Limbic networks and associative learning: I. Entorhinal contributions to instrumental conditioning

The hippocampal formation is a highly delineated brain structure that is believed to play a prominent role in learning and memory. The present experiment evaluated the contributions of medial and lateral perforant path input to bar press-conditioning under (a) continuous and (b) differential reinforcement of low rates of responding (DRL) schedules, and (c) shuttlebox avoidance conditioning. Bilateral deafferentation of either pathway had no effect on the acquisition of bar press responses or on performance under the DRL schedule. Deafferentation of the medial pathway facilitated acquisition of avoidance responses in a manner much like the effects seen in hippocampectomized animals. It is suggested that the medial perforant path participates in the expression of correlated patterns of neuronal discharge known to develop within the hippocampus and that this “model” serves to modulate the temporal characteristics of simple conditioned reflexes. Loss of the modulatory influence of the model may affect acquisition and extinction rates. Contributions of other hippocampal circuits are discussed in relation to established deficits. Preliminary results of this experiment were presented at the second annual convention of the American Psychological Society, Dallas, Texas, June 1990.     

Substantiating psychological injury under the federal employees' compensation act

This paper examines the administration of the Federal Employees Compensation Act by the Office of Workers' Compensation Programs (OWCP). It examines compensation claims originating at a large federal agency with a psychological component as either cause or consequence of a work-related injury. Patterns of case outcomes are noted to be similar to those in other jurisdictions, and are discussed in terms of dirticdty of proof and policy preferences. Possible anomalies in the administration of the statutes are noted. The paper describes difliculties for mental health professionals attempting to substantiate psychological injuries, and addresses ethical issues related to tension between the nature of science and the requirements of administrative systems. Knowledge regarding idormational requirements and evaluative criteria used by OWCP is necessary to effectively substantiate the work-relatedness of an injury. The paper provides guidelines concerning these requirements and criteria.     

Is valentine still doubtful? A workshop model for children of divorce

We present this eight-session structured workshop format aimed at school-aged children of divorce who are considered psychologically healthy by family and teachers, in which we review the situations most frequently encountered by these families.In the workshop we offer an understanding vision of divorce while providing the children with the experience of working with therapists who are able to deal with highly troublesome issues in a caring atmosphere.Acknowledgements are expressed to Bernardita Cruz, school counselor, and Ilana Meler and Patricia Tahl, child psychologists.     

Risks,choices and behavioral treatment

Recent arguments against the use of intrusive behavioral interventions in the treatment of handicapped people are examined. The anti-aversive position was found to be based on assumptions about the negative impact of aversive procedures, and to consider only a small subset of the variables that should be taken into account when treatment decisions are made. A preliminary application of formal decision-analysis techniques that have been developed in response to other controversial technologies had a number of benefits including: (a) sharpening the distinction between scientific and social criteria; (b) sensitizing decision-makers and scientists to the range of costs, risks, and benefits associated with treatment decisions; and (c) identifying critical areas of research. Decision-analysis techniques were found to be helpful in directing scientists and policy-makers towards more informed decision-making.     

Limbic networks and associative learning: I. Entorhinal contributions to instrumental conditioning

The hippocampal formation is a highly delineated brain structure that is believed to play a prominent role in learning and memory. The present experiment evaluated the contributions of medial and lateral perforant path input to bar press-conditioning under (a) continuous and (b) differential reinforcement of low rates of responding (DRL) schedules, and (c) shuttlebox avoidance conditioning. Bilateral deafferentation of either pathway had no effect on the acquisition of bar press responses or on performance under the DRL schedule. Deafferentation of the medial pathway facilitated acquisition of avoidance responses in a manner much like the effects seen in hippocampectomized animals. It is suggested that the medial perforant path participates in the expression of correlated patterns of neuronal discharge known to develop within the hippocampus and that this “model” serves to modulate the temporal characteristics of simple conditioned reflexes. Loss of the modulatory influence of the model may affect acquisition and extinction rates. Contributions of other hippocampal circuits are discussed in relation to established deficits. Preliminary results of this experiment were presented at the second annual convention of the American Psychological Society, Dallas, Texas, June 1990.     

The Biological Findings in Post-Traumatic Stress Disorder: A Review1

In this paper the authors review the literature on biological and treatment studies of post-traumatic stress disorder (PTSD) and present current unifying hypotheses regarding the pathophysiology. The psychophysiological studies stress overarousal, while endocrine studies suggest a decreased Cortisol production in denial and low symptom states with increases in highly symptomatic states. Suggestive evidence is provided that PTSD is associated with permanent changes in brain mechanisms involving the locus coeruleus, amygdala, and the hypothalamo-pituitary-adrenal axis. Drug treatments are promising but not fully satisfactory as yet. Directions for further research are provided.     

RELATIVE EFFECTS OF WHOLE-WORD AND PHONETIC-PROMPT ERROR CORRECTION ON THE ACQUISITION AND MAINTENANCE OF SIGHT WORDS BY STUDENTS WITH DEVELOPMENTAL DISABILITIES

We used an alternating treatments design to compare the effects of two procedures for correcting student errors during sight word drills. Each of the 5 participating students with developmental disabilities was provided daily one-to-one instruction on individualized sets of 14 unknown words. Each week's new set of unknown words was divided randomly into two groups of equal size. Student errors during instruction were immediately followed by whole-word error correction (the teacher stated the complete word and the student repeated it) for one group of words and by phonetic-prompt error correction (the teacher provided phonetic prompts) for the other group of words. During instruction, all 5 students read correctly a higher percentage of whole-word corrected words than phonetic-prompt corrected words. Data from same-day tests (immediately following instruction) and next-day tests showed the students learned more words taught with whole-word error correction than they learned with phonetic-prompt error correction.     

Body figure preferences of men and women: A comparison of two generations

Inspired by the earlier work of Rozin and Fallon (1988), this study investigated some potential determinants of the most recent increase of eating disorders among women in this country. Measures of current, preferred attractive, and acceptable body images for opposite- and same-gender figures, in addition to the thinnest and heaviest figures the subjects found attractive, were obtained from the same generation cohort as these students' parents. While gender differences were found, so were cohort differences. These cohort differences speak to factors relevant to understanding why there has been such an increase in the frequency of eating disorders in Western culture since the late 1960s, especially among adolescent women. Possible implications for treatment of eating disorders are discussed. However, the authors note that further studies are needed to determine if the cohort differences found might reflect a developmental or a definite cohort effect.     

Hypothesis-testing strategies: Why two goals are better than one

An intriguing finding in the hypothesis-testing literature concerns a large increase in the proportion of subjects who discover a rule when they are asked to determine two rules rather than that rule alone. This finding is based on Wason's (1960) “2 4 6” task, in which subjects try to discover a rule (ascending numbers) by generating and testing number triples. They are initially given an example (“2, 4, 6”) of the rule that leads to overly specific hypotheses. With single-goal (SG) instructions, subjects try to discover the correct rule and are told whether each triple proposed fits the rule. With dual-goal (DG) instructions, correct and incorrect categories are labelled, respectively, as DAX and MED. Subjects try to discover both rules and are told whether each proposed triple is DAX or MED. Two explanations of why DG subjects do better at rule discovery than SG subjects are tested: the quantity of information and the testing of complementary rules using the prevalent positive-test strategy. Results support the latter explanation: DG subjects outperform SG subjects only if they know the rules are complementary, and that SG subjects' performance does not improve when required to test more triples before announcing their first rule. A third explanation, the positivity of the linguistic label of the feedback, is ruled out. Understanding the superiority of DG instructions might suggest a general method for enhancing rule discovery.     

Transcultural Counselling and Psychotherapy in the 1990s

Transcultural counselling has its origins in practice rather than theory. There still remains a unified method to develop, and extensive epidemiological and clinical research to carry out, The growing body of work in the field of mental illness and racism, however, has encouraged clinical counsellors in the UK to describe, prescribe, develop and publish their work much more widely. Some recent developments are outlined against the background of political and social changes in Britain in the nineties. Implications for research, training and service delivery are examined.