Separation of multiple motor memories through implicit and explicit processes

Acquisition of multiple motor skills without interference is a remarkable ability in daily life. During adaptation to opposing perturbations, a common paradigm to study this ability, each perturbation can be successfully learned when a contextual follow-through movement is associated with the direction of the perturbation. It is still unclear, however, to what extent this learning engages the cognitive explicit process and the implicit process. Here, we untangled the individual contributions of the explicit and implicit components while participants learned opposing visuomotor perturbations, with a second unperturbed follow-through movement. In Exp. 1 we replicated previous adaptation results and showed that follow-through movements also allow learning for opposing visuomotor rotations. For one group of participants in Exp. 2 we isolated strategic explicit learning, while for another group we isolated the implicit component. Our data showed that opposing perturbations could be fully learned by explicit strategies; but when strategy was restricted, distinct implicit processes contributed to learning. In Exp.3, we examined whether learning is influenced by the disparity between the follow-through contexts. We found that the location of follow-through targets had little effect on total learning, yet it led to more instances in which participants failed to learn the task. In Exp. 4, we explored the generalization capability to untrained targets. Participants showed near-flat generalization of the implicit and explicit processes. Overall, our results indicate that follow-through contextual cues might activate, in part, top-down cognitive factors that influence not only the dynamics of the explicit learning, but also the implicit process.

Some Aspects of Pedagogical Corpora

This essay focuses on the characteristics of corpora drawn from pedagogical materials and contrasts them with the properties of corpora of larger repertoires. Two case studies show pedagogical corpora to contain relatively more chromaticism, and to devote more of their probability mass to low-frequency events. This is likely due to the formatting of and motivation behind classroom materials (for example, focusing proportionately more resources on difficult concepts). I argue that my observations challenge the utility of using pedagogical corpora within research into implicit learning. I also suggest that these datasets are uniquely situated to yield insights into explicit learning, and into how musical traditions are represented in the classroom.

Investigating the Effects of Learning Tasks on Vocabulary Knowledge

<p>This thesis looks at whether different kinds of vocabulary learning tasks result in different types of word knowledge. In almost every study that has investigated the effects of tasks on vocabulary learning; the only aspect of word knowledge that was tested was meaning and form. Since researchers agree that knowing a word involves much more than knowing its meaning and form, prior research may have measured partial knowledge of only one of several aspects of knowledge. In order to determine the effects of vocabulary learning tasks, several aspects of knowledge should be tested. The experiments in this thesis investigated how vocabulary learning tasks affect both receptive and productive knowledge of five aspects of word knowledge: orthography, association, syntax, meaning and form, and grammatical functions. In the first of six experiments, the effects of incidental learning from reading and explicit learning from word pairs on word knowledge were compared. The results indicated that gains in knowledge tend to increase as the number of repetitions increases; however, partial gains from an informative context may be reduced or eliminated if followed by a less informative context. The results also showed that learning from word pairs contributed to surprisingly greater gains in all of the aspects. In the second experiment, two tasks (learning from glossed sentences, and learning from word pairs) were compared to determine the effects of context and synonymy on vocabulary knowledge. It was found that the subjects gained greater knowledge of unknown words that had high frequency synonyms than for those with less frequent synonyms. The results also indicated that a single context may have little effect on acquisition. In the third, fourth and fifth experiments, the effects of receptive and productive learning tasks on vocabulary knowledge were examined. The results indicated that productive learning from word pairs may be more effective at developing productive knowledge while receptive learning from word pairs may be more effective at increasing receptive knowledge. The sixth experiment investigated the effects of receptive and productive learning from word pairs on communication. It was found that the receptive task may be superior in improving comprehension, and the productive task may be better suited to facilitating writing. Taken as a whole, this thesis indicates that measuring multiple aspects of vocabulary knowledge both receptively and productively may provide a much more accurate assessment of the relative efficacy of vocabulary learning tasks. Moreover, it suggests that different tasks may have a different effect on vocabulary knowledge.</p>

Investigating the Effects of Learning Tasks on Vocabulary Knowledge

<p>This thesis looks at whether different kinds of vocabulary learning tasks result in different types of word knowledge. In almost every study that has investigated the effects of tasks on vocabulary learning; the only aspect of word knowledge that was tested was meaning and form. Since researchers agree that knowing a word involves much more than knowing its meaning and form, prior research may have measured partial knowledge of only one of several aspects of knowledge. In order to determine the effects of vocabulary learning tasks, several aspects of knowledge should be tested. The experiments in this thesis investigated how vocabulary learning tasks affect both receptive and productive knowledge of five aspects of word knowledge: orthography, association, syntax, meaning and form, and grammatical functions. In the first of six experiments, the effects of incidental learning from reading and explicit learning from word pairs on word knowledge were compared. The results indicated that gains in knowledge tend to increase as the number of repetitions increases; however, partial gains from an informative context may be reduced or eliminated if followed by a less informative context. The results also showed that learning from word pairs contributed to surprisingly greater gains in all of the aspects. In the second experiment, two tasks (learning from glossed sentences, and learning from word pairs) were compared to determine the effects of context and synonymy on vocabulary knowledge. It was found that the subjects gained greater knowledge of unknown words that had high frequency synonyms than for those with less frequent synonyms. The results also indicated that a single context may have little effect on acquisition. In the third, fourth and fifth experiments, the effects of receptive and productive learning tasks on vocabulary knowledge were examined. The results indicated that productive learning from word pairs may be more effective at developing productive knowledge while receptive learning from word pairs may be more effective at increasing receptive knowledge. The sixth experiment investigated the effects of receptive and productive learning from word pairs on communication. It was found that the receptive task may be superior in improving comprehension, and the productive task may be better suited to facilitating writing. Taken as a whole, this thesis indicates that measuring multiple aspects of vocabulary knowledge both receptively and productively may provide a much more accurate assessment of the relative efficacy of vocabulary learning tasks. Moreover, it suggests that different tasks may have a different effect on vocabulary knowledge.</p>

The complex relationship between conscious/unconscious learning and conscious/unconscious knowledge: The mediating effects of salience in form–meaning connections

This study investigates how implicit and explicit learning and knowledge are associated, by focusing on the salience of target form–meaning connections. The participants were engaged in incidental learning of artificial determiner systems that included grammatical rules of [± plural] (a taught rule), [± actor] (a more salient hidden rule), and [± animate] (a less salient hidden rule). They completed immediate and delayed post-tests by means of a two-alternative forced-choice task with subjective judgments of source attributions. Awareness during the learning phase was identified through analysis of thinking aloud protocols. The results did not support a one-to-one relation between either explicit learning and conscious knowledge, or implicit learning and unconscious knowledge; rather, they indicated that implicit and explicit learning are intricately linked to conscious and unconscious knowledge mediated by the salience of form–meaning connections in target items. This result also suggests the possibility of the later emergence of knowledge without any conscious awareness of it.