Cognitive mechanisms in number processing and calculation: evidence from dyscalculia

This article presents a framework for the cognitive analysis of number processing and calculation. Within this framework the primary objective is the development of a model that is sufficiently detailed to serve as a basis for explaining the number-processing/calculation performance of both normal and cognitively impaired subjects. First a general model of the cognitive mechanisms for number processing and calculation is outlined. It is shown that patterns of impairments observed in brain-damaged patients support the major assumptions of the model and that the model provides a theoretically motivated framework for interpreting the deficits. A single case is then discussed in some detail, to demonstrate that through detailed analyses of impaired performance the preliminary model can be elaborated to specify not only the general architecture of the number-processing and calculation systems, but also the inner workings of specific components and the consequences of damage to these components. The article concludes with a discussion of several general issues arising from the presented arguments.     

Occupational differentiation among white men in the first decade after high school

Most research on career development is concerned with the fate of individuals, but portraits of the heterogeneity and development of whole populations or aggregates of individuals can also be useful for understanding the needs and development of different client populations. Two population-level concepts are proposed and defined: differentiation and distribution. This report then charts the rate at which occupational differentiation proceeds among 3730 young white men and investigates the personal and family attributes by which these men are distributed, or distribute themselves, to jobs. Data from the National Longitudinal (Parnes) Survey of the Labor Force Experience of Young Men are used to examine employment among men aged 16 to 28 in different levels and fields of work. Results suggest that the rate of labor force participation stabilizes in the early twenties, differentiation among men by education and the distribution of men among different broad levels and fields of work stabilize by the mid-twenties, and the sorting of men with different socioeconomic backgrounds into different occupational groups continues through the late twenties at which age it appears to have been largely completed. Discriminant analyses suggest that the distribution of men to jobs is primarily along an occupational status dimension, and secondarily according to field of work. Among the variables used in the analyses, academic achievement is the major dimension by which men are sorted or sort themselves to different jobs.     

Naive beliefs in “sophisticated” subjects: misconceptions about trajectories of objects

University students were asked to solve simple problems about the trajectories of falling objects. A majority of the students revealed a variety of misconceptions about motion. However, the few basic patterns of responses produced by the subjects suggest considerable commonality in the types of naive physical “laws” people develop on the basis of everyday experience with the world.     

An investigation of repetition and language processing in a case of conduction aphasia

A study is reported of a single case of conduction aphasia. A battery of tasks designed to investigate the parameters of the patient's severe repetition deficit is supplemented by tests of several language functions. The results provide extensive information on a wide range of the patient's language abilities and are used to evaluate the adequacy of four models that have been offered to account for conduction aphasia. An argument is made in support of the suggestion that the syndrome of conduction aphasia should be divided into two subgroups based on patients' ability to select and realize phonemes in speech output. It is concluded that the best explanation for the disorder of patients with repetition deficit but without significant speech output problems is the hypothesis that repetition ability is compromised by a pathological limitation of auditory-verbal short-term memory. This hypothesis is extended to account for the pattern of results obtained in the language tasks.     

Right-hemispheric damage and verbal problem solving behavior.

Patients with right-hemisphere damage, who ostensibly have no linguistic impairment, are relatively incapable of solving two-term series problems in which comparative adjectives in the premise and question are antonymic. This finding suggests that such verbal reasoning depends, in part, upon nonlinguistic imaginal processes subserved by the right hemisphere. In this manner, the right hemisphere is often required for the full elaboration of linguistic input.     

Modality-independent impairments in word processing in a deep dyslexic patient

An extensive study of the language abilities of one deep dyslexic patient, B.L., was undertaken. Tests of his ability to comprehend and produce words in the auditory, verbal, and graphic modalities revealed striking similarities in performance across modalities, such that the defining symptoms of deep dyslexic reading also held true for this patient's writing, repetition, and naming. A new dual-deficit model of deep dyslexia is presented which predicts that a variety of “deep dyslexic” syndromes may occur with or without modality-specific impairments.     

Decision processes in verifying category membership statements: Implications for models of semantic memory

Current models of semantic memory assume that natural categories are well-defined. Specific predictions of two such models, the Smith, Shoben, and Rips (1974a) two-stage feature comparison model and the Glass and Holyoak (1974/75) ordered search model, were tested and disconfirmed in Experiment I. We propose an alternative model postulating fuzzy categories represented as sets of characteristic properties. This model, combined with a Bayesian decision process, accounts for the results of three additional experiments, as well as for the major findings in the semantic memory literature. We argue that people verify category membership statements by assessing similarity relations between concepts rather than by using information which logically specifies the truth value of the sentence. Our data also imply that natural categories are fuzzy rather than well-defined.     

Observational assessment systems use for basic and applied research

Three observational assessment systems, the Time-Sample Behavioral Checklist, the Staff-Resident Interaction Chronograph, and the Clinical Frequencies Recording System, are shown to have remarkable utility for a wide range of basic and applied research questions. The assessment systems have already been employed to measure independent and dependent variables in a number of treatment outcome and staff training studies and as measures in more basic studies of environmental history effects for chronic mental patients. Current and planned investigations employing the observational measures are outlined. These include psychometric studies of the instruments themselves, investigations of various parameters of ongoing treatment programs, and empirical validations of proposed nosological diagnostic schemas. Finally, several metamethodological issues germaine to observational assessment, in general, are noted, including the observation vs. interpretation debate and the role of precise observational measurement in applied research contexts.The research reported in this article was supported, in part, by Public Health Service Grants MH-15553 and MH-25464 from the National Institute of Mental Health, and by grants from The Joyce Foundation, Illinois Department of Mental Health and Developmental Disabilities, and the Purdue Research Foundation.Based on a paper presented at the 87th Annual Meeting of the American Psychological Association, New York City, September 1979, as part of a symposium New Assessment systems for residential treatment, management, research, and evaluation.     

Long-term efficacy of exercise across diagnostically heterogenous mental disorders and the mediating role of affect regulation skills

BackgroundExercise interventions are efficacious in reducing disorder-specific symptoms in various mental disorders. However, little is known about long-term transdiagnostic efficacy of exercise across heterogenous mental disorders and the potential mechanisms underlying treatment effects.MethodsPhysically inactive outpatients, with depressive disorders, anxiety disorders, insomnia or attention deficit hyperactivity disorder were randomized to a standardized 12-week exercise intervention, combining moderate exercise with behavior change techniques (BCTs) (n = 38), or a passive control group (n = 36). Primary outcome was global symptom severity (Symptom Checklist-90, SCL-90-R) and secondary outcomes were self-reported exercise (Physical Activity, Exercise, and Sport Questionnaire), exercise-specific affect regulation (Physical Activity-related Health Competence Questionnaire) and depression (SCL-90-R) assessed at baseline (T1), post-treatment (T2) and one year after post-treatment (T3). Intention-to-treat analyses were conducted using linear mixed models and structural equations modeling.ResultsFrom T1 to T3, the intervention group significantly improved on global symptom severity (d = −0.43, p = .031), depression among a depressed subsample (d = −0.62, p = .014), exercise (d = 0.45, p = .011) and exercise-specific affect regulation (d = 0.44, p = .028) relative to the control group. The intervention group was more likely to reveal clinically significant changes from T1 to T3 (p = .033). Increases in exercise-specific affect regulation mediated intervention effects on global symptom severity (ß = −0.28, p = .037) and clinically significant changes (ß = −0.24, p = .042).ConclusionsThe exercise intervention showed long-term efficacy among a diagnostically heterogeneous outpatient sample and led to long-lasting exercise behavior change. Long-term increases in exercise-specific affect regulation within exercise interventions seem to be essential for long-lasting symptom reduction.