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PubMed2007

The effects of cultural learning in populations of neural networks.

Population learning can be described as the iterative Darwinian process of fitness-based selection and genetic transfer of information leading to populations of higher fitness and is often simulated using genetic algorithms. Cultural learning describes the process of information transfer between individuals in a population through non-genetic means. Cultural learning has been simulated by combining genetic algorithms and neural networks using a teacher-pupil scenario where highly fit individuals are selected as teachers and instruct the next generation. By examining the innate fitness of a population (i.e., the fitness of the population measured before any cultural learning takes place), it is possible to examine the effects of cultural learning on the population's genetic makeup. Our model explores the effect of cultural learning on a population and employs three benchmark sequential decision tasks as the evolutionary task for the population: connect-four, tic-tac-toe, and blackjack. Experiments are conducted with populations employing population learning alone and populations combining population and cultural learning. The article presents results showing the gradual transfer of knowledge from genes to the cultural process, illustrated by the simultaneous decrease in the population's innate fitness and the increase of its acquired fitness measured after learning takes place.

Algorithms↗
PubMed1996

How dependencies between successive examples affect on-line learning.

We study the dynamics of on-line learning for a large class of neural networks and learning rules, including backpropagation for multilayer perceptrons. In this paper, we focus on the case where successive examples are dependent, and we analyze how these dependencies affect the learning process. We define the representation error and the prediction error. The representation error measures how well the environment is represented by the network after learning. The prediction error is the average error that a continually learning network makes on the next example. In the neighborhood of a local minimum of the error surface, we calculate these errors. We find that the more predictable the example presentation, the higher the representation error, i.e., the less accurate the asymptotic representation of the whole environment. Furthermore we study the learning process in the presence of a plateau. Plateaus are flat spots on the error surface, which can severely slow down the learning process. In particular, they are notorious in applications with multilayer perceptrons. Our results, which are confirmed by simulations of a multilayer perceptron learning a chaotic time series using backpropagation, explain how dependencies between examples can help the learning process to escape from a plateau.

Learning↗
PubMedDate not supplied

A reconceptualization of learning disabilities via a self-organizing systems paradigm.

A dilemma exists regarding the interpretation of learning disabilities. A self-organizing systems (SOS) paradigm suggests widespread, diffuse outcomes, whereas a specific learning disability concept suggests more localized dysfunction. There may be very good reason to doubt the veridicality of the concept of a specific learning disability, not because the construct of learning disabilities itself is a frivolous concept, as some have held, but because the biological or neurological events that underlie a learning disability do not remain focal and constrained only to specific dysfunction. It is important to know whether an identified learning disability remains contained or whether processing disorders might be found in other areas. The assessment profiles of school-age children identified with nonverbal learning disabilities (NLD), assumed to have primarily right-hemispheric brain dysfunctions, and children with language-based learning disabilities (LLD), assumed to have primarily left-hemispheric brain dysfunctions, were examined to explore learning disabilities using an SOS paradigm. The pilot study reported here is used as an exemplar of how a self-organizing systems paradigm is conceptualized. Although a more comprehensive study is needed to confirm the data, this exemplar suggests that overflow into areas not typically associated with each disability subtype may occur. Concerns regarding ways of determining discrepancy for diagnostic purposes are noted, and remediation strategies designed for specific disabilities are questioned.

Adolescent↗
PubMed2003

Learning foreign vowels.

Two hypotheses have recently been put forward to account for listeners' ability to distinguish and learn contrasts between speech sounds in foreign languages. First, Best's Perceptual Assimilation Model and Flege's Speech Learning Model both predict that the ease with which a listener can tell one non-native phoneme from another varies directly with the extent to which these sounds assimilate to different native phonemes (Best, 1994; also Best, McRoberts, & Goodell, 2001; Flege, 1991). Second, Logan, Lively, & Pisoni (1991) have argued that training listeners to identify non-native phonemes teaches them sets of exemplars rather than more abstract distinctive feature values. I report here the results of three sets of experiments designed to test these hypotheses, in which American English listeners were trained to categorize German nonlow vowels. The first set of experiments show that some instances of the same contrast between German vowels are more easily discriminated than others, a result incompatible with the predictions of either Best's or Flege's models, but compatible with the alternative category recognition interpretation. The second set of experiments reveals effects of contextual and speaker variation on listeners' ability to learn [tense] but not [high] contrasts between foreign vowels, and are thus at least partly compatible with an exemplar model of foreign category learning (Pisoni, Lively, & Logan, 1994; also Nosofsky, 1986). The third set of experiments compares the predictions of Nosofsky's (1986) selective attention exemplar model of category learning with those of a feature learning model in tests of listeners' learning the natural classes to which the German vowels belong. The results are mixed: listeners learned the features that define the natural classes of [+/- high] and [+/- back] vowels, but could have learned either the feature that defines the natural classes of [+/- tense] vowels or sets of [+/- tense] exemplars. Natural classes defined by abstract distinctive feature values are thus learnable, even if their membership is phonetically polymorphous.

Adult↗
PubMed1992

Self-report of family histories of learning difficulties.

Self-reports of learning difficulties by parents of reading disabled children may be inflated because of recall bias. A retrospective study of the association between specific reading disabilities and familial reports of learning difficulties indicated the relative odds of being reading disabled for those whose relatives reported learning difficulties compared with children whose relatives did not report learning difficulties was statistically significant if fathers or siblings reported learning difficulties. No significant association was found between mothers' self-reports of learning difficulties and a diagnosis of specific learning disabilities in their children. The results support the association between specific reading disabilities and self-reported histories of academic problems in the father or siblings, but not in mothers of learning disabled children. The results suggest that reports of learning difficulties among mothers of reading disabled children may be inflated because of recall bias.

Achievement↗
PubMed2004

The neurobiology of category learning.

Many recent studies have examined the neural basis of category learning. Behavioral neuroscience results suggest that both the prefrontal cortex and the basal ganglia play important category-learning roles; neurons that develop category-specific firing properties are found in both regions, and lesions to both areas cause category-learning deficits. Similar studies indicate that the inferotemporal cortex does not mediate the learning of new categories. The cognitive neuroscience literature on category learning appears contradictory until the results are partitioned according to the type of category-learning task that was used. Three major tasks can be identified: rule based, information-integration, and prototype-distortion. Recent results are consistent with the hypotheses that (a) learning in rule-based tasks requires working memory and executive attention and is mediated by frontal-striatal circuits, (b) learning in information-integration tasks requires procedural memory and is mediated primarily within the basal ganglia, and (c) learning in prototype-distortion tasks depends on multiple memory systems, including the perceptual representation system.

Animals↗
PubMed2003

The development and implementation of a curriculum to improve clinicians' self-directed learning skills: a pilot project.

BACKGROUND: Clinicians need self-directed learning skills to maintain competency. The objective of this study was to develop and implement a curriculum to teach physicians self-directed learning skills during inpatient ward rotations. METHODS: Residents and attendings from an internal medicine residency were assigned to intervention or control groups; intervention physicians completed self-directed learning curricular exercises. RESULTS: Among the 43 intervention physicians, 21 (49%) completed pre- and post-curriculum tests; and 10 (23%) completed the one-year test. Immediately after exposure to the curriculum, the proportion of physicians defining short- and long-term learning goals increased [short-term: 1/21 (5%) to 11/21 (52%), p = 0.001; long-term: 2/21 (10%) to 15/21 (71%), p = 0.001]. There were no significant changes post-curriculum in the quantity or quality of clinical question asking. The physicians' mean self-efficacy (on a 100-point scale) improved for their abilities to develop a plan to keep up with the medical literature (59 vs. 72, p = 0.04). The effects of the curriculum on self-reported learning behaviors was maintained from the immediate post-curriculum test to the one-year post curriculum test: [short-term learning goals: 1/21 (5%) pre-, 11/21 (52%) immediately post-, and 5/10 (50%) one-year after the curriculum (p = 0.0075 for the pre- vs one-year comparison); long-term learning goals: 2/21 (10%) pre-, 15/21 (71%) immediately post-, and 7/10 (70%) one-year (p = 0.0013 for the pre- vs one-year comparison). At one-year, half of the participants reported changed learning behaviors. CONCLUSIONS: A four-week curriculum may improve self-directed learning skills.

Clinical Competence↗
PubMed2006

Relationship between resident workload and self-perceived learning on inpatient medicine wards: a longitudinal study.

BACKGROUND: Despite recent residency workload and hour limitations, little research on the relationship between workload and learning has been done. We sought to define residents' perceptions of the optimal patient workload for learning, and to determine how certain variables contribute to those perceptions. Our hypothesis was that the relationship between perceived workload and learning has a maximum point (forming a parabolic curve): that either too many or too few patients results in sub-optimal learning. METHODS: Residents on inpatient services at two academic teaching hospitals reported their team and individual patient censuses, and rated their perception of their learning; the patient acuity; case variety; and how challenged they felt. To estimate maximum learning scores, linear regression models with quadratic terms were fit on learning score. RESULTS: Resident self-perceived learning correlated with higher acuity and greater heterogeneity of case variety. The equation of census versus learning score, adjusted for perception of acuity and case mix scores, showed a parabolic curve in some cases but not in others. CONCLUSION: These data suggest that perceived resident workload is complex, and impacted by additional variables including patient acuity and heterogeneity of case variety. Parabolic curves exist for interns with regard to overall census and for senior residents with regard to new admissions on long call days.

Acute Disease↗
PubMed2005

Treating learning impairments improves memory performance in multiple sclerosis: a randomized clinical trial.

This randomized clinical trial utilized established techniques to improve new learning and memory performance in multiple sclerosis (MS) participants with learning impairment. Participants were 29 individuals with clinically definite MS with documented learning deficits, randomly assigned to the experimental or control group. The experimental group underwent eight sessions of the Story Memory Technique (SMT), while the control group participated in eight sessions of memory exercises. Neuropsychological assessment was conducted at baseline, immediately following treatment and 5 weeks later to assess outcome. When stratifying participants by degree of learning deficits, a significant treatment effect was noted. MS participants with moderate-severe impairment in learning showed a significant improvement in learning abilities when compared to controls, (t(19) =3.32, P<0.01) evident in 88% of participants in the experimental group. Little improvement was noted in MS participants with mild learning impairments. Significant self-reported improvements in memory were noted in MS participants that underwent treatment, but not those that did not undergo treatment (t(26) =2.55, P<0.01). Results indicate that learning and memory deficits in MS can be effectively treated through a memory rehabilitation program utilizing context and imagery to improve new learning. Appropriate patient selection is important, with moderately-severely impaired individuals showing significantly greater benefit from treatment.

Adult↗
PubMed2004

Genetic components of vocal learning.

Vocal learning is a rare trait. Humans depend on vocal learning to acquire spoken language, but most species that communicate acoustically have an innate repertoire of sounds that they use for information exchange. Among the few non-human species that also rely on vocal learning, songbirds have provided by far the most information for understanding this process. This article concentrates on the genetic components of vocal learning in humans and birds. We summarize the existing evidence for a genetic predisposition towards acquiring the species-specific human and avian vocal repertoires. We describe the approaches used for finding genes involved in shaping the neural circuitry required for vocal learning or in mediating the learning process itself. Special attention is given to a particular gene, FOXP2, which has been implicated in a human speech and language disorder. We have studied FoxP2 in avian vocal learners and non-learners and review evidence that links both the molecule and its close homologue FoxP1 to the development of brain regions implicated in vocal learning and to their function. FoxP2 has a characteristic expression pattern in a brain structure uniquely associated with learned vocal communication, Area X in songbirds, or its analogue in parrots and hummingbirds. In both avian song learners and non-learners FoxP2 expression predominates in sensory and sensory-motor circuits. These latter regions also express FoxP2 in mammals and reptiles. We conclude that FoxP2 is important for the building and function of brain pathways including, but not limited to, those essential for learned vocal communication.

Animals↗
PubMed2004

Cellular, circuit, and synaptic mechanisms in song learning.

Songbirds, much like humans, learn their vocal behavior, and must be able to hear both themselves and others to do so. Studies of the brain areas involved in singing and song learning could reveal the underlying neural mechanisms. Here we describe experiments that explore the properties of the songbird anterior forebrain pathway (AFP), a basal ganglia-forebrain circuit known to be critical for song learning and for adult modification of vocal output. First, neural recordings in anesthetized, juvenile birds show that auditory AFP neurons become selectively responsive to the song stimuli that are compared during sensorimotor learning. Individual AFP neurons develop tuning to the bird's own song (BOS), and in many cases to the tutor song as well, even when these stimuli are manipulated to be very different from each other. Such dual selectivity could be useful in the BOS-tutor song comparison critical to song learning. Second, simultaneous neural recordings from the AFP and its target nucleus in the song motor pathway in anesthetized adult birds reveal correlated activity that is preserved through multiple steps of the circuits for song, including the AFP. This suggests that the AFP contains highly functionally interconnected neurons, an architecture that can preserve information about the timing of firing of groups of neurons. Finally, in vitro studies show that recurrent synapses between neurons in the AFP outflow nucleus, which are expected to contribute importantly to AFP correlation, can undergo activity-dependent and timing-sensitive strengthening. This synaptic enhancement appears to be restricted to birds in the sensory critical and early sensorimotor phases of learning. Together, these studies show that the AFP contains cells that reflect learning of both BOS and tutor song, as well as developmentally regulated synaptic and circuit mechanisms well-suited to create temporally organized assemblies of such cells. Such experience-dependent sensorimotor assemblies are likely to be critical to the AFP's role in song learning. Moreover, studies of such mechanisms in this basal ganglia circuit specialized for song may shed light more generally on how basal ganglia circuits function in guiding motor learning using sensory feedback signals.

Animals↗
PubMed2003

The differential effect of PD and normal aging on early explicit sequence learning.

BACKGROUND: Motor sequence learning is abnormal in PD. However, it is not known whether this defect is present during the earliest stages of the illness or whether it reflects specific limitations in dividing attention between cognitive and motor requirements. METHODS: Fifteen patients with early stage PD and 10 age-matched and 9 younger normal controls moved the right dominant hand on a digitizing tablet to eight targets presented on a screen in synchrony with a tone at 1-second intervals. The tasks were as follows: 1) CCW--a timed-response task where targets appeared in a predictable counterclockwise order; 2) RAN--a reaction time task where targets were random and unpredictable; 3) SEQ--a task with multiple demands emphasizing explicit learning and target anticipation in which subjects learned a sequence while reaching for targets; and 4) VSEQ--subjects learned a visual sequence without moving. RESULTS: CCW and RAN yielded similar results in all groups. In patients with PD, sequence learning was the same in SEQ and VSEQ and was slower compared to both control groups. In older controls, learning was faster in VSEQ than in SEQ, whereas younger controls learned equally fast in both tasks. CONCLUSIONS: Despite normal motor execution, the initial phases of sequence learning are impaired in early PD independent of task requirements, possibly reflecting reduced working memory. Learning was slower in older than younger controls only in tasks with multiple demands, presumably due to reduced attentional resources.

Adult↗
PubMed1997

The limits of social learning: translating analysis into action.

In what respects does public-policy making reflect social learning, drawing lessons from previous experiences and from the experiences of governments in other settings? Starting with an examination of the effect of policy legacies on current policy making, I present a process model of social learning embedded within the larger policy-making process resting at the intersection of the nation's constitutional context, technological change, and political influences exogenous to social learning. The model first distinguishes between the structural and the social learning effects of policy legacies. I then conceptually divide social learning into separate streams of substantive learning and situational learning. The effect that each of these has on policy making depends on the relative position of three categories of participants in the policy-making process (experts, organized interests, and politicians), as well as on the scope of the policy issue being considered (ranging from routine change to major reform). This analysis, with reference to recent health care policy making, reveals the full extent to which social learning is often a decidedly political struggle over ideas and information in which advocates promote lessons that severe their specific interests within a given institutional context and political setting. I consider the implications of social learning for understanding likely policy responses to the rise of market forces in health care.

Economic Competition↗
PubMed2002

Learning in organizations working with telemedicine.

To investigate learning in telemedicine, qualitative interviews were conducted with 30 people working with telepsychiatry, teledermatology, a telepathology frozen-section service and tele-otolaryngology. More than 80% of the respondents said that they had learnt something new by using telemedicine. Most frequently the participants improved their knowledge of the specialty in which they were involved, but this was not the only way in which they learnt. The learning did not necessarily change behaviour, as two-thirds of the respondents felt that the learning had not permitted them to perform tasks for which they had previously needed assistance (although this varied somewhat with the type of telemedical work that respondents were engaged in). Two-thirds of respondents thought that something more could be done in telemedical work to promote their own learning, which shows the clear potential for learning by telemedicine. Learning could be promoted further by extending the use of the technology to other applications. To start working with telemedicine, initial instruction seems to be sufficient--a more extensive training programme appears unnecessary. In future, as many applications of telemedicine are implemented, health-care organizations may become important arenas for learning and leaders will have to focus on learning. The results of the present study clearly showed that working with telemedicine produces learning.

Attitude of Health Personnel↗
PubMed2001

Student teachers' beliefs about mentoring and learning to teach during teaching practice.

BACKGROUND: Various interpretations of mentor roles, by teacher educators and mentors, have been described in the literature on mentoring, while those of student teachers have received less attention. Therefore, this study focuses on student teachers' expectations of mentors and their own contributions to their learning process while they are supervised by a mentor. AIMS: The main aims of this study were: (1) bridging the research on mentoring and the research on higher education students' learning conceptions by investigating student teachers' beliefs about mentoring and learning to teach, and (2) comparing these beliefs to mentors' ones and recent views on mentoring and learning in order to make suggestions for improving learning to teach. SAMPLE: Thirty student teachers, graduates in various academic disciplines, participated. They were attending a one-year teacher education programme at Leiden University in the Netherlands. METHODS: Structured interviews with the student teachers were audio-taped. Firstly, categories of mentor roles and learning activities were derived from the data. These were linked, secondly, by their focus of attention and, thirdly, empirically by a homogeneity analysis (HOMALS). RESULTS: Six mentor roles, ten learning activities, and one regulation activity were combined in six foci: (1) affective aspects of learning to teach, (2) mentors' teaching styles, (3) assessment of student teachers' performance, (4) reflecting on students' lessons, (5) school context, and (6) self-regulation of learning. The HOMALS analysis yielded a process-product dimension. CONCLUSION: In this study, the student teachers' beliefs about mentoring were similar to those of mentors. Furthermore, a third of the student teachers expected themselves as thinking critically about their lessons, but nobody expected their mentors to explicate their practical knowledge underlying their teaching. Therefore, the articulation of this knowledge is indicated as an additional mentor role and will be elaborated.

Adult↗
PubMed2001

Changes in conceptions of learning for indigenous Australian university students.

BACKGROUND: Conceptions of learning have been investigated for students in higher education in different countries. Some studies found that students' conceptions change and develop over time while others have found no changes. Investigating conceptions of learning for Australian Aboriginal and Torres Strait Islander university students is a relatively new area of research. AIMS: This study set out to investigate conceptions of learning for Aboriginal and Torres Strait Islander university students during the first two years of their undergraduate degree courses in three Australian universities. Conceptions for each year were compared. Knowing more about learning as conceived by this cultural group may facilitate more productive higher educational experiences. SAMPLE: The sample comprised 17 students studying various degrees; 11 were male and 6 were female. Ages ranged from 18 to 48 years; mean age was 26 years. METHOD: This was a phenomenographic, longitudinal study. Individual semistructured interviews were conducted each year to ascertain students' conceptions of learning. Conceptions for second year were derived independently of those from first year. A comparative analysis then took place to determine any changes. RESULTS: These students held conceptions of learning that were similar to those of other university students; however there were some intrinsic differences. On a group level, conceptions changed somewhat over the two years as did core conceptions reported by some individual students. Some students also exhibited a greater awareness of learning during their second year that resulted in three dimensions of changed awareness. CONCLUSIONS: We believe the changed conceptions and awareness resulted from learning at university where there is some need to understand and explain phenomena in relation to theory. This brought about new understandings which allowed students to see their own learning in a relational sense.

Adolescent↗
PubMed2002

Personal understanding and target understanding: mapping influences on the outcomes of learning.

BACKGROUND: Among the many theories of learning, few have been developed specifically for education. Most have explained learning in terms of either the individual activities of the learner or the design of the learning context; yet both are important in education. Each theory applies strictly only to the context for which it was developed, and yet quite general implications for education are often suggested. AIMS: 1. To review qualitative research on learning carried out within the classroom and to identify some of the major influences on the quality of learning outcomes. 2. To develop a conceptual framework based on this research which seeks to explain differences in levels and forms of understanding. METHOD: Model building based on reviews of research on learning in schools and universities. ANALYSIS: A conceptual framework was developed from the review of the literature which emphasises the activities of both teachers and students and the influences on learning outcomes of both the individual and the social context. The framework introduces a distinction between 'target' and 'personal' understanding to draw attention to the differing ways in which curriculum designers, teachers and students define knowledge and conceptualise the teaching-learning process. It also suggests how these conceptualisations influence the level of understanding reached by students. The framework is intended to encourage teachers and curriculum designers to think about the likely effects of the tasks and conditions they are providing for students, and to consider ways of strengthening the emphasis on conceptual understanding. By drawing on research findings from both schools and universities, a way of thinking about teaching and learning is indicated which can, to some extent, be generalised across educational contexts.

Cognition↗
PubMed2003

Approaches to learning, need for cognition, and strategic flexibility among university students.

BACKGROUND: Considerable research has described students' deep and surface approaches to learning. Other research has described individuals' self-regulated learning and need for cognition. There is a need for research examining the relationships among these constructs. AIMS: This study explored relationships among approaches to learning (deep, surface), need for cognition, and three types of control of learning (adaptive, inflexible, irresolute). Theory suggested similarities among the deep approach, need for cognition, and adaptive control (aspects of self-regulated learning); and among surface, inflexible, and irresolute control (aspects of an ineffective approach to learning). One-factor and two-factor models were proposed. SAMPLE: Participants were 226 Canadian military college students. METHOD: Participants completed the following questionnaires: the Study Process Questionnaire (Biggs, 1978), the Need for Cognition Scale (Cacioppo & Petty, 1982), and the Strategic Flexibility Questionnaire (Cantwell & Moore, 1996). RESULTS: Confirmatory factor analysis supported the identification of the six scale factors. Second order confirmatory factor analysis indicated three factors representing constructs underlying these factors. CONCLUSIONS: Neither the one- nor two-factor models accounted adequately for the data. Self-regulated learning was defined by measures of the deep approach to learning, need for cognition, and adaptive control of learning. The second factor divided into one factor consisting of irresolute control, the surface approach, and negative need for cognition; and another consisting of inflexible and negative adaptive control. Substantial relationships among scales support the need for further theory development.

Adolescent↗