Evaluative learning in human Pavlovian conditioning: Extinct, but still there?

Previous studies of human affective learning, the acquisition of likes and dislikes, provided evidence that extinction training does not affect changes in conditional stimulus (CS) valence as indexed by paper/pencil ratings. Experiment 1 (N = 32) investigated whether this is an artifact of the CS valence assessment, which is taken in test sessions before and after training. Pleasantness ratings were collected in pre/post training tests and, for half of the participants, on-line during training. Rated unpleasantness of the CS that preceded the aversive US (CS+) increased during acquisition and decreased during extinction back to neutral. However, as in previous studies, post extinction paper/pencil ratings revealed the maintenance of rated CS+ unpleasantness. Experiment 2 (N = 34) replicated this finding for two measures of CS valence, paper/pencil and the continuous measure used during training. The present results indicate that previous reports of failures to find extinction of affective learning may reflect renewal rather than maintenance of acquired CS valence across extinction training. (C) 2003 Elsevier Science (USA). All rights reserved.

Dissonance between conceptions of learning and ways of learning for indigenous Australian university students

This article reports on a phenomenographic investigation into conceptions of learning for 15 Indigenous Australian university students over the three years of their degree courses. The ways in which they went about learning were also investigated along with the relationship between individual students' 'core' conceptions of learning and the ways in which they learned. Results indicated that their conceptions and ways of learning were similar in some respects to those found for other university students. However, some students went about learning in ways that were incongruent with the core conception of learning they held. This can be regarded as dissonance between strategies and conceptions of learning. The implications of this for teaching and learning for such students are discussed.

Learning, odour preference and flower foraging in moths

Floral volatiles play a major role in plant-insect communication. We examined the influence of two volatiles, phenylacetaldehyde and a-pinene, on the innate and learnt foraging behaviour of the moth Helicoverpa armigera. In dual-choice wind tunnel tests, adult moths flew upwind towards both volatiles, with a preference for phenylacetaldehyde. When exposure to either of these volatiles was paired with a feeding stimulus (sucrose), all moths preferred the learnt odour in the preference test. This change in preference was not seen when moths were exposed to the odour without a feeding stimulus. The learnt preference for the odour was reduced when moths were left unfed for 24 h before the preference test. We tested whether moths could discriminate between flowers that differed in a single volatile component. Moths were trained to feed on flowers that were odour-enhanced using either phenylacetaldehyde or a-pinene. Choice tests were then carried out in an outdoor flight cage, using flowers enhanced with either volatile. Moths showed a significant preference for the flower type on which they were trained. Moths that were conditioned on flowers that were not odour-enhanced showed no preference for either of the odour-enhanced flower types. The results imply that moths may be discriminating among odour profiles of individual flowers from the same species. We discuss this behaviour within the context of nectar foraging in moths and odour signalling by flowering plants.

Learning of foraging skills by fish

This chapter outlines the relationships between a number of key factors that influence learning and memory, and illustrates them by reference to studies on the foraging behaviour of fish. Learning can lead to significant improvements in foraging performance in only a few exposures, and at least some fish species are capable of adjusting their foraging strategy as patterns of patch profitability change. There is also evidence that the memory window for prey varies between fish species, and that this may be a function of environmental predictability. Convergence between behavioural ecology and comparative psychology offers promise in terms of developing more mechanistically realistic foraging models and explaining apparently 'suboptimal' patterns of behaviour. Foraging decisions involve the interplay between several distinct systems of learning and memory, including those that relate to habitat, food patches, prey types, conspecifics and predators. Fish biologists, therefore, face an interesting challenge in developing integrated accounts of fish foraging that explain how cognitive sophistication can help individual animals to deal with the complexity of the ecological context.

Genetic influences on cognitive processes associated with distraction: An event-related potential study of the slow wave

The efficiency of inhibitory control processes has been proposed as a mechanism constraining working-memory capacity. In order to investigate genetic influences on processes that may reflect interference control, event-related potential (ER-P) activity recorded at frontal sites, during distracting and nondistracting conditions of a working-memory task, in a sample of 509 twin pairs was examined. The ERP component of interest was the slow wave (SW). Considerable overlap in source of genetic influence was found, with a common genetic factor accounting for 37 - 45% of SW variance irrespective of condition. However, 3 - 8 % of SW variance in the distracting condition was influenced by an independent genetic source. These results suggest that neural responses to irrelevant and distracting information, that may disrupt working-memory performance, differ in a fundamental way from perceptual and memory-based processing in a working-memory task. Furthermore, the results are consistent with the view that cognition is a complex genetic trait influenced by numerous genes of small influence.

Multivariate genetic analysis of cognitive abilities in an adolescent twin sample

The sources of covariation among cognitive measures of Inspection Time, Choice Reaction Time, Delayed Response Speed and Accuracy, and IQ were examined in a classical twin design that included 245 monozygotic (MZ) and 298 dizygotic (DZ) twin pairs. Results indicated that a factor model comprising additive genetic and unique environmental effects was the most parsimonious. In this model, a general genetic cognitive factor emerged with factor loadings ranging from 0.28 to 0.64. Three other genetic factors explained the remaining genetic covariation between various speed and Delayed Response measures with IQ. However, a large proportion of the genetic variation in verbal (54%) and performance (25%) IQ was unrelated to these lower order cognitive measures. The independent genetic IQ variation may reflect information processes not captured by the elementary cognitive tasks, Inspection Time and Choice Reaction Time, nor our working memory task, Delayed Response. Unique environmental effects were mostly nonoverlapping, and partly represented test measurement error.

Does industry matter? Examining the role of industry structure and organizational learning in innovation and brand performance

A manager's perception of industry structure (dynamism) has the potential to impact various organizational strategies and behaviors. This may be particularly so with regard to perceptions driving organizational learning orientations and innovation based marketing strategy. The position taken here suggests that firms operating within a competitive industry tend to pursue innovative ways of performing value-creating activities, which requires the development of learning capabilities. The results of a study of SMEs suggest that market focused learning, relative to other learning capabilities plays a key role in the relationships between industry structure, innovation and brand performance. The findings also show that market focused learning and internally focused learning influence innovation and that innovation influences a brand's performance. (c) 2005 Elsevier Inc. All rights reserved.

Transient prenatal vitamin D deficiency is associated with subtle alterations in learning and memory functions in adult rats

Based on clues from epidemiology, low prenatal vitamin D has been proposed as a candidate risk factor for schizophrenia. Recent animal experiments have demonstrated that transient prenatal vitamin D deficiency is associated with persistent alterations in brain morphology and neurotrophin expression. In order to explore the utility of the vitamin D animal model of schizophrenia, we examined different types of learning and memory in adult rats exposed to transient prenatal vitamin D deficiency. Compared to control animals, the prenatally deplete animals had a significant impairment of latent inhibition, a feature often associated with schizophrenia. In addition, the deplete group was (a) significantly impaired on hole board habituation and (b) significantly better at maintaining previously learnt rules of brightness discrimination in a Y-chamber. In contrast, the prenatally deplete animals showed no impairment on the spatial learning task in the radial maze, nor on two-way active avoidance learning in the shuttle-box. The results indicate that transient prenatal vitamin D depletion in the rat is associated with subtle and discrete alterations in learning and memory. The behavioural phenotype associated with this animal model may provide insights into the neurobiological correlates of the cognitive impairments of schizophrenia. (c) 2005 Elsevier B.V. All rights reserved.

Ten Australian elementary teachers' discourse and reported pedagogical practices during cooperative learning

This article describes the types of discourse 10 Australian grade 4-6 teachers used after they had been trained to embed cooperative learning in their curriculum and to use communication skills to promote students' thinking and to scaffold their learning. One audiotaped classroom social science lesson involving cooperative learning was analyzed for each teacher. We provide vignettes from 2 teachers as they worked with groups and from 2 student groups. The data from the audiotapes showed that the teachers used a range of mediated-learning behaviors in their interactions with the children that included challenging their perspectives, asking more cognitive and metacognitive questions, and scaffolding their learning. In turn, in their interactions with each other, the children modelled many of the types of discourse they heard their teachers use. Follow-up interviews with the teachers revealed that they believed it was important to set expectations for children's group behaviors, teach the social skills students needed to deal with disagreement in groups, and establish group structures so children understood what was required both from each other and the task. The teachers reported that mixed ability and gender groups worked best and that groups should be no larger than 5 students. All teachers' programs were based on a child-centered philosophy that recognized the importance of constructivist approaches to learning and the key role interaction plays in promoting social reasoning and learning.

Copying actions and copying outcomes: Social learning through the second year

The present work documents how the logic of a model's demonstration and the communicative cues that the model provides interact with age to influence how children engage in social learning. Children at ages 12, 18, and 24 months (n = 204) watched a model open a series of boxes. Twelve-month-old subjects only copied the specific actions of the model when they were given a logical reason to do so- otherwise, they focused on reproducing the outcome of the demonstrated actions. Eighteen-month-old subjects focused on copying the outcome when the model was aloof. When the model acted socially, the subjects were as likely to focus on copying actions as outcomes, irrespective of the apparent logic of the model's behavior. Finally, 24-month-old subjects predominantly focused on copying the model's specific actions. However, they were less likely to produce the modeled outcome when the model acted nonsocially.

Costs of learning: the dynamics of mixed-prey exploitation by silver perch, Bidyanus bidyanus (Mitchell, 1838)

Although generalist predators have been reported to forage less efficiently than specialists, there is little information on the extent to which learning can improve the efficiency of mixed-prey foraging. Repeated exposure of silver perch to mixed prey (pelagic Artemia and benthic Chironomus larvae) led to substantial fluctuations in reward rate over relatively long (20-day) timescales. When perch that were familiar with a single prey type were offered two prey types simultaneously, the rate at which they captured both familiar and unfamiliar prey dropped progressively over succeeding trials. This result was not predicted by simple learning paradigms, but could be explained in terms of an interaction between learning and attention. Between-trial patterns in overall intake were complex and differed between the two prey types, but were unaffected by previous prey specialization. However, patterns of prey priority (i.e. the prey type that was preferred at the start of a trial) did vary with previous prey training. All groups of fish converged on the most profitable prey type (chironomids), but this process took 15-20 trials. In contrast, fish offered a single prey type reached asymptotic intake rates within five trials and retained high capture abilities for at least 5 weeks. Learning and memory allow fish to maximize foraging efficiency on patches of a single prey type. However, when foragers are faced with mixed prey populations, cognitive constraints associated with divided attention may impair efficiency, and this impairment can be exacerbated by experience. (c) 2005 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Evidence for retarded extinction of aversive learning in anxious children

The habituation to intense acoustic stimuli and the acquisition of differentially conditioned fear were assessed in 53 clinically anxious and 30 non-anxious control children and young adolescents. Anxious children tended to show larger electrodermal responses during habituation, but did not differ in blink startle latency or magnitude. After acquisition training, non-anxious children rated the CS + as more fear provoking and arousing than the CS- whereas the ratings of anxious children did not differ. However, anxious children rated the CS + as more fear provoking after extinction, a difference that was absent in non-anxious children. During extinction training, anxious children displayed larger blink magnitude facilitation during CS + and a trend towards larger electrodermal responses, a tendency not seen in nonanxious children. These data suggest that extinction of fear learning is retarded in anxious children. (c) 2005 Elsevier Ltd. All rights reserved.