Expert systems: A cognitive science perspective

The theory and technology of knowledge-based systems are intrinsically interdisciplinary and are closely related to the formalisms of cognitive psychology. In this paper, strategies of incorporating intelligence into a computer program are described along with a common architecture for expert systems, including choices of representation and inferential methods. The history of the field is traced from its origins in metamathematics and Newell and Simon’s (1961) GENERAL PROBLEM SOLVER to the Stanford Heuristic Programming Project that produced DENDRAL and MYCIN (Buchanan & Shortliffe, 1984). MYCIN gave rise to EMYCIN and a shell technology that has radically reduced the development time and cost of expert systems. Methodology and concepts are illustrated by transactions with a shell developed for graduate education and a demonstration knowledge base for the diagnosis of senile dementia. Knowledge-based systems and conventional programs are compared with respect to formalisms employed, applications, program characteristics, procedures supplied by the development environment, consistency, certainty, flexibility, and programmer’s viewpoint. The technology raises basic questions for cognitive psychology concerning knowledge and expertise.     

Images of midlife development among young,middle-aged,and older adults

This study examined patterns of perceived change across adulthood in a sample of 121 young (M age=19.8 years), middle-aged (M age=47.9 years) and older (M age=74.6 years) adults. Subjects rated amount of stress in life domains, salience of life course issues, and nature of personal attributes for young, middle-aged, and older targets. Seven prototypical patterns of perceived change were found. Midlife was seen as a period with many responsibilities, increased stress in several domains, and little time for leisure, but also as a peak in competence, ability to handle stress, sense of control, productivity, and social responsibility. The findings are discussed in terms of losses, which were seen primarily in the physical realm, and gains, which were mainly seen in the psychological and social realms.     

Rethinking the gender identity crossover hypothesis: A test of a new model

Both self-report and projective assessment techniques were used to examine whether there exists a gender identity crossover at midlife such that men develop a communal or affiliative orientation and women become more interested in agency and power. A sample of 150 predominantly Caucasian men and women ages 24–84 were divided into three age groups for comparison: (1) young (ages 20–39); (2) middle-aged (ages 40–65); and (3) old (ages 66–84). Measures included six pictures from the Thematic Apperception Test, which were coded for achievement, power, intimacy, and affiliation needs, and the Goldberg 50-Bipolar, from which items were selected to derive agency and communion scales. Middle-aged men were lower in the need for power and higher in the need for affiliation than were younger men; there were no age differences in self attributions of agency and communion. Results are discussed in terms of the traditionality of the men and the nontraditionality of the women with respect to work and family roles.This research was supported in part by grants to Margie Lachman from the John D. and Catherine T. MacArthur Foundation Research Network on Successful Midlife Development and the National Institute on Aging (AG06038).     

A Genome‐Wide Scan for Eysenckian Personality Dimensions in Adolescent Twin Sibships: Psychoticism,Extraversion, Neuroticism,and Lie

ABSTRACT We report the first genome‐wide scan of adolescent personality. We conducted a genome‐wide scan to detect linkage for measures of adolescent Psychoticism, Extraversion, Neuroticism, and Lie from the Junior Eysenck Personality Questionnaire. Data are based on 1,280 genotyped Australian adolescent twins and their siblings. The highest linkage peaks were found on chromosomes 16 and 19 for Neuroticism, on chromosomes 1, 7, 10, 13 m, and 18 for Psychoticism, and on chromosomes 2 and 3 for Extraversion.     

Cognitive Performance and the Role of Control Beliefs in Midlife

Midlife has been touted as being a time of peak performance in many different areas of functioning. In the present study, we investigated whether this was true for cognitive functioning on tasks assessing speed, reasoning, short-term memory, and vocabulary. We also explored the extent to which levels of cognitive functioning could be attributed to individual differences in general control beliefs. Middle-aged adults showed little or no cognitive declines on speed, reasoning, and short-term memory measures relative to the young and outperformed the young on vocabulary. Relative to the elderly, middle-aged adults scored higher on all tasks except vocabulary, for which there were no differences. Adults in midlife, on the other hand, had lower scores on measures of general control beliefs compared to younger adults. Thus, although midlife is a time of high cognitive functioning, it is also a time of lower beliefs about control. To investigate the relationship between control beliefs and cognitive performance, we used structural equation modeling. The models showed that for adults in midlife, control beliefs were predictive of performance but only for the reasoning task after background variables were considered. Specifically, high levels of control beliefs were associated with better cognitive performance. More work is needed to identify mediational processes linking control beliefs and cognitive performance for various age groups and to determine whether some cognitive processes are more controllable than others.     

Factorial structure and age-related psychometrics of the MIDUS personality adjective items across the life span

The present study addresses issues of measurement invariance and comparability of factor parameters of Big Five personality adjective items across age. Data from the Midlife in the United States (MIDUS) survey were used to investigate age-related developmental psychometrics of the MIDUS personality adjective items in 2 large cross-sectional samples (exploratory sample: N = 862; analysis sample: N = 3,000). After having established and replicated a comprehensive 5-factor structure of the measure, increasing levels of measurement invariance were tested across 10 age groups. Results indicate that the measure demonstrates strict measurement invariance in terms of number of factors and factor loadings. Also, we found that factor variances and covariances were equal across age groups. By contrast, a number of age-related factor mean differences emerged. The practical implications of these results are discussed, and future research is suggested.     

When bad things happen to older people: age differences in attributional style

This study expanded on earlier attributional work with the elderly by examining age differences in the generality, as well as the locus and stability, of causes for bad events and the relationship of these attributions to self-reported health. One hundred twenty young (mean age = 18.3) and elderly (mean age = 74.39) adults rated the internality, stability, and globality of causes for good and bad events using the Attributional Style Questionnaire (Peterson et al., 1982). Older adults were more likely than younger adults to see bad events as being due to stable and specific factors. Older adults who attributed negative outcomes to more internal and global factors also reported their health to be poorer than that of others.     

A PRELIMINARY EVALUATION OF EMPIRICALLY DERIVED CONSEQUENCES FOR THE TREATMENT OF PICA

Individualized treatment packages were developed for 3 children with high-rate severe pica using a discrimination training paradigm and a behavioral assessment-based procedure known as empirically derived consequences. Children received empirically derived reinforcers for eating under appropriate stimulus conditions (i.e., eating food only from a plate and placemat that served as a discriminative stimulus) and empirically derived punishers for attempts to engage in pica. This treatment package resulted in marked reductions in pica and an increase in appropriate eating for all 3 children in a “baited” analogue condition. In addition, low rates of pica were maintained for 9 months for all 3 children. These results suggest that treatment effectiveness may be enhanced when behavioral assessment data are used to identify potent consequences.