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.     

Cognitive-behavioral modification of coronary-prone behaviors: Proposal for a treatment model and review of the evidence

The Type A behavior pattern (TABP) has been proposed as a causal risk factor in coronary heart disease (CHD), and Cognitive-Behavioral treatment procedures have been proposed as a means of altering TABP. However, recent research suggests that only one component of TABP, hostility and anger, is the primary pathogenic factor in CHD. We review the research literature addressing the relationship of cognitive dysfunction and TABP and the relationship between cognitive dysfunction and anger expression. We then review the cognitive-behavioral therapy research literature regarding the modification of cognitive dysfunction, TABP and anger expression. While sparse, the research suggests that cognitive-behavioral treatments for anger and hostility hold promise for the treatment of individuals at risk for CHD.Jeffrey M. Lohr, Ph.D., is an Associate Professor of Psychology at the University of Arkansas-Fayetteville. His research interests are in the assessment of irrational beliefs and their association with dsyphoric motivational statesL. Kevin Hamberger, Ph.D., is an Associate Professor in the Department of Family Medicine of the Medical College of Wisconsin. His clinical and research interests are in the cognitive-behavioral treatment of male spouse abusers     

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.     

Discriminating rigid from nonrigid motion: minimum points and views

Theoretical investigations of structure from motion have demonstrated that an ideal observer can discriminate rigid from nonrigid motion from two views of as few as four points. We report three experiments that demonstrate similar abilities in human observers: In one experiment, 4 of 6 subjects made this discrimination from two views of four points; the remaining subjects required five points. Accuracy in discriminating rigid from nonrigid motion depended on the amount of nonrigidity (variance of the interpoint distances over views) in the nonrigid structure. The ability to detect a rigid group dropped sharply as noise points (points not part of the rigid group) were added to the display. We conclude that human observers do extremely well in discriminating between nonrigid and fully rigid motion, but that they do quite poorly at segregating points in a display on the basis of rigidity.     

Actual differences and stereotypical perceptions in body image and eating disturbance: A comparison of male and female heterosexual and homosexual samples

In the present study, 32 homosexual males (HMM), 32 homosexual females (HMF), 32 heterosexual males (HTM), and 32 heterosexual females (HTF) completed measures of body image disturbance and concerns with weight and dieting from five different perspectives: self, and typical homosexual male, heterosexual male, heterosexual female, and homosexual female. Participants were primarily Caucasian. Results indicated that, in general, HMMs and HTFs showed greater actual concerns with appearance, weight, and dieting, and were perceived to possess greater body image disturbance and dieting concerns compared to HTMs and HMFs. Subjects also held various stereotypic misperceptions about certain target groups such that HTFs and HMMs were predicted to possess greater body image disturbance and be more concerned with weight and dieting than was actually true. In addition, subjects made accurate predictions about HTMs overall, but were inconsistent in their predictions of HMFs on these measures. Results are discussed in terms of possible variation in the degree of importance these attributes may have for members of these four populations and how such differences may lead to an increased risk for developing eating disorders among heterosexual females and homosexual males.     

Evidencefor implicitscaling in comparative judgment

In two experiments, we examined the effects of manipulating the density of stimuli on comparison difficulty in a comparative judgment task. In Experiment 1, subjects were slower at judging the relative size of a pair when the members were adjacent items in the linear order than when the members were separated by items of intervening magnitudes. In Experiment 2, the advantage of choosing the larger rather than the smaller of two large-stimuli (e.g., the congruity effect) increased when the linear order included many small items. In contrast, the advantage of choosing the smaller of two small items increased when the linear order included many large items. The applicability of the range-frequency theory (Parducci,1965) to these results is discussed.     

Limbic networks and associative learning: II. Entorhinal contributions to spontaneous alternation, passive avoidance, and taste aversion learning

The hippocampus plays an important role in learning and memory, but the precise nature of that involvement remains uncertain. Transection of the perforant path, a primary input pathway to the hippocampus, has been shown to produce changes in reaction to novelty and acquisition of active avoidance; the nature and magnitude of these changes vary with lateral or medial perforant path damage. In a series of experiments on adult rats, the role of these pathways in spontaneous alternation, exploration, acquisition and extinction of conditioned responses, passive avoidance, and conditioned taste aversion was investigated. Lateral transection reduced exploration while medial transection facilitated acquisition of an active avoidance response; no effects were observed on any other measure. Results are discussed in terms of what perforant path damage might reveal regarding the interactions of the hippocampus with other brain regions.     

Gender differences in the relation between stressful life events and adjustment among school-aged children

The study evaluated gender differences in the relation between stressful life events and adjustment among elementary school children. In Study I, anxiety, aggression, submissive withdrawal, and life event questionnaires were completed by 63 Israeli children. The frequency of life events was associated with increased anxiety and trends toward heightened withdrawal and aggression among boys, but not girls. In Study II, 80 Israeli mothers of elementary school children completed parallel questionnaires regarding their child. As in Study I, life events were associated among boys, but not girls, with increased anxiety and a trend toward heightened withdrawal. No gender difference arose in the association for aggression. Discussion focused on the possible roots of these findings in differential patterns of stress sensitivity, resilience, and coping, and on their ramifications for the study of cross-situational gender differences.     

HOLOMOVEMENT METAPHYSICS AND THEOLOGY

Abstract. The holomovement metaphysics of David Bohm emphasizes connections and continuous change. Two general movements through space-time extend Bohm's ideas. One is that the universe was nonlocal when it started but increases in locality. (With nonlocality, two simultaneous but distant events affect each other.) The other is the opposite movement or evolution toward increasingly complex systems exhibiting internal connections and a type of nonlocality. This metaphysics produces a theology when the holomovement is a model for God. Several topics follow, including global nonlocality, God as creator, God's transcendence and immanence, and God as personal. This theology shows promise but needs further development.     

The Situational Specificity of Validities: Correcting for Statistical Artifacts Does Not Always Reduce the Trans-Situational Variability of Correlation Coefficients

Validity generalization research suggests that much of the variability in validity coefficients is due to statistical artifacts, such as sampling error. Correcting for these artifacts usually reduces the trans-situational variability in validity coefficients, but the reverse can happen. Conditions under which corrections for statistical artifacts can increase the variability in validity coefficients are described, examples of meta-analyses reporting larger corrected than observed variance in validity are cited, and implications for the situational specificity of validity coefficients are discussed. In general, the true variability in validity coefficients based on large samples is often larger than the observed variability in test validities.