Age and individual differences in visuospatial processing speed: Testing the magnification hypothesis

Forty young adults and 40 older adults performed seven visuospatial information processing tasks. Factor analyses of the response times (RTs) yielded a single principal component with a similar composition in both age samples. For both samples, regressing the mean RTs of fast and slow subgroups for the seven tasks (18 conditions) on the corresponding mean RTs for their age group accounted for 99% of the variance. Taken together, these findings suggest that individual differences in processing time were largely task independent. The magnification hypothesis, a simple mathematical model of the interaction between age and ability, is presented. This model correctly predicts the finding that in both the young and the older adult groups, individual differences increased systematically with task difficulty. The magnification hypothesis also explains the regression parameters describing individual differences among young adults and predicts correctly that equivalent parameters describe individual differences among older adults. According to the magnification hypothesis, the RTs of slower individuals are more affected by aging than those of faster individuals, and slower individuals may be more at risk with respect to other biological insults (e.g., changes in health status) as well.     

Bidirectionality of parallel process and the ego syntonic learning system

A model is presented of an ego syntonic learning system which functions through the use of the parallel process. It is proposed that a bidirectional parallel process may be observed across various teaching modalities and used to understand learning problems in a group psychotherapy training pmgram. One stream of parallel process issues from the trainees, who unconsciously act out their unresolved conflicts and unsatisfied learning needs in the training program. The second stream emanates from the training staff, whose unresolved conflicts over leadership and training philosophies interfere with optimal learning conditions for the trainees. Clinical examples illustrate this bidirectional phenomenon.An earlier version of this paper was presented at the Seventh Annual Conference of the Canadian Group Psychotherapy Association, Ste. Jovite, Quebec, October 1986.     

Age, variability, and speed: between-subjects diversity

Two independent data sets were selected to examine the interrelations among reaction time (RT), between-subject variability or diversity (SD), and age. In both data sets, a strong correlation between RT and SD was obtained. This strong correlation was not affected when age was controlled in a partial correlation analysis. On the other hand, a weaker but significant correlation was obtained between age and SD. This correlation was eliminated when RT was controlled in a partial correlation analysis. Our analyses of the two data sets also indicated that the relation between RT and SD is identical for both young and elderly groups. Thus, the greater diversity often observed in performances of older groups is a direct consequence of slowing, rather than an independent effect of advancing age.     

Computerized behavioral-data collection and analysis for improved clinical outcomes in rehabilitation

Medical rehabilitation seeks change in patient behavior. Because of the variability in behavior across individuals and the uncertainty of clinical outcomes, an appropriate model for clinical intervention across the rehabilitation disciplines is single-case design. Therefore, the rehabilitation process can be facilitated by data collection and analysis tools similar to those used in the experimental analysis of behavior. We describe a system of computerized tools for the measurement and control of parts of this clinical process.     

HIV and AIDS and “family” counselling: A systems and developmental perspective

This paper describes first, a developmental and systems/interactional conceptual model for understanding HIV and AIDS and second, outlines four basic principles of a systems model of therapeutic counselling used with people infected and affected by HIV Clinical examples are taken from the work of a team of family therapists at Bouverie Family Therapy Centre in Melbourne, Australia, to demonstrate that a systems developmental model is an appropriate therapy to assist HIV and AIDS affected people and their significant others to live with a chronic and stigmatized terminal illness.     

Semantic feature representations for normal and aphasic language

Aphasic and non-neurological patients grouped nouns on the basis of similarity of meaning. These word groupings served as input matrices for hierarchical clustering and multidimensional scaling analyses. The emergent structures suggest that, while the normal adult has a number of levels upon which to organize his lexicon, the adult aphasic's lexicon can be characterized as a set of partial entries that are tied to affective and situational data. The results also suggest that semantic feature representations derived from similarity-of-meaning judgments are of relevance in the study of factors which influence actual language performance.     

How general is general slowing? Evidence from the lexical domain

Three analyses are reported that are based on data from 19 studies using lexical tasks and a reduced version of the Hale, Myerson, and Wagstaff (1987) nonlexical data set. The results of Analysis 1 revealed that a linear function with a slope of approximately 1.5 described the relationship between the lexical decision latencies of older (65-75 years) and younger (19-29 years) adults. The results of Analysis 2, based on response latencies from 6 lexical tasks other than lexical decision, revealed a virtually identical linear relationship. In Analysis 3, it was found that performance on nonlexical tasks spanning the same range of task difficulty was described by a significantly steeper regression line with a slope of approximately 2.0. These findings suggest that although general cognitive slowing is observed in both domains, the degree of slowing is significantly greater in the nonlexical domain than in the lexical domain. In addition, these analyses demonstrate how the meta-analytic approach may be used to determine the limits to the external validity of experimental findings.     

Colic and fussing in infancy,and sensory processing at 3 to 8 years of age

The purpose of this follow‐up study was to examine whether a group of 28 clinic‐referred infants with colic, excessive crying, or both at 4 to 12 weeks demonstrated sensory processing, coping, and behavioral/attention regulation difficulties at 3 to 8 years of age. Seventy‐five percent of the sample demonstrated atypical behavioral responses to sensory experiences. Hours of fussing during infancy significantly correlated with inattention, emotional reactivity, touch processing, environmental coping, and externalizing behavior at 3 to 8 years, but not hours of crying. The most striking result was that children with more hours of early fussing showed less efficient sensory processing, poorer coping with the environment, and more attention/hyperactivity problems compared to those with less hours of fussing. Results suggest that hours of fussing rather than crying could be an early marker for infants at risk.