Connectionism and dynamic systems: are they really different?

We propose that connectionism and dynamic systems theory are strong contenders for a general theory of development that holds true whatever the content domain. We illustrate, through our own career narratives, the origins of these theories in motor and language development. We situate connectionism and dynamic systems among other classic and contemporary theories and conclude that, although there are meaningful differences, these differences pale in relation to the shared assumptions about the fundamental processes and mechanisms of change.     

Career orientations of senior executives and their implications for careers guidance

The development of career theory has given little attention to mid-career adults relative to that given to school leavers and young adults. Furthermore, in looking at adult careers the focus has primarily been on the objective patterns of career movements rather than on subjective aspects of career. As objective careers become less easily measured, with the disappearance of clear career ladders, the importance of the subjective career increases. In a questionnaire study of senior executives (n = 132) who undertook a formal counselling programme, there was no evidence of any change in expectations of future employing organisations, or the career signals they held important. Post-counselling clients rated themselves more highly than pre-counselling clients on their knowledge and confidence, their self awareness in regard to careers, their ability to negotiate career change and their attribution of career progress to their own personal qualities. The implications of these findings for careers counselling practice, and for the skills of career management, are discussed.     

The perception of identity by 6 1/2-month-old infants.

In Study 1, sixteen 6 1/2-month-olds were habituated to a Reversible stimulus (an upright face that could be perceived as an entirely different upright face when it was rotated 180 degrees) and to a Nonreversible stimulus (a face that could be perceived as upright in only one orientation). Following habituation for each type of stimulus, test trials paired the habituated face with a novel stimulus (an inversion of the same face). For both Reversible and Nonreversible stimuli, the physical difference between the old and new test stimuli was the same (a 180 degrees rotation); however, infants devoted more visual attention to the 180 degrees rotation only when it was a Reversible face, suggesting that the identity change was detected. Experiment 2 ruled out the explanation that infants might have failed to dishabituate to the inversion of the Nonreversible stimulus because they could not remember it. Results are interpreted as evidence that 6 1/2-month-old infants are not limited to face recognition based on similarity in pattern arrangement alone, but are capable of processing faces at a representational level.     

Continuous self-recording of epigastric pain with two rating scales: Compliance,authenticity, reliability,and sensitivity

The present study compared two self-recording scales: VAS (Visual Analogue Scale) and DIBS (Duration, Intensity, Behavior Scale) with respect to compliance, authenticity, sensitivity, and reliability using a population of 32 patients with chronic epigastric pain. Compliance, authenticity, and sensitivity data revealed no significant differences between the two scales. With respect to reliability, high temporal stability coefficients were found for pain intensity over a 2-day period, for pain duration, and for a pain index calculated from DIBS. DIBS pain intensity data showed a greater temporal stability than VAS. Since DIBS yields more clinically useful information without suffering deficits in compliance, authenticity, or reliability, it appears to be a preferable instrument for monitoring chronic pain.     

A maximum likelihood procedure for the analysis of group and individual data in aphasia research.

The limitations inherent in group versus case studies appear to lie in a complementary distribution, underscoring the importance of combining both strategies within a single research program. However, this compromise approach requires analytic tools that permit us to combine and evaluate individual and group data in a common format. Maximum likelihood estimation (MLE) belongs to a family of procedures for determining goodness of fit. MLE can be used in conjunction with a linear or nonlinear model of the way that sources of information combine to determine a given behavioral outcome; such models can be used to estimate the distance between two groups, the degree to which an individual case deviates from a given empirically or theoretically defined group profile, and the degree to which one individual case resembles another. We offer a demonstration of how MLE can be used to evaluate group and individual profiles, in a cross-linguistic study of sentence comprehension in nonfluent aphasic speakers of English, Italian, and German. This includes a demonstration in which the MLE models for each language are "lesioned" to simulate several competing accounts of receptive agrammatism.     

Human figure drawings of gender-problem and school-problem boys

In this study 19 boys aged 4 through 13 years referred for gender problems were compared with 35 similar-aged boys referred for school problems on variables derived from sets of human figure drawings. The results indicated that gender-problem boys, relative to school-problem boys, were more likely to draw female figures in response to a Draw-a-Person (DAP) instruction, were more likely to draw figures with good rather than average body proportion, tended to draw more articles of clothing on their figures, and tended to draw their female figures larger than their male figures. There were no differences between the groups in the frequency of emotional disturbance indicators, frequency of age-expected or age-exceptional figure details, and total number of body features. These results are discussed in terms of their implications for the validation of the DAP procedure, their contribution to an understanding of boyhood effeminacy, and their implications for the role of the DAP test as a clinical assessment procedure only in conjunction with other sources of information.     

Comprehension in aphasia: a cross-linguistic study

Broca's aphasics and normal controls were tested to determine relative sparing and impairment of word order, grammatical morphology, and semantic information in a sentence interpretation task. Patients were native speakers of English, German, or Italian, languages that vary drastically in the "cue validity" or information value of these three sources of information. Word order was selectively spared while grammatical morphology was selectively impaired in all three languages. Nevertheless, language-specific patterns of sentence interpretation remained in Broca's aphasics, even within the impaired morphological component, supporting an interpretation in terms of "accessing" rather than a "loss." Testing with Wernicke's aphasics, anomics, and some additional age-matched controls suggested that the selective vulnerability of morphology is not specific to agrammatic patients, at least in this paradigm.     

Bilingual Performance on the Boston Naming Test: Preliminary Norms in Spanish and English

A total of 100 young educated bilingual adults were administered the Boston Naming Test (BNT) (Kaplan, Goodglass, & Weintraub, 1983) in both Spanish and English. Three group performance scores were obtained: English only, Spanish only, and a composite score indicating the total number of items correctly named independent of language. The scores for the entire group were significantly greater in English than in Spanish. An additional set of analyses explored individual differences in picture naming performance across the two languages as measured by the BNT. For a subset of the larger group (n= 25) there were significant differences in composite over single language scoring, but no significant differences between Spanish and English. Item analyses of correct responses were conducted in both languages to explore the construct validity of the standardized administration of the BNT with this population. There was much greater variability in responses over the Spanish items for this bilingual group. The results of a correlation analysis of information obtained from the initial questionnaire with the BNT scores in each language is also reported. The practical implications of this preliminary bilingual BNT normative data are discussed.     

NT-3 facilitates hippocampal plasticity and learning and memory by regulating neurogenesis

In the adult brain, the expression of NT-3 is largely confined to the hippocampal dentate gyrus (DG), an area exhibiting significant neurogenesis. Using a conditional mutant line in which the NT-3 gene is deleted in the brain, we investigated the role of NT-3 in adult neurogenesis, hippocampal plasticity, and memory. Bromodeoxyuridine (BrdU)-labeling experiments demonstrated that differentiation, rather than proliferation, of the neuronal precursor cells (NPCs) was significantly impaired in DG lacking NT-3. Triple labeling for BrdU, the neuronal marker NeuN, and the glial marker GFAP indicated that NT-3 affects the number of newly differentiated neurons, but not glia, in DG. Field recordings revealed a selective impairment in long-term potentiation (LTP) in the lateral, but not medial perforant path-granule neuron synapses. In parallel, the NT-3 mutant mice exhibited deficits in spatial memory tasks. In addition to identifying a novel role for NT-3 in adult NPC differentiation in vivo, our study provides a potential link between neurogenesis, dentate LTP, and spatial memory.