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Learning subgoals and methods for solving probability problems.

We hypothesize that typical example problems used in quantitative domains such as algebra and probability can be represented in terms of subgoals and methods that these problems teach learners. The "quality" of these subgoals and methods can vary, depending on the features of the examples. In addition, the likelihood of these subgoal's being recognized in novel problems and the likelihood of learners' being able to modify an old method for a new problem may be functions of the training examples learners study. In Experiment 1, subjects who studied examples predicted to teach certain subgoals were often able to recognize those subgoals in nonisomorphic transfer problems. Subjects who studied examples demonstrating two methods rather than one exhibited no advantages in transfer. Experiment 2 demonstrated that if the conditions for applying a method are highlighted in examples, learners are more likely to appropriately adapt that method in a novel problem, perhaps because they recognize that the conditions do not fully match those required for any of the old methods. Overall, the results indicate that the subgoal/method representational scheme may be useful in predicting transfer performance.

Adult↗

Empirically supported treatments in pediatric psychology: regimen adherence.

OBJECTIVE: To review empirical studies of psychological interventions for nonadherence to medical regimens for three chronic illnesses: asthma, juvenile rheumatoid arthritis (JRA), and type 1 diabetes. METHODS: The Chambless criteria for "promising," "probably efficacious," or "well-established" were applied to 8 intervention studies on asthma, 4 on JRA, and 11 on type 1 diabetes. RESULTS: For asthma, organizational strategies appear probably efficacious in promoting adherence, whereas educational and behavioral strategies appear promising. For JRA, behavioral strategies appear probably efficacious in improving adherence. For type 1 diabetes, multicomponent packages and operant learning procedures appear probably efficacious, whereas cognitive-behavioral strategies appear promising. No interventions were identified as "well-established." CONCLUSIONS: Future studies will need to develop adequate definitions of adherence, accurate methods of assessing adherence, and appropriate designs to evaluate multicomponent treatment programs to advance interventions to the "well-established" category.

Adolescent↗

Protein kinase C, learning and memory: a circular determinism between physiology and behaviour.

1. In vertebrates as in invertebrates, protein kinase C appears to have a key role in learning and memory, probably given its involvement in synaptic plasticity. 2. Hippocampal PKC in mammalians is activated by learning in a large variety of memory tasks. However, the kind of information processed, the type of task, and the dynamics of learning processes all induce differential changes in the mode of PKC activation and in its anatomy. 3. The behaviourally induced changes in PKC activity are often varying in their magnitude. Inter-individual differences in PKC basal activity are generally correlated to the ability to learn. 4. Pharmacologic activation and inhibition of brain PKC shows that PKC activation plays an important role in cognitive function. 5. Basal PKC stores characterising each individual could be determined by genetic factors and modulated through life by individual experience. 6. The issue of PKC and memory relationships is reformulated through a comprehensive interactionist model which leads to formulating some new testable predictions.

Animals↗

Vermectomy enhances parvalbumin expression and improves motor performance in weaver mutant mice: an animal model for cerebellar ataxia.

In the Weaver mutant mouse (wv/wv), an animal model for hereditary cerebellar ataxia, electrophysiological experiments have revealed a disorganized output of cerebellar Purkinje cells (the latter using GABA as an inhibitory transmitter) which, by a cascade of mechanisms, was thought to be the cause of the poor motor abilities. In Purkinje cell degeneration mice (pcd/pcd) lacking nearly all Purkinje cells and displaying milder motor deficiencies than wv, in comparison to wild-type mice, a strong increase in parvalbumin- and (co-localized with parvalbumin) glycine-immunopositive somata in the deep cerebellar and vestibular nuclei has recently been found. It was therefore intriguing to investigate whether motor performance in weaver mutants could be ameliorated by applying cerebellar lesions to eliminate the faulty output and to look for a change in transmitter weighting, indicated by a strong increase in parvalbumin-positive somata in areas (the respective target areas) which were formerly devoid of it. Ten Weaver mutants were subjected to cerebellar lesions. After removal of the vermis a total abolition of tremor, a definite improvement in the balance of affected body parts, an increase in locomotor activity when tested in an open-field matrix, and a strong increase in parvalbumin expression in Weaver mutant deep cerebellar and vestibular nuclei in comparison to wild-types have indeed been found. Increase in motor activity (or explorative behaviour) has been placed in relation to learning mechanisms. The increase in parvalbumin expression and the observed improvement in motor abilities and mechanisms probably related to learning underline the hypothesis that any change in the physiological equilibrium of the brain function by removal of input or output related to an assembly of nerve cells leads to a cascade of changes at the transmitter and neuronal level in near or distant connected brain structures.

Animals↗

Effects of phonotactic and orthotactic probabilities during fast mapping on 5-year-olds' learning to spell.

The purpose of this study was to investigate the orthographic-processing skills of typically developing 5-year-old preschool children. Of interest was whether phonotactic probabilities and/or orthotactic probabilities affected their ability to quickly learn the orthographic forms of 12 novel words. Orthographic processing was measured by the children's ability to spell and identify spellings of the novel words. Specifically, we were interested in whether (a) children quickly stored or "fast mapped" orthographic information after minimal exposure to novel words during storybook readings, (b) phonotactic and orthotactic probabilities affected orthographic fast-mapping skills, and (c) orthographic processing explained unique variance on a measure of the children's early spelling abilities. The results of this study indicated that young children quickly fast mapped orthographic information after minimal exposure to novel words, and their spelling (generation or reproduction but not recognition) was influenced by phonotactic and orthotactic probabilities. The significance of this work is that it demonstrates that preschoolers can fast map orthographic words they see onto spoken words they hear while listening to storybooks read to them and that the spelling of preschoolers is influenced uniquely by both phonological and orthographic information (probability of frequent letter and sound sequences in English words).

Child↗

Social learning by following: an analysis.

Learning by "following", probably a common means by which behaviors are socially transmitted from adults to young in many species, was analyzed. Pigeons first learned to eat from a human hand. When the hand then approached an operant key and pecked it, the pigeons followed and quickly learned to do the same, thereby demonstrating social learning. When the hand only led the birds to the area of the key, without demonstrating the key-peck response, the birds learned as rapidly as with a key-peck demonstration. Birds also learned, but less reliably and more slowly, when they could observe the hand's responses but were constrained and unable to follow. "Following" was also shown to engender very rapid learning of a more complex, two-member response chain.

Journal Article↗

Picture versus question elaboration on young children's learning of sentences containing high- and low-probability content.

The main purpose of the two experiments reported here was to compare the potency of two types of elaboration on children's learning of sentence content: The effects of partial picture adjuncts were compared to the effects produced by answering "why"-questions about the relationships specified in the sentences. Five- to seven-year-old children heard sentences of the form, subject/verb/direct object/preposition/instrument. Sentences contained either a high-probability or a low-probability instrument given the semantic context. In Experiment 1, sentences either were accompanied by a partial picture depicting the sentence action but omitting the instrument or were presented without a partial picture accompaniment. Recall was improved by provision of partial pictures at study. In Experiment 2, the sentences were accompanied by complete pictures depicting the sentence content. In both experiments, questioning significantly reduced recall of high-probability sentences, with recall of instruments affected especially negatively. Evidence is presented that insufficient attention to instruments may have been one mechanism mediating depressed recall of high- compared to low-probability instruments in the questioned conditions. In summary, partial pictures improved cued recall of sentences in this study; in contrast, all significant effects produced by answering why-questions were negative ones (i.e., later recall was reduced following interrogation at study).

Attention↗

Constructivism, the so-called semantic learning theories, and situated cognition versus the psychological learning theories.

In this paper, the perspective of situated cognition, which gave rise both to the pragmatic theories and the so-called semantic theories of learning and has probably become the most representative standpoint of constructivism, is examined. We consider the claim of situated cognition to provide alternative explanations of the learning phenomenon to those of psychology and, especially, to those of the symbolic perspective, currently predominant in cognitive psychology. The level of analysis of situated cognition (i.e., global interactive systems) is considered an inappropriate approach to the problem of learning. From our analysis, it is concluded that the pragmatic theories and the so-called semantic theories of learning which originated in situated cognition can hardly be considered alternatives to the psychological learning theories, and they are unlikely to add anything of interest to the learning theory or to contribute to the improvement of our knowledge about the learning phenomenon.

Cognition↗

5-hydroxytryptophan-induced conditioned taste aversion to ethanol in the rat.

This experiment was conducted to determine the efficacy of 5-HTP in producing conditioned taste aversions (CTAs) to ethanol in rats restricted to a one-hour daily access to fluid. Administration of 100 mg/kg of DL-5-HTP immediately following novel exposure to ethanol resulted in an aversion of such magnitude that some rats refused to consume the ethanol solution. Since ethanol was the only fluid available to these rats, they eventually died, presumably of dehydration. By comparison, LiCl administration also produced a CTA to ethanol, but no such persistent rejection was observed. Both 5-HTP and LiCl also produced CTAs when saccharin and tartaric acid solutions were used as novel fluids, but these aversions were short-lived and all rats resumed drinking. The causative factor(s) in the persistent ethanol rejection until death observed in rats treated with 5-HTP remain undetermined but the results have indicated that simple CS-UCS associative learning mechanisms are probably not a primary causative factor.

5-Hydroxytryptophan↗

Influences of early thyroid hormone manipulations: delays in pup motor and exploratory behavior are evident in adult operant performance.

The effects of thyroid hormone depletion and enhancement on litter size, survival, body mass, ambulation, quadrant crossing, home orientation, day of eye opening, and free serum T3 and T4 levels were examined in Study 1. In Study 2, the effects of the timing of prenatal insult and the level of thyroid hormone depletion on litter size, survival, body mass, and free serum T3 and T4 levels were examined. Upon the completion of Study 1, randomly selected pups were maintained on ad-libitum water and food for 2 years, and performance was evaluated on fixed and variable ratio schedules, fixed and variable interval schedules, and probability and reversal learning tasks (Study 3). In Study 4, human subjects diagnosed with and treated for either congenital hypothyroidism or congenital hyperthyroidism were tested on the operant procedures used in Study 3, as well as on a series of simple reaction time, serial timing, and conjunctive and disjunctive search tasks. Dose-dependent decreases in survival and delays in the presentation of early motor and exploratory skills were observed following thyroid hormone depletion; dose-dependent accelerations in the presentation of early motor and exploratory skills were observed following thyroid hormone enhancement. Pups that had been prenatally exposed to propylthiouracil (PTU) 1-2 years after the return of thyroid hormones to baseline levels were significantly less accurate at timing on fixed and variable interval schedules, demonstrated an inability to allocate responding on probability tasks, and committed more errors during original learning (OL) and on each reversal problem. Similar deficits were observed in follow-up tests with humans diagnosed with congenital hypothyroidism, as were deficits in serial timing and visual searching. Collectively, the present results demonstrate that the pervasive and negative effects of prenatal thyroid deficiency on early behavior are also expressed during adult operant performance.

Analysis of Variance↗