The interaction of the explicit and the implicit in skill learning: a dual-process approach

This article explicates the interaction between implicit and explicit processes in skill learning, in contrast to the tendency of researchers to study each type in isolation. It highlights various effects of the interaction on learning (including synergy effects). The authors argue for an integrated model of skill learning that takes into account both implicit and explicit processes. Moreover, they argue for a bottom-up approach (first learning implicit knowledge and then explicit knowledge) in the integrated model. A variety of qualitative data can be accounted for by the approach. A computational model, CLARION, is then used to simulate a range of quantitative data. The results demonstrate the plausibility of the model, which provides a new perspective on skill learning.     

The emergence of words: attentional learning in form and meaning

Children improve at word learning during the 2nd year of life—sometimes dramatically. This fact has suggested a change in mechanism, from associative learning to a more referential form of learning. This article presents an associative exemplar-based model that accounts for the improvement without a change in mechanism. It provides a unified account of children's growing abilities to (a) learn a new word given only 1 or a few training trials ("fast mapping"); (b) acquire words that differ only slightly in phonological form; (c) generalize word meanings preferentially along particular dimensions, such as object shape (the "shape bias"); and (d) learn 2nd labels for already-named objects, despite a persisting resistance to doing so ("mutual exclusivity"). The model explains these improvements in terms of increased attention to relevant aspects of form and meaning, which reduces memory interference. The interaction of associations and reference in word learning is discussed.     

Arousal, valence, and memory for detail

A common finding in the emotion-memory literature is that memory is enhanced for positively arousing stimuli and negatively arousing stimuli relative to neutral stimuli. We tested the notion that post-stimulus elaboration is responsible for these effects. Post-stimulus elaboration refers to the process of thinking about an event (after its offset) more frequently or more in-depth. We tested the hypothesis by presenting participants with 36 slides depicting events that varied in arousal (low and high) and valence (positive and negative). The opportunity for elaboration was manipulated by requiring participants, during the interslide interval, to complete addition problems, simply view the addition problems, or view a blank slide. Cued recall memory was tested for central and background details. Based on the post-stimulus elaboration hypothesis it was expected that the greatest memory decline would occur for the central details of negatively and positively arousing slides when participants were required to complete addition problems (i.e., a distractor task x arousal x detail interaction). Contrary to the hypothesis, we found that filling the inter-slide interval with a distractor task decreased memory for negative stimuli compared to positive stimuli. This effect was independent of arousal. We also found that arousal increased central detail memory for positive and negative stimuli and background detail memory for positive stimuli but not for negative stimuli. This interaction was explained on the basis of pre-attentive encoding and cue utilisation. It was concluded that in order to understand the complex relationship between emotion and memory, future studies should include, as a minimum, the variables of valence, arousal, and detail.     

Plasticity and functions of the orbital frontal cortex

We compare the effects of psychoactive drugs such as morphine and amphetamine on the synaptic organization of neurons in the orbital frontal (OFC) and medial frontal (mPFC) regions in the rat. Both regions are altered chronically by exposure to intermittent doses of either drug but the effects are area-dependent. For example, whereas morphine produces increased spine density in OFC but decreased spine density in mPFC. The differential response of the OFC and mPFC to drugs is paralleled by an areal-dependent effect of gonadal hormones on these regions as well: males have greater dendritic arborization in the mPFC whereas females have a greater arborization in the OFC. We also compared the effects of neonatal injury to the OFC and mPFC on cognitive, motor, and social behaviors as well as on the anatomical organization of the remaining brain. Again, there were differential effects of the treatments to the OFC and mPFC. Neonatal OFC lesions allowed virtually complete functional recovery of cognitive and motor behaviors, which was correlated with mild abnormalities in cerebral development compared to the more severe deficits and morphological sequelae following mPFC lesions at the same ages. One exception was the effect of OFC on social behavior, which was severe regardless of whether the injury was in infancy or adulthood. It is proposed that both drug-induced and developmental abnormalities in the integrity of OFC neurons may lead to deficits in social behavior or other behavioral pathologies, possibly including depression.     

“If I didn’t write it,why would I remember it?” Effects of encoding,attention, and practice on accurate and false memory

In two experiments involving recall and recognition, we manipulated encoding strategies, attention, and practice in the Deese, Roediger, and McDermott false memory procedure. During the study of auditory word lists, participants listened to the words, wrote the words, wrote the second letter of the words, or counted backward by threes and wrote numbers in time with the words. The results from both experiments showed that, relative to the full-attention hear word condition, the divided-attention write number condition impaired accurate memory, but not false memory. In contrast, the focused-attention write word and write second letter conditions were comparable to the hear word condition in producing accurate memory, yet they were better at reducing false memory. But even after multiple study-test trials, people still falsely recalled or recognized words that they had never written during study. These results are consistent with predictions generated from fuzzy trace theory and the activation/monitoring framework.     

Incremental exercise, plasma concentrations of catecholamines, reaction time, and motor time during performance of a noncompatible choice response time task

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants (N=9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time (R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.     

Children with lesbian parents: a community study

Existing research on children with lesbian parents is limited by reliance on volunteer or convenience samples. The present study examined the quality of parent-child relationships and the socioemotional and gender development of a community sample of 7-year-old children with lesbian parents. Families were recruited through the Avon Longitudinal Study of Parents and Children, a geographic population study of 14,000 mothers and their children. Thirty-nine lesbian-mother families, 74 two-parent heterosexual families, and 60 families headed by single heterosexual mothers were compared on standardized interview and questionnaire measures administered to mothers, co-mothers/fathers, children, and teachers. Findings are in line with those of earlier investigations showing positive mother-child relationships and well-adjusted children.     

Source of arousal and memory for detail

Two questions about the relationship between arousal and memory were investigated: First, does the source of arousal influence memory, and, second, what impact does arousal have on memory for detail? In Experiment 1, physiological arousal (running or not running in place) was factorially combined with emotional arousal (viewing a neutral or an emotional slide sequence). Recognition memory was tested for gist, central detail, and background detail. Experiments 2 and 3 were similar to Experiment 1, with the exception that a cued recall task was used in Experiment 2 and physiological arousal was manipulated with stationary biking in Experiment 3. The results of these experiments indicated that physiological arousal had little impact on memory and that emotional arousal led to improvements in memory for both central and background detail. Overall, these results supported the notions that the source of arousal is an important determinant of an event’s memorability (Christianson, 1992a) and that emotional arousal serves to enhance the scope of memory (i.e., flashbulb memory; Brown &; Kulik, 1977).     

Social Identity and Perceptions of Media Persuasion: Are We Always Less Influenced Than Others?1

People typically perceive negative media content (e.g., violence) to have more impact on others than on themselves (a third-person effect). To examine the perceived effects of positive content (e.g., public-service advertisements) and the moderating role of social identities, we examined students' perceptions of the impact of AIDS advertisements on self, students (in-group), nonstudents (out-group), and people in general. Perceived self-other differences varied with the salience of student identity. Low identifiers displayed the typical third-person effect, whereas high identifiers were more willing to acknowledge impact on themselves and the student in-group. Further, when influence was normatively acceptable within the in-group, high identifiers perceived self and students (us) as more influenced than nonstudents (them). The theoretical and practical implications of this reversal in third-person perceptions are discussed.     

A partial matching theory of the mirror effect in immediate probed recognition

A set of experiments on immediate probed recognition of digit triples is reported in which the variables were list length (five, six, seven, or eight triples), the probability that a probe was old (.33, .5, or .67), and whether the digit triples were presented with an auditory component or articulatory suppression. Previous work had suggested that the false alarm (FA) rate in this paradigm was lower when auditory information was available than when it was not; this observation had led to the development of thepartial matching theory of immediate probed recognition, according to which FAs could arise not only as a result of unlucky guesses but also when new probes shared a first digit in common with a partially retained target triple. It was argued that partial memory representations were less likely following auditory presentation than following articulatory suppression. Partial matching theory is contrasted with therational response theory, according to which all FAs are unlucky guesses; partial matching theory gave a better account of the present experimental data than did rational response theory. However, a logical relationship between the two theories was suggested, a consequence of which was that rational response theory could be modified to include partial matching in such a way as to account for mirror effects, not only in unusually difficult immediate probed recognition tasks, but also in the more commonly studied mixed test list paradigm involving words of high or low frequency.