A simultaneous test of the relationship between identified psychosocial risk factors and recurrent events in coronary artery disease patients

Psychosocial factors are increasingly recognized as risk indicators for coronary artery disease (CAD) prognosis and they are likely interrelated. The objective of this study is to simultaneously test the relationship between key psychosocial constructs as independent factor scores and recurrent events in CAD patients. There were 1268 CAD outpatients of 97 cardiologists surveyed at two points. Recurrent events or hospitalization in the intervening nine months were reported. Factor analysis of items from the Hospital Anxiety and Depression Scale, Perceived Stress Scale, the ENRICHD Social Support Inventory, and Hostile Attitudes Scale was performed to generate orthogonal factor scores. With adjustment for prognostic variables, logistic regression analysis was performed to examine the relationship between these factor scores and recurrent events. Factor analysis resulted in a six-factor solution: hostility, stress, anxiety, depressive symptoms, support, and resilience. Logistic regression revealed that functional status and anxiety, with a trend for depressive symptoms, were related to experiencing a recurrent event. In this simultaneous test of psychosocial constructs hypothesized to relate to cardiac prognosis, anxiety may be a particularly hazardous psychosocial factor. While replication is warranted, efforts to investigate the potential benefits of screening and to investigate treatments are needed.     

Pigeons' categorization may be exclusively nonanalytic

Recent theoretical and empirical developments in human category learning have differentiated an analytic, rule-based system of category learning from a nonanalytic system that integrates information across stimulus dimensions. In the present study, the researchers applied this theoretical distinction to pigeons' category learning. Pigeons learned to categorize stimuli varying in the tilt and width of their internal striping. The matched category problems had either a unidimensional (rule-based) or multidimensional (information-integration) solution. Whereas humans and nonhuman primates strongly dimensionalize these stimuli and learn rule-based tasks far more quickly than information-integration tasks, pigeons learned the two tasks equally quickly to the same accuracy level. Pigeons may represent a cognitive system in which the commitment to dimensional analysis and category rules was not strongly made. Their performance could suggest the character of the ancestral vertebrate categorization system from which that of primates emerged.     

HIV infection associated post-traumatic stress disorder and post-traumatic growth--a systematic review

The phenomenon of post-traumatic stress has been well documented in the literature as a lasting mental health condition associated with exposure to traumatic life events. The diagnosis and experience of human immunodeficiency virus (HIV) disease may be such a trauma. On the other hand, the phenomenon of post-traumatic growth (PTG) has been described, whereby people show positive mental health growth in the face of such trauma. This systematic review was set out to explore post-traumatic stress disorder (PTSD) and PTG in people with HIV to monitor prevalence, measurement and efficacy of interventions to reduce stress and/or promote growth. Standardised review techniques were used to track reports on both PTSD and PTG. A total of 206 papers were retrieved from the PTSD and HIV searches, and 13 from the PTG and HIV searches. After reviewing the papers for inclusion according to adequacy and relevance criteria and to remove duplicates, 33 PTSD papers and three PTG were available for full coding. Prevalence of PTSD in HIV ranged from 5% to 74%, which were much greater than the 7-10% in the general population. Seven studies showed a relation between trauma and PTSD, while six showed a link between PTSD diagnosis and reduced antiretroviral treatment adherence. Women were more likely to be diagnosed with PTSD. Only three intervention reports were identified that fitted our inclusion criteria. All of these reported on psychological interventions for HIV+?individuals with trauma. The interventions utilised HIV education, training in coping techniques and support groups. Only coping interventions were shown to be effective. PTG was under researched but showed a promising avenue of study. There needs to be harmonised measurement and the evidence base would need strengthening in order to build on the understanding of the impact of PTSD and PTG over the course of HIV disease. There is good evidence to associate HIV diagnosis and experiences during the course of illness as traumatic. PTSD has been shown to be prevalent and there seems to be good evidence to incorporate standardised measures to track the course of the disorder. There is extremely limited evidence that interventions may affect the course of symptom experience. The evidence and insight into PTG show promise but is currently inadequate.     

Behavioral momentum and the law of effect

In the metaphor of behavioral momentum, the rate of a free operant in the presence of a discriminative stimulus is analogous to the velocity of a moving body, and resistance to change measures an aspect of behavior that is analogous to its inertial mass. An extension of the metaphor suggests that preference measures an analog to the gravitational mass of that body. The independent functions relating resistance to change and preference to the conditions of reinforcement may be construed as convergent measures of a single construct, analogous to physical mass, that represents the effects of a history of exposure to the signaled conditions of reinforcement and that unifies the traditionally separate notions of the strength of learning and the value of incentives. Research guided by the momentum metaphor encompasses the effects of reinforcement on response rate, resistance to change, and preference and has implications for clinical interventions, drug addiction, and self-control. In addition, its principles can be seen as a modern, quantitative version of Thorndike's (1911) Law of Effect, providing a new perspective on some of the challenges to his postulation of strengthening by reinforcement.     

Temporal context in concurrent chains: I. Terminal-link duration

Two experiments are reported in which the ratio of the average times spent in the terminal and initial links (Tt/Ti) in concurrent chains was varied. In Experiment 1, pigeons responded in a three-component procedure in which terminal-link variable-interval schedules were in constant ratio, but their average duration increased across components by a factor of two. The log initial-link response ratio was a negatively accelerated function of Tt/Ti. Overall, the data were well described by Grace's (1994) contextual choice model (CCM) with temporal context represented as (Tt/Ti)k or 2Tt/(Tt + Ti), and by Mazur's (2001) hyperbolic value-added model (HVA), with each model accounting for approximately 93% of the variance. In Experiment 2, fixed-parameter predictions for each model were generated, based on the data from Experiment 1, for conditions in which Tt/Ti was varied over a more extreme range. Data were consistent with the predictions of CCM with temporal context represented as 2Tt/(Tt + Ti) and to a lesser extent as (Tt/Ti)k, but not with HVA. Overall, these results suggest that preference increases as a hyperbolic function of Tt/Ti when terminal-link duration is increased relative to initial-link duration, with the terminal-link schedule ratio held constant.     

Development and validation of a Client Problem Profile and Index for drug treatment

The development of the Client Problem Profile and Index are described, and initial concurrent and predictive validity data are presented for a sample of 547 patients in outpatient methadone treatment. Derived from the TCU Brief Intake for drug treatment admissions, the profile covers 14 problem areas related to drug use (particularly cocaine, heroin/opiate, marijuana, other illegal drugs, and multiple drug use), HIV risks, psychosocial-functioning, health, employment, and criminality. Analyses of predictive validity show the profile and its index (number of problem areas) were significantly related to therapeutic engagement, during-treatment performance, and posttreatment follow-up outcomes. Low moderate to high moderate effect sizes were observed in analyses of the index's discrimination.     

DOES SENSITIVITY TO MAGNITUDE DEPEND ON THE TEMPORAL DISTRIBUTION OF REINFORCEMENT?

Our research addressed the question of whether sensitivity to relative reinforcer magnitude in concurrent chains depends on the distribution of reinforcer delays when the terminal-link schedules are equal. In Experiment 1, 12 pigeons responded in a two-component procedure. In both components, the initial links were concurrent variable-interval 40-s variable-interval 40-s, and the terminal links were both 20-s interval schedules in which responses were reinforced by either 4-s of grain in one, or 2-s of grain in the other. The only difference between the components was whether the terminal-link schedules were fixed interval or variable intervals. For all subjects, the relative rate of responding in the initial links for the terminal link that produced the 4-s reinforcer was greater when the terminal links were fixed-interval schedules than when they were variable-interval schedules. This result is contrary to the prediction of Grace's (1994) contextual choice model, but is consistent with both Mazur's (2001) hyperbolic value-added model and Killeen's (1985) incentive theory. In Experiment 2, 4 pigeons responded in a concurrent-chains procedure in which 4-s or 2-s reinforcers were provided independently of responding according to equal fixed-time or mixed-time schedules. Preference for the 4-s reinforcer increased as the variability of the intervals comprising the mixed-time schedules was decreased. Generalized-matching sensitivity of initial-link response allocation to relative reinforcer magnitude was proportional to the geometric mean of the terminal-link delays.     

Suggestibility, social support, and memory for a novel experience in young children

This study examined 5- and 6-year-olds' suggestibility and interviewer demeanor as joint predictors of their memory for a novel experience. Session 1 consisted of children taking part in a novel laboratory event. Session 2 took place after approximately a 1-week delay and consisted of children completing both a memory test concerning what happened during the prior event and the Video Suggestibility Scale for Children (VSSC). During the second session, the interviewer behaved either supportively or nonsupportively. Greater acquiescence on the VSSC was associated with fewer correct responses to misleading questions about the laboratory event in the supportive and nonsupportive conditions and with more errors in response to specific questions in the nonsupportive condition. Results indicate that individual differences in children's suggestibility are related to the accuracy of their memory for separate events, although some of these relations may vary depending on the context in which children are interviewed.     

Individual differences in emotional memory: adult attachment and long-term memory for child sexual abuse

In the present study, attachment-related differences in long-term memory for a highly emotional life event, child sexual abuse (CSA), were investigated. Participants were 102 documented CSA victims whose cases were referred for prosecution approximately 14 years earlier. Consistent with the proposal that avoidant individuals defensively regulate the processing of potentially distressing information (Bowlby, 1980), attachment avoidance was negatively associated with memory for particularly severe CSA incidents. This finding was not mediated by the extent to which participants reported talking about the abuse after it occurred, although post abuse discussion did enhance long-term memory. In addition, accuracy was positively associated with maternal support following the abuse and extent of CSA-related legal involvement. Attachment anxiety was unrelated to memory accuracy, regardless of abuse severity. Implications of the findings for theories of avoidant defensive strategies and emotional memory are discussed.