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At least 613 records · Page 34Linked to original sources
PubMed2003

Forward propagating reinforcement learning--biologically plausible learning method for multi-layer networks.

We introduce a biologically plausible method of implementing reinforcement learning to multi-layer neural networks. The key idea is to spatially localize the synaptic modulation induced by reinforcement signals, proceeding downstream from the initial layer to the final layer. Since reinforcement signals are known to be broadcast signals in the actual brain, we need two key assumptions, inhibitory backward connections and bypass to output units, to spatially localize the effect of delayed reinforcement without breaking the basic laws of neurophysiology.

Animals↗
PubMed1994

Learning. Neuronal dynamics and perceptual learning.

Perceptual learning is accompanied by changes in the properties of individual neurons and in the functional cortical architecture; these are observed in a number of cortical areas, over short and long time scales.

Adult↗
PubMed2002

Why aggregated learning follows the power law of practice when individual learning does not: comment on Rickard (1997, 1999), Delaney et al. (1998), and Palmeri (1999).

The power law of practice is often considered a benchmark test for theories of cognitive skill acquisition. Recently, P. F. Delaney, L. M. Reder, J. J. Staszewski, and F. E. Ritter (1998), T. J. Palmeri (1999), and T. C. Rickard (1997, 1999) have challenged its validity by showing that empirical data can systematically deviate from power-function fits. The main purpose of the present article is to extend their explanations in two ways. First, the authors empirically show that abrupt changes in performance are not necessarily based on a shift from algorithm to memory-based processing, but rather and more generally, that they occur whenever a more efficient task strategy is generated. Second, the authors show mathematically and per simulation that power functions can perfectly fit aggregated learning curves even when all underlying individual curves are discontinuous. Therefore, the authors question conclusions drawn from fits to aggregated data.

Humans↗
PubMed2006

Transfer of configural learning between the components of a preexposed stimulus compound: implications for elemental and configural models of learning.

In 2 experiments, rats received preexposure to 2 compound contexts: AB and CD for the congruent group and AC and BD for the incongruent group. Subsequently, all rats received a configural discrimination in which separate placement in contexts A or B indicated that presentations of stimulus X would be followed by food and presentations of Y would not, and separate placement in contexts C and D indicated that Y would be followed by food and X would not. In both experiments, rats in the congruent group acquired the conditional discrimination more rapidly than those in the incongruent group. These results are inconsistent with conventional associative accounts of either stimulus preexposure effects or configural learning and instead provide support for a connectionist account.

Analysis of Variance↗
PubMed1997

Impaired place learning and unimpaired cue learning in hippocampal-lesioned pigeons.

Hippocampal processing is often crucial for normal spatial learning and memory in both birds and mammals, suggesting a general similarity in avian and mammalian hippocampal function. However, few studies using birds have examined the effect of hippocampal lesions on spatial tasks analogous to those typically used with mammals. Therefore, we examined how hippocampal lesions would affect the performance of pigeons in a dry version of the water maze. Experiment 1 showed that hippocampal-lesioned birds were impaired in acquiring the location of hidden food in the maze. Experiment 2 showed that hippocampal-lesioned birds were not impaired when a single cue indicated the location of hidden food. These results support the notion that avian and mammalian hippocampal functions are quite similar, in terms of the tasks for which their processing is crucial and the tasks for which it is not.

Animals↗
PubMed1982

Cortical substrates of taste aversion learning: dorsal prepiriform (insular) lesions disrupt taste aversion learning.

The functional relation between restricted damage to ventral primary somatosensory neocortex and the ability of rats to acquire conditioned taste aversion (CTA( was examined by a combination of behavioral and neurohistological techniques. Lesions confined exclusively to the established gustatory neocortex (GN) did not disrupt CTA acquisition, nor did lesions confined to suprarhinal cortical areas ventral to the GN. Lesions that encroached on dorsal prepiriform and insular cortices produced CTA acquisition deficits and damaged a large proportion of efferent projections to the prefrontal and precentral neocortex. In a second experiment, lesions of dorsal prepiriform and insular cortices did not modify taste preference-aversion threshold to any of the four taste modalities. It is concluded tha ventral somatosensory neocortical fields, including the established GN, do not mediate CTA acquisition and that rhinal cortices ventral and posterior to the GN are preferentially involved in associative learning for tastes and illness.

Animals↗
PubMed2003

Learned associability and associative change in human causal learning.

The Mackintosh (1975) model of associative learning specifies that processing of both the cues presented on a trial and the outcome of that trial will interact to determine the amount of associative change undergone by a given cue. Experiments looking at the distribution of associative change among the elements of a reinforced compound in animal conditioning studies indicate that processing of the outcome of a trial does indeed influence associative change. The work reported here investigates the distribution of associative change among the elements of a reinforced compound in a human causal judgement paradigm, and it indicates that processing of the cues presented on a trial also plays a role in determining associative change (in terms of changes in the associability of cues as a result of experience). Taken in combination, these results provide good support for Mackintosh (1975) and the characterizations of both cue and outcome processing that it offers.

Adult↗
PubMed1988

Learning human anatomy: does learning occur during a lecture?

Information uptake during a formal lecture was evaluated using a sample of 43 second-year medical students to whom a topic on human developmental anatomy was presented. The sample was divided into two groups: Blue (group B) (21 students) and Red (group R) (22 students). Prior to the lecture, a pre-test of 20 multiple choice questions was administered to each group. The lecture was then delivered over 50 minutes. Both in its preparation and presentation, the lecture conformed to the principles of programmed instruction. After a 10-minute students' question-and-answer session, a post-test was served. For group B, this was group R's pretest while group R, in turn, received group B's pretest. No question in the pre-test was repeated in the post-test. Intergroup comparisons of pre-test scores and of post-test scores revealed non-significant differences (P greater than 0.05), thus confirming that the pre- and the post-tests were of comparable difficulty. In each group, the mean post-test score was significantly higher than the pre-test score (P less than 0.001). The pooled scores indicated that the percentage mastery of material presented during the lecture increased from -1.8% to 58.4%. These results demonstrate that significant learning can occur during a lecture prepared and delivered in accordance with sound pedagogical principles.

Anatomy↗
PubMedDate not supplied

Different kinds of information affect word learning in the preschool years: the case of part-term learning.

Two studies investigated how preschool children's interpretations of novel words as names for parts of objects were affected by 3 kinds of information: (a) whole object familiarity, (b) whole part juxtaposition, and (c) syntactic information indicating possession. Study 1 tested 3- to 4-year-olds and found that although there was evidence that all information affected children's part-term interpretations to some extent, they were most systematic when provided with 2 or more kinds of information. Study 2 adapted the procedure for use with 2.5-year-olds and found the same general pattern of results. Variations across studies were found that may reflect changes in how different kinds of information affect word learning with development.

Affect↗
PubMed1996

A cross-language comparison of vowel perception in English-learning and German-learning infants.

Studies of cross-language consonant discrimination have shown a shift from a language-general to a language-specific pattern during the first year of life. Recently, the same pattern of change was observed for English-speaking infants' discrimination of two non-native vowel contrasts (Polka and Werker, 1994). The present study was designed to provide a more direct assessment of language-specific influences on infant vowel contrast perception. In experiment 1 adults were tested on a German (non-English) contrast, /dut/ versus /dyt/, and an English (non-German) contrast, /d epsilon t/ versus /daet/. English and German adults discriminated both contrasts with high levels of accuracy in a categorial AXB task. However, results of an identification and rating task showed that, within each non-native vowel contrast, one vowel perceptually matched a native vowel category better than the other. In experiment 2 discrimination of /dut/ versus /dyt/ and /d epsilon t/ versus /daet/ was examined in English- and German-learning infants in two age groups (6-8 months and 10-12 months) using the conditioned headturn procedure. English and German infants did not differ in their discrimination of either contrast and there were no age differences in discrimination of either contrast for the German or for the English infants. However, in both language groups at both ages, there were clear differences in performance related to the direction in which the vowel change was presented to the infants. For the German contrast, discrimination was significantly poorer when the contrast changed from /dut/ to /dyt/. For the English contrast, discrimination was significantly poorer when the contrast changed from /daet/ to /d epsilon t/. The directional asymmetries observed here and in other infant vowel studies point to a language-universal perceptual pattern which suggests that vowels produced with extreme articulatory postures serve as perceptual attractors in infant vowel perception.

Adult↗
PubMedDate not supplied

The effects of an interactive instructional strategy for enhancing reading comprehension and content area learning for students with learning disabilities.

This study investigated the effectiveness of an interactive vocabulary instructional strategy, semantic-feature analysis (SFA), on the content area text comprehension of adolescents with learning disabilities. Prior to reading a social studies text, students in resource classes either completed a relationship chart as part of the SFA condition or used the dictionary to write definitions and sentences as part of the contrast condition. Passage comprehension was measured on a multiple-choice test consisting of two types of items, vocabulary and conceptual. Comprehension was measured immediately following teaching and again 6 months after teaching. Prior knowledge for the content of the passage served as a covariate. Results indicated that students in the SFA instructional condition had significantly greater measured comprehension immediately following and 6 months after initial teaching. These results are discussed in relation to concept-driven, interactive strategies for teaching content and facilitating text comprehension.

Adolescent↗
PubMedDate not supplied

The consequences of negative scaffolding for students who learn slowly--a commentary on C. Addison Stone's "The metaphor of scaffolding: its utility for the field of learning disabilities".

In this commentary, we discuss the outcomes of effective scaffolding, the processes by which successful scaffolding works, and consider implications for children with learning disabilities or below-average academic progress. Scaffolding aims at transferring responsibility for task accomplishment from a competent person to a learner. In the context of children with educational problems, we explicate our view that current practices in many schools may result in a kind of reverse-scaffolding, preventing rather than encouraging transfer of responsibility for tasks.

Child↗
PubMed2004

Learning from the problems of problem-based learning.

BACKGROUND: The last decade has witnessed a rapid expansion of biomedical knowledge. Despite this, fashions in medical education over the same period have shifted away from factual (didactic) teaching and towards contextual, or problem-based, learning (PBL). This paradigm shift has been justified by studies showing that PBL improves reasoning and communication while being associated with few if any detectable knowledge deficits. DISCUSSION: Analysis of the literature indicates that the recent rapid rise of PBL has closely paralleled the timing of the information explosion. The growing dominance of PBL could thus worsen the problems of information management in medical education via several mechanisms: first, by creating the impression that a defined spectrum of core factual knowledge suffices for clinical competence despite ongoing knowledge expansion (quality cost); second, by dissuading teachers from refining the educational utility of didactic modalities (improvement cost); and third, by reducing faculty time for developing reusable resources to impart factual knowledge more efficiently (opportunity cost). SUMMARY: These costs of PBL imply a need for strengthening the knowledge base of 21st-century medical graduates. New initiatives towards this end could include the development of more integrated cognitive techniques for facilitating the comprehension of complex data; the design of differentiated medical curricula for producing graduates with defined high-priority skill sets; and the encouragement of more cost-effective faculty teaching activities focused on the prototyping and testing of innovative commercializable educational tools.

Education, Medical↗
PubMed2000

How children with neurofibromatosis type 1 differ from "typical" learning disabled clinic attenders: nonverbal learning disabilities revisited.

To further investigate cognitive deficits in children with Neurofibromatosis Type 1 (NF-1), children with NF-1 were compared to typical learning disabled clinic attenders (LD-clinic), all of whom had reading disabilities, as well as to a group with no disabilities (NoDx). Results indicated that both the NF-1 group and LD-clinic group had reading and reading-related deficits when compared to the NoDx group; however, the NF-1 group was more globally language impaired than the LD-clinic group. In addition, the NF-1 group scored significantly lower than the LD-clinic group, but not the NoDx group, on the visuospatial measures, thus confirming that children with NF-1 have visuospatial deficits not typical of a general LD-clinic population. The NF-1 group was not impaired in comparison to the NoDx group on certain language and visuospatial tasks that were previously found to be deficits in sibling pairwise matched designs; thus, the importance of considering genetic and familial context when studying the impact of genetic disorders on cognition was demonstrated.

Attention Deficit Disorder with Hyperactivity↗
PubMed2004

[Acquisition of skills in medical ethics in learning-teaching small groups. Comparing problem-based learning with the traditional model].

BACKGROUND: Aiming to evaluate the acquisition of skills on Medical Ethics among medical students from Marilia Medical School, some of them from the small group learning-teaching method, others from traditional teaching method. METHODS: A prospective analytical study was done based on the application of questionnaires about general themes on Ethics, at two different times. RESULTS: There weren't significant differences on the skills' acquisition between the two methods. Students from late graduation years showed a significantly better performance than those from early years. The themes that presented worse results were medical secret, legal responsible consent, patient autonomy, medical prescription, medical handbook and corporative feeling in the presence of medical mistake. CONCLUSION: The most important difference between the groups was not the pedagogical pattern but the exposition time to the theme. PBL gives the chance to distribute the theme in different situations accelerating the acquisition of knowledge in Medical Ethics. It was realized that a revitalization on Medical Ethics teaching is necessary at our institution, aiming a better integration with the socio-economical situation in our country.

Adolescent↗
PubMed1979

Function of color in learning an assembly task by learning disabled adolescents.

This study examined the effect of color on responses by 20 14- to 17-yr-old learning disabled students in a probation facility to a puzzle assembly task. Prior to the task, one of two randomly constituted groups of 10 viewed a black and white film illustrating a puzzle assembly, the other group viewed an identical film of the puzzle being assembled in color. Analysis indicated that color does not enhance performance in some cases and may inhibit performance.

Adolescent↗
PubMed1988

Hemispheric dominance inferred from Your Style of Learning and Thinking on reports of Necker cube reversals and maze learning.

30 subjects volunteered from three sources: community adults (M age = 32.8, SD = 13.4), college adults (M age = 23.8, SD = 8.3), and children (M age = 9.5, SD = 1.7) and were categorized as 'left-' and 'right-dominant' by scores on Your Style of Thinking and Learning. They reported the number of Necker cube reversals perceived in 90 sec., attempted to locate four embedded figures, and blindly traversed a 16-choice point finger maze in that order. 'Right-dominant' subjects located more embedded figures and made fewer errors on the finger maze than did 'left-dominant' subjects. College adults reported more Necker cube reversals than did community adults and children, and community adults reported more reversals than did children. Confounds of performance measures with fatigue and/or practice require further research.

Adolescent↗
PubMed2004

Human use regulatory affairs advisor (HURAA): learning about research ethics with intelligent learning modules.

The Human Use Regulatory Affairs Advisor (HURAA) is a Web-based facility that provides help and training on the ethical use of human subjects in research, based on documents and regulations in United States federal agencies. HURAA has a number of standard features of conventional Web facilities and computer-based training, such as hypertext, multimedia, help modules, glossaries, archives, links to other sites, and page-turning didactic instruction. HURAA also has these intelligent features: (1) an animated conversational agent that serves as a navigational guide for the Web facility, (2) lessons with case-based and explanation-based reasoning, (3) document retrieval through natural language queries, and (4) a context-sensitive Frequently Asked Questions segment, called Point & Query. This article describes the functional learning components of HURAA, specifies its computational architecture, and summarizes empirical tests of the facility on learners.

Artificial Intelligence↗