Smooth-pursuit eye movement dysfunction and liability for schizophrenia: implications for genetic modeling.

Forty-one nonpsychiatric subjects, 38 probands with schizophrenia, and 99 of their relatives were studied. Oculomotor functioning was bimodally distributed for probands and relatives. Oculomotor dysfunction was not present in all families with a schizophrenic proband. In those families in which it was present, there were significant phenotypic correlations between oculomotor functioning and schizophrenia-related characteristics. The patterns of familial resemblance in the families in whom oculomotor dysfunction was present were consistent with nonadditive genetic variance contributing both to oculomotor dysfunction and to the relationship between oculomotor dysfunction and clinical symptoms. These results suggest that schizophrenia may be etiologically heterogeneous and that oculomotor dysfunction may help to identify nonadditive genetic variance for this disorder.     

Longitudinal relationships among pain, sleep problems, and depression in rheumatoid arthritis.

This research evaluated the relationship between pain and sleep problems, and the role of pain and sleep problems in depression, in a sample of 242 patients who had been diagnosed with definite or classical rheumatoid arthritis (RA). Patients completed the Pain scale of the Arthritis Impact Measurement Scales, the Center for Epidemiological Studies Depression Scale, and self-reports of sleep disturbance at two data waves over a 2-year interval. Cross-sectional multiple regression analysis revealed that the sleep problems variable was independently associated with depression at Time 1. Longitudinal multiple regression analyses demonstrated that prior pain predicted subsequent adverse changes in sleep problems, whereas sleep problems did not affect pain over time, and prior pain and the interaction of high pain and high sleep problems were independently associated with depression from Time 1 to Time 2. These data suggest that pain may exacerbate sleeping difficulty in RA patients, and that both factors may contribute to depression over time.     

Some consequences of stimulus variability on speech processing by 2-month-old infants.

The present study explores how stimulus variability in speech production influences the 2-month-old infant's perception and memory for speech sounds. Experiment 1 focuses on the consequences of talker variability for the infant's ability to detect differences between speech sounds. When tested with high-amplitude sucking (HAS) procedure, infants who listened to versions of a syllable, such as [symbol: see text], produced by 6 male and 6 female talkers, detected a change to another syllable, such as [symbol: see text], uttered by the same group of talkers. In fact, infants exposed to multiple talkers performed as well as other infants who heard utterances produced by only a single talker. Moreover, other results showed that infants discriminate the voices of the individual talkers, although discriminating one mixed group of talkers (3 males and 3 females) from another is too difficult for them. Experiment 2 explored the consequences of talker variability on infants' memory for speech sounds. The HAS procedure was modified by introducing a 2-min delay period between the familiarization and test phases of the experiment. Talker variability impeded infants' encoding of speech sounds. Infants who heard versions of the same syllable produced by 12 different talkers did not detect a change to a new syllable produced by the same talkers after the delay period. However, infants who heard the same syllable produced by a single talker were able to detect the phonetic change after the delay. Finally, although infants who heard productions from a single talker retained information about the phonetic structure of the syllable during the delay, they apparently did not retain information about the identity of the talker. Experiment 3 reduced the range of variability across talkers and investigated whether variability interferes with retention of all speech information. Although reducing the range of variability did not lead to retention of phonetic details, infants did recognize a change in the gender of the talkers' voices (from male to female or vice versa) after a 2-min delay. Two additional experiments explored the consequences of limiting the variability to a single talker. In Experiment 4, with an immediate testing procedure, infants exposed to 12 different tokens of one syllable produced by the same talker discriminated these from 12 tokens of another syllable.(ABSTRACT TRUNCATED AT 400 WORDS)     

Hiring Practices for Human Resource Professionals: Implications for Counseling and Curriculum Development

Employers of human resource professionals described their hiring practices. This information is especially useful for counselors and for developing curricula for nonbusiness majors interested in human resource careers.     

Information Load: A Test of an Inverted-U Hypothesis with Hourly and Salaried Employees

We surveyed 714 hourly and 516 salaried employees of a midwestern telephone company to test the effects of information load on work-related outcomes. Using curvilinear regression analyses, we found support for our hypothesis that employees are less satisfied with outcomes as the load of information deviates positively or negatively from some level. We also predicted, and found, that this quadratic function was more prevalent in the hourly group than in the salaried group. Implications, future research directions, and limitations of the present study are discussed.     

Integration of the big five and circumplex approaches to trait structure.

To integrate the 5-dimensional simple-structure and circumplex models of personality, the Abridged Big Five Dimensional Circumplex (AB5C) taxonomy of personality traits was developed, consisting of the 10 circumplexes that can be formed by pitting each of the Big Five factors against one another. The model maps facets of the Big Five dimensions as blends of 2 factors. An application to data consisting of 636 self-ratings and peer ratings on 540 personality trait adjectives yielded 34 well-defined facets out of a possible 45. The AB5C solution is compared with simple-structure and lower dimensional circumplex solutions, and its integrative and corrective potential are discussed, as well as its limitations.     

Social support, depressed mood, and adjustment to stress: a genetic epidemiologic investigation.

A survey of 821 same-sex female twin pairs from a population-based registry assessed 8 dimensions of social support and social integration. Twin analyses documented significant common environmental influences on 5 of these 8 measures and significant genetic influences on 5 of the 8. A decomposition of the multiplicative association between support and a measure of stressful life experiences in predicting depressed mood--an association typically interpreted as providing evidence for a stress-buffering effect of social support--shows clearly that it is the environmental and genetic factors that cause support, rather than support itself, that buffer the effects of stress on mood in most cases. We discuss the implications of this result for future research on the relationship between social support and psychopathology.     

Information feedback and the learning multiple-degree-of-freedom activities

The influence of information feedback on the learning of a multiple-degree-of-freedom activity, the overhand throw, was investigated. During learning, feedback was presented in the form of knowledge of results, knowledge of performance, knowledge of performance with attention-focusing cues, or knowledge of performance with error-correcting transitional information. Across 12 practice sessions, performance was assessed with respect to both throwing distance and throwing form. Subjects provided with knowledge of performance along with transitional information demonstrated significant gains in throwing distance, compared with subjects receiving knowledge of performance or knowledge of results alone. Movement form ratings followed the same trend. Providing learners with cues to focus their attention on the relevant aspects of knowledge of performance or directly providing transitional information was a better aid to the acquisition of throwing form than providing knowledge of results or knowledge of performance alone. These results support the hypothesis that knowledge of results may not be the most potent form of feedback in multiple-degree-of-freedom activities and that knowledge of performance, when combined with additional information, can lead to significant gains in skill acquisition.     

Affect, personality, and social activity.

These studies examined relations between social activity and state and trait measures of Positive and Negative Affect. In Study 1 Ss completed scales relevant to 3-factor models of personality and a weekly mood and social activity questionnaire for 13 weeks. In Study 2 Ss completed measures of the 5-factor model of personality and a daily mood and social activity survey for 6-7 weeks. In within- and between-Ss analyses, socializing correlated significantly with state measures of Positive Affect and with trait measures of Extraversion/Positive Emotionality. These relations were relatively general across various types of positive affect and social events; however, specific types of social events also were differentially related to affect. In contrast, social activity had no consistent association with measures of Negative Affect or the other personality dimensions. The results support a temperamental view of Extraversion.