Diathesis-stress models of psychopathology: A quantitative genetic perspective

When genetics is considered in diathesis-stress models of psychopathology, it is often assumed that heredity provides the diathesis and environmental factors are responsible for the stressor. We discuss two quantitative genetic models relevant to the diathesis-stress construct. One model focuses on genotype-environment interaction, which is the usual way in which genetic influence is represented in diathesis-stress models. A second model—genotype-environment correlation—provides an alternative that represents both genetic and environmental influences relevant to the development of psychopathology. Implications of these models for clinical research are discussed.     

WHEN PREDICTIONS CREATE REALITY:

Abstract —Nelson and Dunlosky (Psychological Science, July 1991) reported that subjects making judgments of learning (JOLs) can be extremely ac curate at predicting subsequent recall performance on a paired-associate task when the JOL task is delayed for a short while after study They argued that this result Is surprising given the results of earlier research, as well as their own current experiment, indicating that JOLs are quite inaccurate when made immediately after study We note that the delayed-JOL procedure used by Nelson and Dunlosky invited covert recall practice (which was reported by their subjects) Retrieval practice is a welt-known determinant of subsequent recall Accordingly, Nelson and Dunlosky s findings can be explained by the simple assumption that people base delayed JOLs on an assessment of retrieval success which in turn influences their retrieval success on the subsequent recall test     

Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Computerized assessment in neuropsychology: A review of tests and test batteries

This article contains detailed reviews of 13 computerized neuropsychological and performance test batteries and six stand-alone computer tests. Tasks found on these instruments are described and tables illustrate which batteries employ which measures. In addition to issues of reliability and validity, special considerations apply to computerized assessment. These issues are discussed and readers are provided information to help them assess computerized tests in relation to their particular clinical and research needs. Since many computerized tests were developed as performance assessment tools, the relationship between performance and neuropsychological assessment is examined.     

Reflections upon charitable giving: A comparison of individuals from business, ‘manual’ and professional backgrounds

This paper compares three groups of individuals in their beliefs about charitable giving. Focusing upon their preferences for different kinds of needy recipients, the paper compares the views of 49 people from (a) business, (b) professional and (c) ‘manual’ backgrounds. Their justifications of need provided the basis for comparisons on the basic themes of emotional response to requests for funds, to local versus overseas aid and to the relative roles of charity and state provision. It is argued that distinctions between the groups show the need to examine specific beliefs as well as generally held ideologies about charity. In addition, a further comparison of the groups is used to argue that they exemplify differences in the actual form of the gift relationship. These differences in form show the importance of examining charitable giving within specific social contexts, as well as with reference to the various ways of raising funds.     

Delayed constructed-response identity matching improves the spelling performance of students with mental retardation

We assessed the effects of a computerized matching-to-sample procedure on the spelling performances of three students with mental retardation. Initially, the students could 1) match pictures and printed words to one another, and 2) match pictures and printed words to spoken words. However, they could not construct words to either pictures or spoken words (e.g., touch, in order, the letters s->h->o->e given the spoken-word sample Shoe). Word constructions then improved markedly after exposure to delayed constructed-response identity matching (e.g., touch the letters s->h->o->e given the printed-word sample shoe). One subject's oral and written spelling also improved. The results extend previous research by showing multiple positive effects of a computerized spelling intervention. These effects may have occurred in part because of the formation of stimulus classes among pictures, printed words, and spoken words.     

Case vignette: premature surrender

Three commentaries are offered on the following case: George, age 57, is a previously healthy man who recently underwent surgery for removal of a low-grade malignant thymoma. At the time of admission to the hospital, George stressed to the staff that he had long ago signed a "living will," which he renewed immediately after he learned of his cancer diagnosis. At the time of surgery, the tumor was found to extend into his mediastinum; although it was removable, this required revision of part of the sternum and grafting of the vessels feeding the heart chambers. Because of the resultant tissue damage and neuronal hyperactivity, George experienced postoperative episodes of cardiac arrhythmia and bronchospasm. Unanimous medical opinion was that this situation was a temporary problem that would resolve itself as the tissues healed. Until that time, however, it will be difficult to wean him from ventilatory support. When his stay in the intensive care unit became prolonged, George and his family began to insist that his status be changed to "do not resuscitate" and reminded the staff about his longstanding living will. All of this is happening despite the fact that the patient and family seemingly comprehend that although the short-term interventions are invasive, there is a high probability of a successful outcome. George's cancer prognosis is excellent, and, although he may well have an episode of life-threatening arrhythmia, he is likely to respond to resuscitation interventions. Once the immediate postoperative period is over, his potential for a long and productive life with full capacities is excellent. Consider the following questions: (a) Should George's expressed wishes be respected, or should the staff take additional steps to help him survive the postoperative period, even if that means violating his stated wishes? and (b) What steps might the staff follow in sorting through this problem?     

The twisted helix: An essay on genetic counselors,eugenics, and social responsibility

The American eugenics movement had a significant impact on American social history, and analysis of the movement illustrates the relationship among science, scientists, and society. The history of the American eugenics movement as well as more recent examples of eugenic thought and biological determinism are reviewed. The need for genetic counselors to confront eugenic issues in their own profession and in society is discussed.