Multiple regression analysis of twin and sibling data

DeFries and Fulker (1985) employed a multiple regression analysis of twin data in which a cotwin's score is predicted from the proband's score, the coefficient of relationship (R = 1.0 for monozygotic twins and 0.5 for dizygotic twins), and their interaction to yield direct estimates of heritability (h²) and the proportion of variance due to common or shared environmental influences (c²). The purpose of the report is to extend this model to allow for the analysis of data from more than two familial relationships simultaneously. Data from identical twins, fraternal twins, and siblings pairs, in which one member of each pair was selected based on low reading performance, were analyzed. To analyze the data simultaneously, additional coefficients were added to the regression equation in order to differentiate shared environmental influences of twins and siblings. When the model was applied to the combined cognitive data, significant estimates for heritability were obtained in three of the six tests analyzed. The results also indicated a lack of justification for the separate twin and sibling environmental parameters, and a discussion of more parsimonious models is included.     

Things are always more complicated than you think: An open systems approach to the organizational effects of computer-automated technology

The effects of computerized office and factory automation are examined. An open systems framework is used to organize this literature. The review suggests that the benefits of technology are derived from theintermediate effects of the technology on organizational processes (the task structure, personnel system, formal structure, and informal organization). Thus, it is misleading to examine thedirect effects of computerized technology on organizational outcomes such as profits and satisfaction. Some of the effects of technology on the organizational processes are inevitable (e.g., changes in informal communication patterns). Others are determined less by the technology than by management decisions. The key to achieving success with computerized technology is matching changes in organizational processes to each other, as well as to the technology and the larger environment of the organization.Ann Majchrzak is currently Associate Professor of Human Factors at the Institute of Safety and Systems Management at the University of Southern California. She has recently written two books on the subject of technological change. Katherine J. Klein is an Assistant Professor of Industrial and Organizational Psychology in the Psychology Department of the University of Maryland at College Park.     

Perceived control and health

Perceived control (PC) is defined as thebelief that one can determine one’s own internal states and behavior, influence one’s environment, and/or bring about desired outcomes. Two important dimensions of PC are delineated: (1) whether the object of control is located in the past or the future and (2) whether the object of control is over outcome, behavior, or process. A variety of constructs and measures of PC (e.g., efficacy, attribution, and locus of control) are discussed in relation to these dimensions and selected studies are reviewed. The issues, controversies, and limits of the research on perceived control and health are addressed in terms of the antecedents and consequences of perceived control. Investigations should clearly conceptualize the object of perceived control, use measures that match the conceptualization, and when attempting to manipulate control, directly measure perceived control. The relation between PC and health outcomes is complex, and different aspects of PC may interact to affect health outcomes.     

Pharmacological effects on lateralized behavior

Sixteen student volunteers were administered a placebo and 50 mg. of chlorpromazine in tablet form, on separate occasions, two hours before testing. The three tests measured dichotic listening performance, lateral eye movements while answering questions about spatial location and verbal meaning, and lateralized facial expression while relating pleasant and unpleasant life incidents. Results showed that chlorpromazine increased the number of trials showing an ear advantage in dichotic listening. Chlorpromazine reduced lateral and increased vertical eye movements in response to the questions about spatial location and verbal meaning. Under the placebo both negative and positive emotions were expressed more in the left face. Although chlorpromazine did not affect this lateralization of negative emotions, the expression of positive emotions occurred equally often on the two sides of the face under chlorpromazine. Results may be related to an effect of chlorpromazine on the asymmetrical dopamine pathways of the brain. It is suggested that the findings may be related to a left hemisphere deficit in schizophrenia.     

Teaching social skills to emotionally disturbed adolescent inpatients

A social skills training program was evaluated with emotionally disturbed adolescent inpatients. The targeted social skills required an action or reaction within six skill areas. The program was adapted from a commercially available social skills training game that features the use of response specific feedback, self-monitoring, individualized reinforcers, and individualized performance criteria. A peer conducted the baseline and posttraining sessions while the training was conducted by an adult who had no previous interactive history with the subjects. A multiple baseline design across groups demonstrated that the program increased appropriate responding in all skill areas and that these effects generalized during the posttraining peer conducted sessions. A generalization test indicated that the subjects used their newly learned skills with a novel adult outside the training setting. The program appears quite applicable to emotionally disturbed adolescents since it targets skills in a variety of areas and employs standardized procedures to enhance replicability.     

A brainstem “mini-discharge” syndrome (anesthesia dolorosa)

Chronic pain consisting of anesthesia dolorosa secondary to bilateral interruption of the trigeminal nerves is presented as a brain stem reticular denervation syndrome. Electrothalamograms revealed fast frequency discharges in the mesothalamic prerubral and centermedian reticular formation. Mesothalamic electrical stimulation attenuated the discharges. Pain and other symptoms presumably of brainstem origin also were attenuated or abolished by therapeutic electrical stimulation twice daily. It is postulated that brain stem-represented behavioral generators are implicated by the reticular discharges in order to produce the complex symptomatology. Consequently the symptom complex is collectively identified as a brainstem “mini-discharge” syndrome. A theoretical discussion is presented to defend the thesis that reticular denervation-induced low threshold discharge system accounts for the episodic states of pain, dyskinesia, mood, and memory disturbances.