Motor learning by observation: Evidence from a serial reaction time task

This study sought evidence of observational motor learning, a type of learning in which observation of the skilled performance of another person not only facilitates motor skill acquisition but does so by contributing to the formation of effector-specific motor representations. Previous research has indicated that observation of skilled performance engages cognitive processes similar to those occurring during action execution or physical practice, but has not demonstrated that these include processes involved in effector-specific representation. In two experiments, observer subjects watched the experimenter performing a serial reaction time (SRT) task with a six-item unique sequence before sequence knowledge was assessed by response time and/or free generation measures. The results suggest that: (1) subjects can acquire sequence information by watching another person performing the task (Experiments 1-2); (2) observation results in as much sequence learning as task practice when learning is measured by reaction times (RTs) and more than task practice when sequence learning is measured by free generation performance (Experiment 2, Part 1); and (3) sequence knowledge acquired by model observation can be encoded motorically--that is, in an effector-specific fashion (Experiment 2, Part 2).     

Nonintentional task set activation: Evidence from implicit task sequence learning

Studies have shown that task sets could be configured endogenously (i.e., on the basis of memory) according to an explicit sequence or exogenously according to a task cue. In two experiments, we examined whether an implicitly learned sequence could facilitate task set configuration without participants’ intention. These experiments led to opposite conclusions regarding this question, but their methodology made it impossible to distinguish between the interpretations. We altered the task-switching paradigm by embedding a hidden task sequence, while randomizing all other aspects, including perceptual (i.e., task cues) and motor elements. We found that a sequence of tasks, proper, was learned implicitly and that the memory of that sequence endogenously facilitated task decision processes without the participants’ explicit knowledge.     

Mindfulness reduces habitual responding based on implicit knowledge: Evidence from artificial grammar learning

Participants were unknowingly exposed to complex regularities in a working memory task. The existence of implicit knowledge was subsequently inferred from a preference for stimuli with similar grammatical regularities. Several affective traits have been shown to influence AGL performance positively, many of which are related to a tendency for automatic responding. We therefore tested whether the mindfulness trait predicted a reduction of grammatically congruent preferences, and used emotional primes to explore the influence of affect. Mindfulness was shown to correlate negatively with grammatically congruent responses. Negative primes were shown to result in faster and more negative evaluations. We conclude that grammatically congruent preference ratings rely on habitual responses, and that our findings provide empirical evidence for the non-reactive disposition of the mindfulness trait.     

Frames of reference in perceptual-motor learning: Evidence from a blind manual positioning task

Participants moved a joystick to bring a computer-displayed cursor to each of six on-screen target locations arrayed around the center of the screen. At the start of each trial, the stick rested vertically, with a cursor occupying the center of the screen. A target appeared at another location and as soon as the stick was moved away from its rest position the cursor disappeared until the participant pressed a trigger on the stick to indicate when s/he thought the stick-controlled cursor was at the target site. With training, participants improved on the blind positioning task, but when conditions changed their performance suffered. Changing the hand used in the task or the location of the stick caused approximately equal disruptions, but changing both hand and location was significantly more disruptive than changing just one feature. The results support the hypothesis that perceptual-motor learning entails coding of extrinsic (spatial coordinates) as well as intrinsic (postural or body movement) information. Received: 14 October 1999 / Accepted: 6 November 2000     

Time perception is enhanced by task duration knowledge: Evidence from experienced swimmers

The present study deals with the impact on temporal estimation of previous knowledge about the duration of a specific task (referred to as ??task duration knowledge??). Athletes were recruited in this study because they are assumed to have high levels of task duration knowledge in their discipline. In Experiment 1, 28 elite swimmers had to estimate the time it would take to swim a given distance using two different strokes for which they had different task duration knowledge levels. The swimmers estimated duration more accurately and with less uncertainty in the high-knowledge than in the low-knowledge condition. In Experiment 2, the swimmers had to produce 36?s of swimming in various contexts that altered the retrieval of their task duration knowledge, with and without a secondary task. When swimmers could not rely on their task duration knowledge, their productions were more affected by the secondary task. In Experiment 3, the swimmers were more precise at producing time when visualising something that they knew well (swimming) rather than something that they had never experienced, which shows that physical execution is not a mandatory requirement for observing the enhancement effect resulting from task duration knowledge. These three converging experiments suggest that task duration knowledge is strongly involved in time perception.     

Artificial grammar learning by 1-year-olds leads to specific and abstract knowledge.

Four experiments used the head-turn preference procedure to assess whether infants could extract and remember information from auditory strings produced by a miniature artificial grammar. In all four experiments, infants generalized to new structure by discriminating new grammatical strings from ungrammatical ones after less than 2 min exposure to the grammar. Infants acquired specific information about the grammar as demonstrated by the ability to discriminate new grammatical strings from those with illegal endpoints (Experiment 1). Infants also discriminated new grammatical strings from those with string-internal pairwise violations (Experiments 2 and 3). Infants in Experiment 4 abstracted beyond specific word order as demonstrated by the ability to discriminate new strings produced by their training grammar from strings produced by another grammar despite a change in vocabulary between training and test. We discuss the implications of these findings for the study of language acquisition.     

Code switching by bilinguals: Evidence against a third grammar

Bilingual code switching within sentences (as in “The towel roja was dirty”) is often observed in bilingual communities. The present study addressed two issues. First, what is the nature of the grammatical rules that underlie code switching? Second, how do bilingual speakers acquire such rules? We addressed the first issue by obtaining judgments of the grammaticality of four types of sentences containing code-switched words. Judgments of acceptability seemed to be based on two rules: (1) Code switching can occur only when the code-switched words are positioned in accord with the rules for which they are approriate lexical items; (2) code switching within word boundaries is considered ungrammatical. We addressed the second issue by exploring the effects of age and code switching experience on the grammatical judgments of bilingual children and adults. Extensive code-switching experience did not seem to be necessary for bilingual speakers to know the grammatical constraints of code switching. This suggests that the constraints of code switching are based on the integration of the grammars of the two code-switched languages rather than on the creation of a third grammar. There were developmental changes in the judgments made to the sentences. All aged subjects found sentences that violated the word-order rule (1 above) unacceptable. However, the youngest children (8- to 10-year-olds) found mixing within a word acceptable. This developmental change could be due to a change in the grammar of code switching, in the ability to make metalinguistic judgments, or in the child's general knowledge about the nature of languages.     

Reduced orthographic learning in dyslexic adult readers: Evidence from patterns of letter search

Visual letter search performance was investigated in a group of dyslexic adult readers using a task that required detection of a cued letter target embedded within a random five-letter string. Compared to a group of skilled readers, dyslexic readers were significantly slower at correctly identifying targets located in the first and second string position, illustrating significantly reduced leftward facilitation than is typically observed. Furthermore, compared to skilled readers, dyslexic readers showed reduced sensitivity to positional letter frequency. They failed to exhibit significantly faster response times to correctly detect target letters appearing in the most, compared to least, frequent letter position within five-letter words, and response times correlated with positional letter frequency only for the initial, and not the final, letter position. These results are compatible with the SERIOL (sequential encoding regulated by inputs to oscillations within letter units) model of orthographic processing proposed by Whitney and Cornelissen (2005). Furthermore, they suggest that dyslexic readers are less efficient than skilled readers at learning to extract statistical regularities from orthographic input.     

Intuitive decision making in complex situations: Somatic markers in an artificial grammar learning task

In this article, we explore the extent to which implicit learning is subtended by somatic markers, as evidenced by skin conductance measures. On each trial, subjects were asked to decide which “word” from a pair of “words” was the “correct” one. Unknown to the subjects, each “word” of a pair was constructed using a different set of rules (Grammar Aand Grammar B). A (monetary) reward was given if the subject chose the “word” from Grammar A. Choosing the Grammar B word resulted in (monetary) punishment. Skin conductance was measured during each of 100 trials. After each set of 10 trials, the subjects were asked how they selected the “correct word.” Task performance increased long before the subjects could even formulate a single relevant rule. In this preconceptual phase of the experiment, skin conductance was larger before incorrect than before correct choices. Thus, it was shown that artificial grammar learning is accompanied by a somatic marker, possibly “warning” the subject of the incorrect decision.     

The effect of action video game playing on sensorimotor learning: Evidence from a movement tracking task

Research on the impact of action video game playing has revealed performance advantages on a wide range of perceptual and cognitive tasks. It is not known, however, if playing such games confers similar advantages in sensorimotor learning. To address this issue, the present study used a manual motion-tracking task that allowed for a sensitive measure of both accuracy and improvement over time. When the target motion pattern was consistent over trials, gamers improved with a faster rate and eventually outperformed non-gamers. Performance between the two groups, however, did not differ initially. When the target motion was inconsistent, changing on every trial, results revealed no difference between gamers and non-gamers. Together, our findings suggest that video game playing confers no reliable benefit in sensorimotor control, but it does enhance sensorimotor learning, enabling superior performance in tasks with consistent and predictable structure.     

Knowing letter names and learning letter sounds: a causal connection

Two experiments tested the common assumption that knowing the letter names helps children learn basic letter-sound (grapheme-phoneme) relation because most names contain the relevant sounds. In Experiment 1 (n=45), children in an experimental group learned English letter names for letter-like symbols. Some of these names contained the corresponding letter sounds, whereas others did not. Following training, children were taught the sounds of these same "letters." Control children learned the same six letters, but with meaningful real-word labels unrelated to the sounds learned in the criterion letter-sound phase. Differences between children in the experimental and control groups indicated that letter-name knowledge had a significant impact on letter-sound learning. Furthermore, letters with names containing the relevant sound facilitated letter-sound learning, but not letters with unrelated names. The benefit of letter-name knowledge was found to depend, in part, on skill at isolating phonemes in spoken syllables. A second experiment (n=20) replicated the name-to-sound facilitation effect with a new sample of kindergarteners who participated in a fully within-subject design in which all children learned meaningless pseudoword names for letters and with phoneme class equated across related and unrelated conditions.     

Automatic behavioural responses to valence: Evidence that facial action is facilitated by evaluative processing

Are motor schemata of facial action spontaneously activated upon the processing of evaluative information? In this case, the processing of positive evaluative information should immediately trigger the motor schema of smiling, and the processing of negative information should trigger frowning. This hypothesis was tested in two experiments in which participants were required to respond to positive and negative words by either smiling or frowning. Electromyogram (EMG) activity was recorded over the brow muscle region (corrugator supercilii) and over the cheek muscle region (zygomaticus major) in order to quantify the latency of muscular response as a dependent measure. In Experiment 1 we found that participants were faster at contracting their zygomaticus muscle (which is involved in smiling) when evaluating positive words, and faster at contracting their corrugator muscle (which is involved in frowning) when evaluating negative words. In Experiment 2, participants were required to respond with the contraction of one of the two muscles whenever a word appeared on the computer screen. Again, we found that responses were faster to congruent response valence combinations than to incongruent response valence combinations. These findings support the hypothesis that evaluative processing is directly linked to motor schemata of facial muscles.     

Sequential learning in individuals with agrammatic aphasia: evidence from artificial grammar learning

We examined sequential learning in individuals with agrammatic aphasia (n = 12) and healthy age-matched participants (n = 12) using an artificial grammar. Artificial grammar acquisition, 24-hour retention, and the potential benefits of additional training were examined by administering an artificial grammar judgment test (1) immediately following auditory exposure-based training, (2) one day after training, and (3) after a second training session on the second day. An untrained control group (n = 12 healthy age-matched participants) completed the tests on the same time schedule. The trained healthy and aphasic groups showed greater sensitivity to the detection of grammatical items than the control group. No significant correlations between sequential learning and language abilities were observed among the aphasic participants. The results suggest that individuals with agrammatic aphasia show sequential learning, but the underlying processes involved in this learning may be different than for healthy adults.     

Formal notations are diagrams: Evidence from a production task

Although a general sense of the magnitude, quantity, or numerosity of objects is common in both untrained people and animals, the abilities to deal exactly with large quantities and to reason precisely in complex but well-specified situations--to behave formally, that is--are skills unique to people trained in symbolic notations. These symbolic notations typically employ complex, hierarchically embedded structures, which all extant analyses assume are constructed by concatenative, rule-based processes. The primary goal of this article is to establish, using behavioral measures on naturalistic tasks, that some of the same cognitive resources involved in representing spatial relations and proximities are also involved in representing symbolic notations--in short, that formal notations are a kind of diagram. We examined self-generated productions in the domains of handwritten arithmetic expressions and typewritten statements in a formal logic. In both tasks, we found substantial evidence for spatial representational schemes even in these highly symbolic domains.     

ADHD children outperform normal children in an artificial grammar implicit learning task: ERP and RT evidence

This study focuses on Implicit learning (IL) in children. One of the main debates in this field concerns the occurrence of IL indicators in experimental settings and its manifestation in different populations. In this research, we are looking for evidence of the occurrence of IL in normal children and in children with Attention Deficit Hyperactive Disorder (ADHD), based on the relationship between accuracy, reaction time and event-related potentials (ERPs). Our results show differences between the analyzed groups with respect to markers for electrophysiological activity and reaction time, but not for accuracy. In consequence, we suggest that research in IL should explore different indicators and their relationship with the cognitive processing levels involved. In addition, IL might involve different forms of information processing in normal children and children with ADHD. We discuss the possible impact of these findings for future research.     

Learning of event sequences is based on response-effect learning: further evidence from a serial reaction task

Four experiments provide converging evidence that serial learning in a serial reaction task is based on response-effect learning, mediated by the learning of the relations between a response and the stimulus that follows it. In Experiment 1, the authors varied the stimulus sequence and the response-stimulus relations while holding the response sequence constant. Learning effects depended on the complexity of the response-stimulus relations but not on the stimulus-stimulus relations. In Experiment 2, transfer of serial learning from 1 stimulus sequence to another was only found when both sequences had identical response-stimulus relations. In Experiment 3, a variation of the stimulus sequence alone had no effect on serial learning, whereas in Experiment 4 learning effects increased when the response-stimulus relations but not the stimulus-stimulus relations were simplified. These findings suggest that serial learning is based on mechanisms of voluntary action control.     

Information theory and artificial grammar learning: inferring grammaticality from redundancy

In artificial grammar learning experiments, participants study strings of letters constructed using a grammar and then sort novel grammatical test exemplars from novel ungrammatical ones. The ability to distinguish grammatical from ungrammatical strings is often taken as evidence that the participants have induced the rules of the grammar. We show that judgements of grammaticality are predicted by the local redundancy of the test strings, not by grammaticality itself. The prediction holds in a transfer test in which test strings involve different letters than the training strings. Local redundancy is usually confounded with grammaticality in stimuli widely used in the literature. The confounding explains why the ability to distinguish grammatical from ungrammatical strings has popularized the idea that participants have induced the rules of the grammar, when they have not. We discuss the judgement of grammaticality task in terms of attribute substitution and pattern goodness. When asked to judge grammaticality (an inaccessible attribute), participants answer an easier question about pattern goodness (an accessible attribute).     

Contextual facilitation in a letter search task depends on how the prime is processed

In a variety of situations it has been observed that the processing of a verbal stimulus is facilitated when it is preceded by an associated word. This article is concerned with determining whether such facilitation occurs automatically upon prime presentation or whether facilitation depends on the manner of processing the prime. Experiment 1 demonstrated that a letter search in a target word was facilitated when the target was preceded by either an identical or semantically associated word. If, however, a letter search was required in the prime as well as in the target (Experiment 2), the relative advantage enjoyed by targets preceded by identical-word primes disappeared. Experiment 3 replicated this loss of facilitation using semantically associated word pairs. Contextual facilitation thus appears to depend upon the mode of analysis of the prime. If the prime is analyzed as a meaningful unit, facilitation occurs. If, however, it is subjected to a more discrete, letter-by-letter analysis, the priming effect vanishes.     

Evidence for transliminality from a subliminal card-guessing task

In this experiment we sought to provide evidence for transliminality from a test of subliminal perception that was disguised as a computerised ESP card-guessing task. It was predicted that highly transliminal individuals would outperform those with low levels of transliminality when given subliminal primes or 'clues' to the correct choice of card, but not when no primes were given. In line with the prediction, higher levels of transliminality were found to be associated with a greater number of correct selections of the target card on the primed trials, but not on the unprimed trials. In addition, a positive correlation was obtained between transliminality and detection accuracy, suggesting that higher levels of transliminality are associated with a greater sensitivity to visual stimulation. The results are discussed with reference to the possibility that transliminality might offer an alternative explanation for some ostensibly psychic perceptual experiences if subliminally acquired material is wrongly attributed to psychic sources.