The effects of voluntary hyperventilation on patients with chest pain without coronary artery disease

The present investigation was designed to examine panic symptom experience in patients with chest pain of nonorganic etiology, using a hyperventilation provocation procedure. Given the recent focus on panic disorder in patients with nonorganic chest pain, we assessed three indices of physiological arousal, subjective anxiety, and endorsement of DSM-III-R panic symptomatology in response to 3 min of voluntary hyperventilation. Subjects included 23 patients with nonorganic chest pain (CP sample) and matched normal controls (NC sample). The results indicate that hyperventilation produced significant increases in skin conductance, heart rate, and upper trapezious EMG in both CP and NC samples. Despite equivalent levels of physiological arousal and subjective anxiety, the CP sample endorsed a greater number of DSM-III-R panic symptoms relative to the NC sample. Examination of post-hyperventilation symptoms indicated that a greater percentage of the CP sample reported palpitations, nausea, and chest pain when compared with normals. Comparison of CP patients with and without Panic Disorder revealed no significant differences on any measure. The results suggests that hyperventilation plays a role in symptom experience in patients with nonorganic chest pain, although anxiety does not appear central in moderating this effect.     

Reduction in rat phosphatidylethanolamine binding protein-1 (PEBP1) after chronic corticosterone treatment may be paralleled by cognitive impairment: a first study

Chronic stress is associated with hippocampal atrophy and cognitive dysfunction. This study investigates how long-lasting administration of corticosterone as a mimic of experimentally induced stress affects psychometric performance and the expression of the phosphatidylethanolamine binding protein (PEBP1) in the adult hippocampus of one-year-old male rats. Psychometric investigations were conducted in rats before and after corticosterone treatment using a holeboard test system. Rats were randomly attributed to 2 groups (n = 7) for daily subcutaneous injection of either 26.8 mg/kg body weight corticosterone or sesame oil (vehicle control). Treatment was continued for 60 days, followed by cognitive retesting in the holeboard system. For protein analysis, the hippocampal proteome was separated by 2D electrophoresis (2DE) followed by image processing, statistical analysis, protein identification via peptide mass fingerprinting and gel matching and subsequent functional network mapping and molecular pathway analysis. Differential expression of PEBP1 was additionally quantified by Western blot analysis. Results show that chronic corticosterone significantly decreased rat hippocampal PEBP1 expression and induced a working and reference memory dysfunction. From this, we derive the preliminary hypothesis that PEBP1 may be a novel molecular mediator influencing cognitive integrity during chronic corticosterone exposure in rat hippocampus.     

Spatial updating in virtual reality: the sufficiency of visual information

Robust and effortless spatial orientation critically relies on "automatic and obligatory spatial updating", a largely automatized and reflex-like process that transforms our mental egocentric representation of the immediate surroundings during ego-motions. A rapid pointing paradigm was used to assess automatic/obligatory spatial updating after visually displayed upright rotations with or without concomitant physical rotations using a motion platform. Visual stimuli displaying a natural, subject-known scene proved sufficient for enabling automatic and obligatory spatial updating, irrespective of concurrent physical motions. This challenges the prevailing notion that visual cues alone are insufficient for enabling such spatial updating of rotations, and that vestibular/proprioceptive cues are both required and sufficient. Displaying optic flow devoid of landmarks during the motion and pointing phase was insufficient for enabling automatic spatial updating, but could not be entirely ignored either. Interestingly, additional physical motion cues hardly improved performance, and were insufficient for affording automatic spatial updating. The results are discussed in the context of the mental transformation hypothesis and the sensorimotor interference hypothesis, which associates difficulties in imagined perspective switches to interference between the sensorimotor and cognitive (to-be-imagined) perspective.     

Investigating the influence of continuous babble on auditory short-term memory performance

A number of factors could explain the adverse effect that babble noise has on memory for spoken words (Murphy, Craik, Li, & Schneider, 2000). Babble could degrade the perceptual representation of words to such an extent that it compromises their subsequent processing, or the presence of speech noise in the period between word presentations could interfere with rehearsal. Thirdly, the top-down processes needed to extract the words from the babble could draw on resources that otherwise would be used for encoding. We tested all these hypotheses by presenting babble either only during word presentation or rehearsal, or by gating the babble on and off 500 ms before and after each word pair. Only the last condition led to a decline in memory. We propose that this decline in memory occurred because participants were focusing their attention on the auditory stream (to enable them to better segregate the words from the noise background) rather than on remembering the words they had heard. To further support our claim we show that a similar memory deficit results when participants perform the same memory task in quiet together with a nonauditory attention-demanding secondary task.     

Children of Prenatally Depressed Mothers: Externalizing and Internalizing Symptoms are Accompanied by Reductions in Specific Social-Emotional Competencies

Studies have shown that child development is negatively affected by prenatal depression. A dysregulated hypothalamic-pituitary-adrenal axis in the pregnant woman, passed to the fetus, is one discussed key mechanism. Studies, investigating primary-school age children, have found effects on antisocial behavior. Effects on internalizing symptoms were not found, but the analysis did not distinguish between anxiety and depression symptoms. Additionally, until now, no objective test data operationalizing social-emotional competencies have been included. The present study examined: 1.Whether the effects on child externalizing symptoms could be replicated; 2. If there are specific effects on child internalizing symptoms, separated for anxiety and depression; and 3. Are child clinical symptoms reflected in reductions in social-emotional competencies. A sample of 61 prenatally depressed and 143 prenatally not-depressed women and their 6–9 year old children were compared, controlling for key confounders in both the perinatal period and in middle childhood. Children of prenatally depressed mothers had more antisocial behavior and depression symptoms reported by their mothers. The prediction of antisocial behavior scores tended to be more significant for boys than for girls. Child anxiety symptoms were primarily explained by current maternal depressive symptoms. Children of prenatally depressed mothers also showed a reduction in social-emotional competencies, specifically regarding the ability to interpret complex social situations. This study showed that, even in a non-clinical sample, there are distinct effects of prenatal depression on child externalizing and internalizing symptoms which are accompanied by reductions in specific social-emotional competencies. These results emphasize that treatment for depressed pregnant women and/or early support for affected families is worthwhile. Additional work is required to identify the underlying biological mechanisms.     

Interactions between view changes and shape changes in picture-picture matching

Four experiments are reported in which pictures of different morphs of novel, complex, 3-D objects, similar to objects which we must identify in the real world, were presented. We investigated how changes of viewpoint influence our ability to discriminate between morphs. View changes had a powerful effect on performance in picture-picture matching tasks when similarly shaped morphs had to be discriminated. Shape changes were detected faster and more accurately when morphs were depicted from the same rather than different views. In contrast, view change had no effect when dissimilarly shaped morphs had to be discriminated. This interaction between the effects of view change and shape change was found both for simultaneous stimulus presentation and for sequential presentation with interstimulus intervals up to 3600 ms. The interaction was found after repeated presentations of the stimuli before the matching task and after practice at the matching task as well as after no such pre-exposure to the stimuli or to the task. The results demonstrate the difficulty in activating abstract, view-insensitive representations to help to achieve object constancy, even when matching over long interstimulus intervals or after stimuli have already been seen many times.     

Some Useful 16-Valued Logics: How a Computer Network Should Think

In Belnaps useful 4-valued logic, the set 2={T,F} of classical truth values is generalized to the set 4=(2)={,{T},{F},{T,F}}. In the present paper, we argue in favor of extending this process to the set 16=(4) (and beyond). It turns out that this generalization is well-motivated and leads from the bilattice FOUR₂ with an information and a truth-and-falsity ordering to another algebraic structure, namely the trilattice SIXTEEN₃ with an information ordering together with a truth ordering and a (distinct) falsity ordering. Interestingly, the logics generated separately by the algebraic operations under the truth order and under the falsity order in SIXTEEN₃ coincide with the logic of FOUR₂, namely first degree entailment. This observation may be taken as a further indication of the significance of first degree entailment. In the present setting, however, it becomes rather natural to consider also logical systems in the language obtained by combining the vocabulary of the logic of the truth order and the falsity order. We semantically define the logics of the two orderings in the extended language and in both cases axiomatize a certain fragment comprising three unary operations: a negation, an involution, and their combination. We also suggest two other definitions of logics in the full language, including a bi-consequence system. In other words, in addition to presenting first degree entailment as a useful 16-valued logic, we define further useful 16-valued logics for reasoning about truth and (non-)falsity. We expect these logics to be an interesting and useful instrument in information processing, especially when we deal with a net of hierarchically interconnected computers. We also briefly discuss Arielis and Avrons notion of a logical bilattice and state a number of open problems for future research.Dedicated to Nuel D. Belnap on the occasion of his 75th Birthday