Contrasting the ironic monitoring and motivational explanations of postsuppressional rebound

Suppressing a thought often results in postsuppressional rebound, that is, a subsequent increase in the incidence of the suppressed thought. The present study was dcsigned to distinguish between two explanations of rebound: Wegner's 1994 ironic monitoring theory and Liberman and Forster's 2000 motivational account. Participants (99 Deakin University students) first suppressed, then expressed, thoughts of a white bear. In some conditions, a delay--presented as occurring either intentionally or unintentionally--between suppression and expression was introduced. In other conditions, participants concurrently completed a memory task and were encouraged to antribute the difficulty of suppression either to this task or to the requirement of suppression. An intentional delay, but not an unintentional delay, reduced rebound, while attributing difficulty to the suppression requirement was associated with greater rebound than was attributing it to the memory task. The results are interpreted as supporting Liberman and Forster's motivational account of rebound.     

Acetylcholine release in hippocampus and striatum during testing on a rewarded spontaneous alternation task

The present experiment tested male Sprague-Dawley rats for spontaneous alternation performance in a food-rewarded Y-shaped maze. Microdialysis samples, later assessed for acetylcholine concentration, were collected from the hippocampus and striatum of each rat prior to and during testing; testing sessions lasted 20 min. Early in testing, rats alternated at a rate of 72%. Alternation scores increased throughout the 20-min testing session and reached 93% during the last 5 min. The behavioral findings suggest that, during testing, rats changed the basis for their performance from a spatial working memory strategy to a persistent turning strategy. ACh release in both hippocampus and striatum increased at the onset of testing. Increases in ACh release in the striatum began at 18% above baseline during the first 5 min of testing and steadily increased reaching 58% above baseline during the final 5 min. The progressive rise of striatum ACh release during testing occurred at about the time rats adopted a persistent turning strategy. In contrast, ACh release in the hippocampus increased by 50% with the onset of testing and remained at this level until declining slightly during the last 5 min of testing. The relative changes in ACh release in the striatum and hippocampus resulted in a close negative relationship between the ratio of ACh release in the hippocampus/striatum and alternation scores.     

Working memory consolidation is abnormally slow in schizophrenia

This study reports evidence that patients with schizophrenia demonstrate a slowing of working memory (WM) consolidation, which is the process of transforming transient perceptual representations into durable WM representations. Sixteen schizophrenia patients and 16 healthy control participants performed a task measuring the visual WM consolidation rate in a change-detection paradigm. A target display containing 3 colored squares was followed by a variable delay of 17-483 ms, a pattern mask, and then a test stimulus. This pattern mask does not interfere with perception but disrupts WM consolidation. Control participants reached no-mask performance by 250 ms, indicating completed WM consolidation, whereas patients failed to reach no-mask performance by 483 ms. Slowed consolidation may play an important and largely unrecognized role in schizophrenia.     

In search of "master mindreaders": are psychics superior in reading the language of the eyes?

Much of the effort to understand the brain substrate of theory of mind and empathy has involved the study of individuals with deficits in that domain, such as those on the autism spectrum. Studying individuals with presumed superior abilities in picking up social signals may yield important additional information. We predicted that psychic readers may have superior abilities and tested this by contrasting a group of 22 professional psychic readers with matched controls on a measure of theory of mind ("Reading the Mind in the Eyes" test) and a multidimensional measure of empathy [Interpersonal Reactivity Index (IRI)]. Although psychic readers were not superior in reading the language of the eyes, they were shown to have more cognitive empathy, as measured with the "Fantasy" subscale of the IRI. We discuss the merits of research involving "experts" in social cognition and propose other possible groups of "master mindreaders."     

Spatial location in color vision

Ross argues that the location problem for color-the problem of how it is represented as occupying a particular location in space-constitutes an objection to color subjectivism. There are two ways in which the location problem can be interpreted. First, it can be read as a why-question about the relation of visual experience to the environment represented: Why does visual experience represent a patch of color as located in this part of space rather than that? On this interpretation, the subjectivist can answer Ross's objection by appealing to the physical location of reflectance rather than color. Second, it can be read as a how-question about visual representation itself: How does visual experience put together the experience of a color with the experience of its being located in space? This version makes the location problem a problem about visual experience itself and renders the ontology of color irrelevant to its solution. The location problem is thus no more a problem for the color subjectivist than for the color realist.     

A Relational Psychodynamic Perspective on Assimilative Integration

In this paper we discuss recent advances in relational psychoanalytic thinking, and demonstrate how an assimilative approach to integration can be based on this theoretical and clinical model. We describe 3 instances in which active interventions may be used to enhance relationally oriented, psychoanalytic work: by impacting on relationships outside of therapy that maintain pathological patterns, by filling in intrapsychic deficits, and by supporting the patient's active efforts at change. We provide clinical examples to illustrate each of these points.     

Fluctuations in brain glucose concentration during behavioral testing: dissociations between brain areas and between brain and blood

Traditional beliefs about two aspects of glucose regulation in the brain have been challenged by recent findings. First, the absolute level of glucose in the brain's extracellular fluid appears to be lower than previously thought. Second, the level of glucose in brain extracellular fluid is less stable than previously believed. In vivo brain microdialysis was used, according to the method of zero net flux, to determine the basal concentration of glucose in the extracellular fluid of the striatum in awake, freely moving rats for comparison with recent hippocampal measurements. In addition, extracellular glucose levels in both the hippocampus and the striatum were measured before, during, and after behavioral testing in a hippocampus-dependent spontaneous alternation task. In the striatum, the resting extracellular glucose level was 0.71 mM, approximately 70% of the concentration measured previously in the hippocampus. Consistent with past findings, the hippocampal extracellular glucose level decreased by up to 30 +/- 4% during testing; no decrease, and in fact a small increase (9 +/- 3%), was seen in the striatum. Blood glucose measurements obtained during the same testing procedure and following administration of systemic glucose at a dose known to enhance memory in this task revealed a dissociation in glucose level fluctuations between the blood and both striatal and hippocampal extracellular fluid. These findings suggest, first, that glucose is compartmentalized within the brain and, second, that one mechanism by which administration of glucose enhances memory performance is via provision of increased glucose supply from the blood specifically to those brain areas involved in mediating that performance.     

Patterns of brain acetylcholine release predict individual differences in preferred learning strategies in rats

Acetylcholine release was measured simultaneously in the hippocampus and dorsal striatum of rats before and during training on a maze that could be learned using either a hippocampus-dependent spatial strategy or a dorsal striatum-dependent turning strategy. A probe trial administered after rats reached a criterion of 9/10 correct responses revealed that about half of the rats used a spatial strategy and half a turning strategy to solve the task. Acetylcholine release in the hippocampus, as well as the ratio of acetylcholine release in the hippocampus vs. the dorsal striatum, measured either before or during training, predicted these individual differences in strategy selection during learning. These findings suggest that differences in release of acetylcholine across brain areas may provide a neurobiological marker of individual differences in selection of the strategies rats use to solve a learning task.     

Worry and emotionality components of test anxiety

The purpose of the present study was to investigate the relationship between trait measures of Worry and Emotionality and test anxiety related variables. Ninety-eight undergraduate students completed the Test Anxiety Inventory (TAI) and the following self-report measures toward the end of the psychology exam: Checklist of Positive and Negative Thought, Checklist of Body Sensations (CBS), and Subjective Units of Discomfort Scale (SUDS). Further, the students' scores on the psychology exam and the students' grade point averages (GPA) served as outcome measures of test anxiety. In general the results supported the discriminant validity of the Worry and Emotionality subscales of the TAI. Worry was found to be correlated with measures of internal dialogue and Emotionality was found to be correlated with the self-reported arousal measures.     

Personality test reliability: correlates for older subjects

This study reports the findings of an investigation of psychological and social factors related to test-retest stability and change in scores on the Eysenck Personality Inventory given to 167 older men and women. Higher reliability coefficients on the Eysenck were associated with better scores on a measure of well being and higher levels of education.