how people, stimuli, and concepts acquire specific attributes in people's minds due to mere pairings. [ABSTRACT FROM PUBLISHER]

Implicit learning is the acquisition of complex information without the intention to learn. The aim of this study was to investigate the influence of temporal regularities on the implicit learning of an artificial pitch grammar. According to the dynamic attending theory (DAT) external regularities can entrain internal oscillators that guide attention over time, inducing temporal expectations that influence perception of future events. In the present study, the presentation of the artificial pitch grammar in the exposure phase was temporally either regular or irregular for one of two participant groups. Based on the DAT, it was hypothesized that the regular temporal presentation would favour implicit learning of tone structures in comparison to the irregular temporal presentation. Results demonstrated learning of the artificial grammar for the group with the regular exposure phase and partial learning for the group with the irregular exposure phase. These findings suggest that the regular presentation helps listeners to develop perceptual expectations about the temporal occurrence of future tones and thus facilitates the learning of the artificial pitch grammar. [ABSTRACT FROM PUBLISHER]

Listeners must cope with a great deal of variability in the speech signal, and thus theories of speech perception must also account for variability, which comes from a number of sources, including variation between accents. It is well known that there is a processing cost when listening to speech in an accent other than one's own, but recent work has suggested that this cost is reduced when listening to a familiar accent widely represented in the media, and/or when short amounts of exposure to an accent are provided. Little is known, however, about how these factors (long-term familiarity and short-term familiarization with an accent) interact. The current study tested this interaction by playing listeners difficult-to-segment sentences in noise, before and after a familiarization period where the same sentences were heard in the clear, allowing us to manipulate short-term familiarization. Listeners were speakers of either Glasgow English or Standard Southern British English, and they listened to speech in either their own or the other accent, thereby allowing us to manipulate long-term familiarity. Results suggest that both long-term familiarity and short-term familiarization mitigate the perceptual processing costs of listening to an accent that is not one's own, but seem not to compensate for them entirely, even when the accent is widely heard in the media. [ABSTRACT FROM AUTHOR]

Thai offers a unique opportunity to investigate the role of lexical tone processing during visual-word recognition, as tone is explicitly expressed in its script. In order to investigate the contribution of tone at the orthographic/phonological level during the early stages of word processing in Thai, we conducted a masked priming experiment—using both lexical decision and word naming tasks. For a given target word (e.g., ห้อง/hᴐ:ŋ2/, room), five priming conditions were created: (a) identity (e.g., ห้อง/hᴐ:ŋ2/), (b) same initial consonant, but with a different tone marker (e.g., ห่อง/hᴐ:ŋ1/), (c) different initial consonant, but with the same tone marker (e.g., ศ้อง/sᴐ:ŋ2/), (d) orthographic control (different initial consonant, different tone marker; e.g., ศ่อง/sᴐ:ŋ1/), and (e) same tone homophony, but with a different initial consonant and different tone marker (e.g., ธ่อง/thᴐ:ŋ2/). Results of the critical comparisons revealed that segmental information (i.e., consonantal information) appears to be more important than tone information (i.e., tone marker) in the early stages of visual-word processing in alphabetic, tonal languages like Thai. Thus, these findings may help constrain models of visual-word recognition and reading in tonal languages. [ABSTRACT FROM PUBLISHER]

There is increasing evidence that task rules help shield the response against distractor interference. Here, the authors investigate the cognitive mechanisms underlying this assumed shielding function of task rules and how it is adjusted to changing task demands. In two experiments, participants switched between a noun categorization and an adjective categorization task. Target words were superimposed on distractor pictures. These pictures were always irrelevant and depicted either objects also used as target words in the noun task (noun distractors) or objects that were not part of the noun target-set but could be categorized according to the noun task (noun-related distractors). Results show that (a) on task repetitions shielding prevents interference from any distractors associated with a competing task; this is indicated by the lack of interference on adjective task repetitions; and (b) shielding is reduced on task switches. In the noun task, this reduction resulted in attenuated interference by noun-related distractors. In the adjective task, spatial distractors did not interfere despite the reduction. This result suggests that shielding is supported by a processing advantage for task-related information and not by distractor suppression. [ABSTRACT FROM PUBLISHER]

Determinants of a positive patterning advantage (that is, an advantage for positive patterning over negative patterning) in human causal reasoning were examined in an experiment that compared simple patterning discriminations (A, B vs. AB) to complex patterning discriminations (AB, BC, AC vs. ABC). As predicted by a cue constellation analysis of complex discriminations, a positive patterning advantage was found with complex patterning but not with simple patterning discriminations. This result may explain why some recent studies have found a positive patterning advantage where earlier studies had failed to find one. The interaction of patterning complexity with the positive patterning advantage appears to pose problems for rule-based accounts of patterning. The results support the view that associative theories of human causal reasoning are more easily distinguished from rule-based approaches when applied to conditions that make simple rules difficult to identify or implement. [ABSTRACT FROM PUBLISHER]

A number of phenomena in memory have been explained using appeals to active suppression processes, including retrieval practice, part-set cueing, and the negative priming that is observed with associative interference. However, more formal attempts to capture such processes have been absent. This paper outlines the hydrogen model of memory retrieval, which aims to be a simple model with the modest goal of trying to explore what influence suppression would have on memory retrieval. This model contains a single activation component and a single suppression component in which suppression comes into play only after retrieval interference has been detected. This model was created to explore the plausibility and viability of ideas about the operation of suppression during memory retrieval. For hydrogen, the degree of suppression recruited is proportional to the amount of interference experienced. Overall, the pattern of human data was captured by the suppression model. [ABSTRACT FROM AUTHOR]

Recent research has found that individuals can selectively forget a subset of items through directed forgetting. The goal of the present study was to replicate this selective directed forgetting effect and elucidate its underlying mechanisms. Unfortunately, results from four experiments failed to find any evidence of selective directed forgetting. Participants failed to forget any items when instructed to forget a subset of items from a first list before learning a second list. Participants were only successful in forgetting items from the first list when they were instructed to forget all items from the first list before learning the second list. [ABSTRACT FROM PUBLISHER]

Human participants received exposure to similar visual stimuli (AW and BW) that shared a common feature (W). Experiment 1 demonstrated that subsequent discrimination between AW and BW was more accurate when the two stimuli were preexposed on an intermixed schedule (AW, BW, AW, BW…) than when they were preexposed on a blocked schedule (AW, AW…BW, BW…): the intermixed–blocked effect. Furthermore, memory for the unique features of the stimuli (A and B) was better when the stimuli were preexposed on an intermixed schedule than when they were preexposed on a blocked schedule. Conversely, memory for the common features of the stimuli (W) was better when the stimuli were preexposed on a blocked schedule than when they were preexposed on an intermixed schedule. Experiment 2 again demonstrated the intermixed–blocked effect, but participants were preexposed to the stimuli in such a way that the temporal spacing between exposures to the unique features was equated between schedules. Memory for the unique and common features was similar to that found in Experiment 1. These findings support the proposal that perceptual learning depends on a mechanism that enhances memory for the unique features and reduces memory for common features. [ABSTRACT FROM PUBLISHER]

Share's self-teaching hypothesis proposes that orthographic representations are acquired via phonological decoding. A key, yet untested, prediction of this theory is that there should be an effect of word regularity on the number and quality of word-specific orthographic representations that children acquire. Thirty-four Grade 2 children were exposed to the sound and meaning of eight novel words and were then presented with those words in written form in short stories. Half the words were assigned regular pronunciations and half irregular pronunciations. Lexical decision and spelling tasks conducted 10 days later revealed that the children's orthographic representations of the regular words appeared to be stronger and more extensive than those of the irregular words. [ABSTRACT FROM PUBLISHER]

The current paper examines the applicability of the context-specific control principle to the probe selection dependence of negative-priming effects using the single-prime procedure. In a series of experiments, we highlight the applicability of the context-specific control principle, first by illustrating a key result that implicates the role of context-specific control and challenges the contextual similarity principle. Following this, we show the importance of distinct probe contexts in the single-prime negative-priming procedure and report a novel finding that illustrates a learning effect that can occur within an experimental session. Finally, we test the relation of our novel learning effect to a related learning proposal offered by Frings and Wentura (2006), and we demonstrate that the learning involved in context-specific control is not dependent on contingency learning. Overall, the patterns of results highlight the role of context-sensitive memory in controlling how current perception and action are integrated with prior experience. [ABSTRACT FROM PUBLISHER]

Reaction times for categorization of a probe face according to its sex or fame were contrasted as a function of whether the category of a preceding, sandwich-masked prime face was congruent or incongruent. Prime awareness was measured by the ability to later categorize the primes, and this was close to chance and typically uncorrelated with priming. When prime faces were never presented as visible probes within a test, priming was not reliable; when prime faces were also seen as probes, priming was only reliable if visible and masked presentation of faces were interleaved (not simply if primes had been visible in a previous session). In the latter case, priming was independent of experimentally induced face–response or face–category contingencies, ruling out any simple form of stimulus–response learning. We conclude that the reliable masked congruency priming reflects bindings between stimuli and multiple, abstract classifications that can be generated both overtly and covertly. [ABSTRACT FROM PUBLISHER]

Supervised and unsupervised categorization have been studied in separate research traditions. A handful of studies have attempted to explore a possible convergence between the two. The present research builds on these studies, by comparing the unsupervised categorization results of Pothos et al. (2011; Pothos et al., 2008) with the results from two procedures of supervised categorization. In two experiments, we tested 375 participants with nine different stimulus sets and examined the relation between ease of learning of a classification, memory for a classification, and spontaneous preference for a classification. After taking into account the role of the number of category labels (clusters) in supervised learning, we found the three variables to be closely associated with each other. Our results provide encouragement for researchers seeking unified theoretical explanations for supervised and unsupervised categorization, but raise a range of challenging theoretical questions. [ABSTRACT FROM AUTHOR]

Affix knowledge plays an important role in visual word recognition, but little is known about how it is acquired. The authors present a new method of investigating the acquisition of affixes in which participants are trained on novel affixes presented in novel word contexts (e.g., sleepnept). Experiment 1 investigated the role of semantic information on affix acquisition by comparing a form-learning condition with a condition in which participants also received definitions for each novel word. Experiment 2 investigated the role of long-term consolidation on affix acquisition by comparing knowledge of learned affixes two days and nearly two months after training. Results demonstrated that episodic knowledge of affixes can be acquired shortly after a single training session using either form or semantic learning, but suggested that the development of lexicalized representations of affixes requires the provision of semantic information during learning as well as a substantial period of offline consolidation. [ABSTRACT FROM AUTHOR]

The literature on repetition processing reveals an intriguing paradox between the particular salience of repetitions, which makes them easy to learn, and a tendency to avoid them when generating sequences. The aim of this experiment was to study the extent to which children can learn to produce these avoided behaviours by means of an artificial grammar paradigm using generation tests with implicit or explicit instructions. The analysis of the control group's performance confirmed the presence of a spontaneous tendency to avoid generating repetitions. A comparison with chance revealed that the children learned to produce repetitions in the explicit test but not in the implicit test. However, a comparison with the control group showed that learning nonetheless occurred in the experimental group with the implicit test. The discussion focused on this antirepetition behavioural bias and how it interacted with the type of information processes elicited by the tests selected for assessing implicit learning effects. [ABSTRACT FROM AUTHOR]

Two experiments explored repetition priming effects for spoken words and pseudowords in order to investigate abstractionist and episodic accounts of spoken word recognition and repetition priming. In Experiment 1, lexical decisions were made on spoken words and pseudowords with half of the items presented twice (∼12 intervening items). Half of all repetitions were spoken in a 'different voice' from the first presentations. Experiment 2 used the same procedure but with stimuli embedded in noise to slow responses. Results showed greater priming for words than for pseudowords and no effect of voice change in both normal and effortful processing conditions. Additional analyses showed that for slower participants, priming is more equivalent for words and pseudowords, suggesting episodic stimulus-response associations that suppress familiarity-based mechanisms that ordinarily enhance word priming. By relating behavioural priming to the time-course of pseudoword identification we showed that under normal listening conditions (Experiment 1) priming reflects facilitation of both perceptual and decision components, whereas in effortful listening conditions (Experiment 2) priming effects primarily reflect enhanced decision/response generation processes. Both stimulus-response associations and enhanced processing of sensory input seem to be voice independent, providing novel evidence concerning the degree of perceptual abstraction in the recognition of spoken words and pseudowords. [ABSTRACT FROM AUTHOR]

Sequence learning and spatial alternation were examined in rats with anterior thalamic lesions or sham surgeries. There was a lesion-induced deficit in spatial alternation but not in sequence learning. During sequence learning, rats discriminated between six different sequentially presented compounds (e.g., reinforce A before B, but not B before A), composed of audio-visual elements. The solution required rats to learn both specific stimulus sequences and the reward contingencies associated with these specific temporal relationships. The failure of anterior thalamic lesions to affect the acquisition of this sequential configural task complements the recent finding that anterior thalamic lesions also spare the acquisition of a configural task involving specific stimulus pairings and their spatial relationships. These findings suggest that such 'structural' learning is more reliant on cortico-hippocampal than thalamo-hippocampal interactions. [ABSTRACT FROM AUTHOR]

Categorization researchers have tried to verify their models through laboratory experiments with simplified stimulus sets, a requirement that can rarely be met in real-world situations in which properties are often connected. Still, the targeted simplification of the material might be illusory. We replicate and extend Love and Markman's (2003) study of the nonindependence of canonical stimulus properties such as size, colour, and shape in human classification learning, in which the authors concluded that shape takes precedence over other dimensions. To support their hypothesis, Love and Markman showed that certain classifications are more difficult for participants when shape is combined to one of its putative subordinate features, size or colour, than when shape is irrelevant to the task. A data set of 290 + 50 adult participants completing one or more classification tasks was collected. The results confirm that certain combinations of shape, size, and colour can hinder or facilitate classification learning, but not necessarily in the form expected by the nonindependence postulated by Love and Markman, especially in Experiment 2 where a totally reverse pattern of difficulty is observed (shape does not take precedence over other dimensions). Also, we show that simple similarity effects in clustering retain considerable intuitive appeal and can offer an alternative account to the nonindependence of stimulus properties, especially because slight variations in the dimensions chosen make the observations of Love and Markman unstable. [ABSTRACT FROM AUTHOR]

The acquisition of a negative evaluation of a fictitious minority social group in spite of the absence of any objective correlation between group membership and negative behaviours was described by Hamilton and Gifford (1976) as an instance of an illusory correlation. We studied the acquisition and attenuation through time of this correlation learning effect. In two experiments we asked for participants' judgements of two fictitious groups using an online version of a group membership belief paradigm. We tested how judgements of the two groups changed as a function of the amount of training they received. Results suggest that the perception of the illusory correlation effect is initially absent, emerges with intermediate amounts of absolute experience, but diminishes and is eliminated with increased experience. This illusory correlation effect can be considered to reflect incomplete learning rather than a bias due to information loss in judgements or distinctiveness. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The aim of this study was to conceptualize artificial grammar learning (AGL) in terms of two orthogonal dimensions—the mode of knowledge acquisition and the mode of knowledge retrieval—as was done by Perlman and Tzelgov (2006) for sequence learning. Experiment 1 was carried out to validate our experimental task; Experiments 2-4 tested, respectively, performance in the intentional, incidental, and automatic retrieval modes, for each of the three modes of acquisition. Furthermore, signal detection theory (SDT) was used as an analytic tool, consistent with our assumption that the processing of legality-relevant information involves decisions along a continuous dimension of fluency. The results presented support the analysis of AGL in terms of the proposed dimensions. They also indicate that knowledge acquired during training may include many aspects of the presented stimuli (whole strings, relations among elements, etc.). The contribution of the various components to performance depends on both the specific instruction in the acquisition phase and the requirements of the retrieval task. [ABSTRACT FROM AUTHOR]

In a previous study, we reported a dissociation between subjective expectancy and motor behaviour in a simple associative learning task (Perruchet, Cleeremans, & Destrebecqz, 2006). According to previous conditioning studies (Clark, Manns, & Squire, 2001), this dissociation is observed when the to-be-associated events coterminate and thus overlap in time (a training regimen called delay conditioning), but not when they are separated by a temporal delay (trace conditioning). In this latter situation indeed, there tends to be a direct relationship between subjective expectancy and behaviour. In this study, we further investigated this issue in a series of experiments where conscious and unconscious components of performance were pitted against each other. In Experiments 1-3, participants performed a simple reaction time task in which a preparatory signal (a tone) either overlapped with or terminated earlier than the imperative stimulus (a visual target presented in 50% of the trials). After each response, participants also had to state how much they expected the imperative stimulus to be displayed on the next trial. Results indicate that reaction times tend to decrease when the tone is consistently followed by the visual target across successive trials, whereas conscious expectancy for the target decreases at the same time. Importantly, we systematically found that the temporal relationship between the tone and the target failed to influence performance. In a fourth experiment, we examined whether these results extend to a two-choice reaction time task. To our surprise, we observed a direct relationship between subjective expectancies and reaction time in that situation. We nevertheless observed that the introduction of a delay between the tone and the target had, once again, no effect on performance. [ABSTRACT FROM AUTHOR]

Two experiments demonstrated that the prior predictive history of a cue governs the extent to which that cue engages in sequence learning. Using a serial reaction time task, we manipulated the predictiveness of the stimulus locations (cues) with respect to the location of the stimulus on the next trial (outcome), such that half of the cues were good predictors of their outcomes, whilst the other half were poorer predictors. Following this, all cues were then paired with novel outcomes. Learning about those cues that were previously established as good predictors proceeded more rapidly than learning for those cues previously established as poor predictors. When the simple recurrent network is modified to include a variable associability parameter, the effects are easily modelled. [ABSTRACT FROM AUTHOR]

According to experiential theories of language comprehension, perceptual information plays an essential role when word meanings are accessed. We conducted four experiments to investigate how different types of perceptual information such as colour and shape are combined during word access. One possibility is that the colour and shape of a word's referent are activated independently from one another and are combined in an additive manner. Alternatively, words might activate perceptual representations via a multiplicative integration of colour and shape. Experiment 1 established that participants follow a multiplicative similarity rule when they judge the similarity of schematic pictures to actual fruits and vegetables. In Experiments 2 to 4, participants performed a classification task, a lexical decision task, or a word-naming task on names of fruits and vegetables that were superimposed on a background picture. Responses were facilitated only when both colour and shape of the picture matched the word's referents. Response times were associated negatively with mean similarity ratings and the consistency of these ratings obtained in the first experiment. These results suggest a multiplicative integration of different types of perceptual information during word access. [ABSTRACT FROM AUTHOR]

Recent research highlights the importance of motor processes for a wide range of cognitive functions such as object perception and language comprehension. It is unclear, however, whether the involvement of the motor system goes beyond the processing of information that is gathered through active action experiences and affects also the representation of knowledge acquired through verbal learning. We tested this prediction by varying the presence of motor interference (i.e., squeezing a ball vs. oddball detection task) while participants verbally acquired functional object knowledge and examined the effects on a subsequent object detection task. Results revealed that learning of functional object knowledge was only impaired when participants performed an effector-specific motor task while training. The present finding of an effector-specific motor interference effect on object learning demonstrates the crucial role of the motor system in the acquisition of novel object knowledge and provides support for an embodied account to perception and cognition. [ABSTRACT FROM AUTHOR]

Theoretical analyses of perceptual learning suggest that comparison between similar stimuli aids subsequent discrimination between them. The current studies examined whether the opportunity to compare a target face to other similar faces during a preexposure phase facilitated performance on a matching task. Performance was better when the target face had been presented in alternation with similar comparator faces than if that target had not been exposed before test. Exposure to the target face without comparators, or exposure alternating with dissimilar faces, improved performance relative to the nonexposed control but performance was not as good as when target exposure was given in alternation to similar comparison faces. The effects were not influenced by image changes between exposure and test. It is suggested that exposure to a face in comparison to similar stimuli focuses the central representation of a face on its unique features. In practical terms these results suggest that reliable identification of an individual from their photograph would be improved by viewing that photograph in comparison with photographs of similar people. [ABSTRACT FROM AUTHOR]

The ability of animals to find important goals in their environment has been said to require a form of learning that is qualitatively different from that normally studied in the conditioning laboratory. Such spatial learning has been said to depend upon the construction of a global representation of the environment, and the acquisition of knowledge about the position of goals with reference to this representation is said to be unaffected by the presence of other cues or landmarks. To evaluate the first of these claims, experiments are described that investigated the extent to which the effects of training in one environment transfer to another. To evaluate the second claim, experiments are described that investigated whether cue competition effects normally found in conditioning studies can be found in spatial tasks. Overall, the results indicate that most of the phenomena of spatial learning can be explained by the principles of associative learning. The implications of the reported results for an understanding of the neural mechanisms of spatial learning are considered. [ABSTRACT FROM AUTHOR]

We present a serial reaction time (SRT) task in which participants identified the location of a target by pressing a key mapped to the location. The location of successive targets was determined by the rules of a grammar, and we varied the redundancy of the grammar. Increasing both practice and the redundancy of the grammar reduced response time, but the participants were unable to describe the grammar. Such results are usually discussed as examples of implicit learning. Instead, we treat performance in terms of retrieval from a multitrace memory. In our account, after each trial, participants store a trace comprising the current stimulus, the response associated with it, and the context provided by the immediately preceding response. When a target is presented, it is used as a prompt to retrieve the response mapped to it. As participants practise the task, the redundancy of the series helps point to the correct response and, thereby, speeds retrieval of the response. The model captured performance in the experiment and in classic SRT studies from the literature. Its success shows that the SRT task can be understood in terms of retrieval from memory without implying implicit learning. [ABSTRACT FROM AUTHOR]

Immediate serial recall of visually presented verbal stimuli is impaired by the presence of irrelevant auditory background speech, the so-called irrelevant speech effect. Two of the three main accounts of this effect place restrictions on when it will be observed, limiting its occurrence either to items processed by the phonological loop (the phonological loop hypothesis) or to items that are not too dissimilar from the irrelevant speech (the feature model). A third, the object-oriented episodic record (O-OER) model, requires only that the memory task involves seriation. The present studies test these three accounts by examining whether irrelevant auditory speech will interfere with a task that does not involve the phonological loop, does not use stimuli that are compatible with those to be remembered, but does require seriation. Two experiments found that irrelevant speech led to lower levels of performance in a visual statistical learning task, offering more support for the O-OER model and posing a challenge for the other two accounts. [ABSTRACT FROM AUTHOR]

Considerable research has examined the contrasting predictions of the elemental and configural association theories proposed by Rescorla and Wagner (1972) and Pearce (1987), respectively. One simple method to distinguish between these approaches is the summation test, in which the associative strength attributed to a novel compound of two separately trained cues is examined. Under common assumptions, the configural view predicts that the strength of the compound will approximate to the average strength of its components, whereas the elemental approach predicts that the strength of the compound will be greater than the strength of either component. Different studies have produced mixed outcomes. In studies of human causal learning, Collins and Shanks (2006) suggested that the observation of summation is encouraged by training, in which different stimuli are associated with different submaximal outcomes, and by testing, in which the alternative outcomes can be scaled. The reported experiments further pursued this reasoning. In Experiment 1, summation was more substantial when the participants were trained with outcomes identified as submaximal than when trained with simple categorical (presence/absence) outcomes. Experiments 2 and 3 demonstrated that summation can also be obtained with categorical outcomes during training, if the participants are encouraged by instruction or the character of training to rate the separately trained components with submaximal ratings. The results are interpreted in terms of apparent performance constraints in evaluations of the contrasting theoretical predictions concerning summation. [ABSTRACT FROM AUTHOR]

How effective are different types of feedback in helping us to learn multiple contingencies? This article attempts to resolve a paradox whereby, in comparison to simple outcome feedback, additional feedback either fails to enhance or is actually detrimental to performance in nonmetric multiple-cue probability learning (MCPL), while in contrast the majority of studies of metric MCPL reveal improvements at least with some forms of feedback. In three experiments we demonstrate that if feedback assists participants to infer cue polarity then it can in fact be effective in nonmetric MCPL. Participants appeared to use cue polarity information to adopt a linear judgement strategy, even though the environment was nonlinear. The results reconcile the paradoxical contrast between metric and nonmetric MCPL and support previous findings of people's tendency to assume linearity and additivity in probabilistic cue learning. [ABSTRACT FROM AUTHOR]

Sensory-motor delays vary over the course of development and under different environmental conditions. Previous research has shown that humans can compensate for the resulting temporal misalignment while performing sensory-motor tasks (e.g., Cunningham, Billock, & Tsou, 2001a), but remains silent on the question of whether perceptual learning—similar to that involved in adaptation to spatial misalignment (e.g., Redding & Wallace, 1993) and in adaptation to purely intersensory misalignment (e.g., Fujisaki, Shimojo, Kashino, & Nishida, 2004)—is also involved in this adaptive response. Following an attempted replication of Cunningham et al.'s (2001a) study in a preliminary experiment, we present in this paper two experiments that demonstrate that after-effects of adaptation to temporal misalignment do not spontaneously decay. The literature on adaptation to spatial misalignment suggests that, while instrumental learning spontaneously decays in the absence of reinforcement, perceptual learning persists. Therefore our results are consistent with adaptation being effected through perceptual learning. [ABSTRACT FROM AUTHOR]

This investigation used a newly developed artificial grammar learning (AGL) paradigm in which participants were exposed to sequences of stimuli that varied in two dimensions (colours and letters) that were superimposed on each other. Variation within each dimension was determined by a different grammar. The results of two studies strongly suggest that implicit learning in AGL depends on the goal relevance of the to-be-learned dimension. Specifically, when only one of the two stimulus dimensions was relevant for their task (Experiment 1) participants learned the structure underlying the relevant, but not that of the irrelevant dimension. However, when both dimensions were relevant, both structures were learned (Experiment 2). These findings suggest that implicit learning occurs only in dimensions to which we are attuned. Based on the present results and on those of Eitam, Hassin, and Schul (2008) we suggest that focusing on goal relevance may provide new insights into the mechanisms underlying implicit learning. [ABSTRACT FROM AUTHOR]

Human participants received unsupervised exposure to difficult-to-discriminate chequerboard stimuli (e.g., AX and BX), before learning a discrimination between them. Experiment 1 demonstrated that prior exposure enhanced later discrimination and that intermixed exposure (AX, BX, AX, BX ...) resulted in better subsequent discrimination than did blocked exposure (CY, CY ... DY, DY ...). Experiment 2 showed that simultaneous exposure to two similar stimuli (AX-BX, BX-AX ...) facilitated the later acquisition of a successive discrimination, more than successive exposure (AX-AX, BX-BX ...). These results parallel those observed by Mundy, Honey, and Dwyer (2007) who used pictures of human faces as stimuli and establish the generality of the fact that simultaneous exposure produces a particularly marked perceptual learning effect. [ABSTRACT FROM AUTHOR]

In the present study an assumption of retrieval theories of negative priming was tested. In particular, retrieval theories assume that the same underlying process causes benefits in target-to-target repetition trials and cost effects in distractor-to-target repetition trials in selection tasks in which targets are accompanied by distractor stimuli. More specifically, retrieval theories predict a negative correlation: The higher the benefit in target-to-target repetition trials is, the higher the cost effect in distractor-to-target repetition trials should be. In fact, in a study with considerable power (N = 110) and a design that allowed a confound-free detection of correlations, I observed a significant negative correlation between benefit and cost effects. This result is interpreted as evidence for a common retrieval mechanism. [ABSTRACT FROM AUTHOR]

In four experiments, the lag retention interval from parent words (e.g., blackmail, jailbird) to a conjunction word (blackbird) was manipulated in a continuous recognition task. Alterations to the basic procedure of Jones and Atchley (2002) were employed in Experiments 1 and 2 to bolster recollection to reject conjunction lures, yet conjunction error rates still decreased across lags of 1 to 20 words. Experiment 3 and a multiexperiment analysis examined the increments of forgetting in familiarity across lags of 1-20 words. Finally, in Experiment 4, participants attempted to identify conjunction probes as “old”, and the data were contrasted with those from a previous experiment (Jones & Atchley, 2002, Exp. 1), in which participants attempted not to identify conjunction probes as “old”. In support of earlier findings, the decrease in familiarity across lags of 1-20 words appears robust, with a constant level of weak recollection occurring for parent words. [ABSTRACT FROM AUTHOR]

This work examines how people interpret the sentential connective “or”, which can be viewed either inclusively (A or B or both) or exclusively (A or B but not both). Following up on prior work concerning quantifiers (Bott & Noveck, 2004; Noveck, 2001; Noveck & Posada, 2003), which shows that the common pragmatic interpretation of “some”, some but not all, is conveyed as part of an effortful step, we investigate how extra effort applied to disjunctive statements leads to a pragmatic interpretation of “or”, or but not both. Experiment 1 compelled participants to wait for three seconds before answering, hence giving them the opportunity to process the utterance more deeply. Experiments 2 and 3 emphasized “or”, either by visual means (“OR”) or by prosodic means (contrastive stress) as another way to encourage participants to apply more effort. Following a relevance-theoretic line of argument, we hypothesized that conditions encouraging more processing effort would give rise to more pragmatic inferences and hence to more exclusive interpretations of the disjunction. This prediction was confirmed in the three experiments. [ABSTRACT FROM AUTHOR]

Speech processing by human listeners derives meaning from acoustic input via intermediate steps involving abstract representations of what has been heard. Recent results from several lines of research are here brought together to shed light on the nature and role of these representations. In spoken-word recognition, representations of phonological form and of conceptual content are dissociable. This follows from the independence of patterns of priming for a word's form and its meaning. The nature of the phonological-form representations is determined not only by acoustic-phonetic input but also by other sources of information, including metalinguistic knowledge. This follows from evidence that listeners can store two forms as different without showing any evidence of being able to detect the difference in question when they listen to speech. The lexical representations are in turn separate from prelexical representations, which are also abstract in nature. This follows from evidence that perceptual learning about speaker-specific phoneme realization, induced on the basis of a few words, generalizes across the whole lexicon to inform the recognition of all words containing the same phoneme. The efficiency of human speech processing has its basis in the rapid execution of operations over abstract representations. [ABSTRACT FROM AUTHOR]

Context effects on recognition memory provide an important indirect assay of associative learning and source memory. Neuropsychological studies have indicated that such context effects may obtain even if the contexts themselves are not remembered—for example, in individuals impaired on direct tests of memory for contextual information. In contrast, a recent study indicated that the effects of temporal context reinstatement on visual recognition obtain only when the contextual information itself was explicitly recollected. Here we report that the effects of reinstatement of spatial-simultaneous context on visual object recognition memory obtain irrespective of whether those context stimuli are explicitly recognized. We suggest that spatial-simultaneous context effects might be based on ensemble unitization of target and context stimuli at encoding, whereas temporal context effects may require recollective processes. [ABSTRACT FROM AUTHOR]

When switching tasks, performance tends to be worse for n - 2 repetitions than with n - 2 switches. This n - 2 repetition cost has been hypothesized to reflect task-set inhibition: specifically, inhibition of irrelevant category-response mappings involved in response selection. This hypothesis leads to divergent predictions for situations in which all tasks involve the same stimulus categories: An n - 2 repetition cost is predicted when response sets differ across tasks, but not when the response set stays the same. The authors tested these predictions by having subjects perform relative judgements with different reference points. In Experiment 1, the stimulus categories were the same across reference points, but the response set either differed or stayed the same (the multiple- and single-mapping conditions, respectively). An n - 2 repetition cost was found in the multiple-mapping condition but not in the single-mapping condition. Experiment 2 provided evidence against the possibility that these divergent effects reflected differences in memory load. These findings confirm predictions that link n - 2 repetition costs to inhibition of irrelevant category-response mappings. [ABSTRACT FROM AUTHOR]