Pavlovian theory of dreaming

Pavlovian theory provides a conceptual scheme for the examination of recent empirical data on dreaming. Consistencies are examined between these data and Pavlovian theory of the general properties of the nervous system. An equation is made between Pavlov’s excitation-inhibition continuum, the REM-NREM cycle, and the basic rest-activity cycle. Speculations, based on this equation, are made about the inter-relation between waking and sleeping behaviors. Testable hypotheses are suggested throughout the paper.     

Preference,resistance to change,and the cumulative decision model

According to behavioral momentum theory (Nevin & Grace, 2000a), preference in concurrent chains and resistance to change in multiple schedules are independent measures of a common construct representing reinforcement history. Here I review the original studies on preference and resistance to change in which reinforcement variables were manipulated parametrically, conducted by Nevin, Grace and colleagues between 1997 and 2002, as well as more recent research. The cumulative decision model proposed by Grace and colleagues for concurrent chains is shown to provide a good account of both preference and resistance to change, and is able to predict the increased sensitivity to reinforcer rate and magnitude observed with constant‐duration components. Residuals from fits of the cumulative decision model to preference and resistance to change data were positively correlated, supporting the prediction of behavioral momentum theory. Although some questions remain, the learning process assumed by the cumulative decision model, in which outcomes are compared against a criterion that represents the average outcome value in the current context, may provide a plausible model for the acquisition of differential resistance to change.     

Rat choice in rapidly changing concurrent schedules

In two experiments, experimentally naïve rats were trained in concurrent variable‐interval schedules in which the reinforcer ratios changed daily according to a pseudorandom binary sequence. In Experiment 1, relative response rates showed clear sensitivity to current‐session reinforcer ratios, but not to previous sessions' reinforcer ratios. Within sessions, sensitivity to the current session's reinforcement rates increased steadily, and by session end, response ratios approached matching to the current‐session reinforcer ratios. Across sessions, sensitivity to the current session's reinforcer ratio decreased with continued exposure to the pseudorandom binary sequence, contrary to expectations based on previous studies demonstrating learning sets. Using a second group of naïve rats, Experiment 2 replicated the main results from Experiment 1 and showed that although there were increases over sessions in both changeover rate and response rate during the changeover delay, neither could explain the accompanying reductions in sensitivity. We consider the role of reinforcement history, showing that our results can be simulated using two separate representations, one local and one nonlocal, but a more complex approach will be needed to bring together these results and other history effects such as learning sets and spontaneous recovery.     

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.     

Perspectivism as a Way of Knowing in the Zhuangzi

A perspectivist theory is usually taken to mean that (1) our knowledge of the world is inevitably shaped by our particular perspectives, (2) any one of these perspectives is as good as any other, and (3) any claims to objective or authoritative knowledge are consequently without ground. Recent scholarship on Nietzsche, however, has challenged the prevalent view that the philosopher holds (2) and (3), arguing instead that his perspectivism aims at attaining a greater level of objectivity. In this essay, I attempt a structurally similar reinterpretation of Zhuangzi’s perspectivism. I argue that while the Chinese thinker sees all knowledge as perspective-dependent, he thinks that some perspectives are broader and more accurate than others. He utilizes shifts in perspective precisely in order to attain these superior perspectives, which constitute what he calls da zhi 大知, or “greater knowledge.” Whereas Nietzsche sees his perspectivism as methodologically continuous with the sciences, Zhuangzi’s “greater knowledge” has the goal of ensuring our survival and well-being in the everyday world.