Physiological arousal and attention in veterans with posttraumatic stress disorder

Psychophysiological reactivity has been well documented in WWII, Korean Conflict, and Vietnam veterans with posttraumatic stress disorder (PTSD). In addition, these individuals have demonstrated cognitive impairments within the domains of attention, concentration, new learning, and memory. However, there has been no research examining the impact of physiological arousal on attention in individuals with PTSD. This study documents the level of physiological arousal and associated disruption of attentional abilities in 28 Persian Gulf War veterans (18 without PTSD or other psychopathology and 10 with PTSD). This population represents a group of combat trauma victims who experienced a relatively acute onset of PTSD, thus providing a unique opportunity to compare prior psychophysiological and cognitive results with a group of veterans who manifested a recent onset of PTSD. Results indicated relatively comparable psychophysiological reactivity and arousal between Persian Gulf War veterans with PTSD and Persian Gulf War veterans without PTSD. Furthermore, attentional processes of veterans with PTSD were not more disrupted than in comparison soldiers. Results suggest that the intensity and chronicity of the disorder may impact physiological arousal and disruption of cognitive functioning. Following Persian Gulf War veterans with PTSD over time may reveal that psychophysiological arousal becomes more pronounced with chronicity, perhaps as memory networks become strengthened and/or neuroendocrine systems become increasingly disrupted.     

Why-questions, determinism and circular reasoning

In this article I shall aim at showing that there exists beneath the surface of many why-questions about human behaviour a nest of deterministic assumptions which can preclude their ever being truly answered. A symptom of the presence of these underlying assumptions can be observed in an explanation-seeking dialogue in which the questioner persistently tries to discover why a certain human behaviour occurred. He repeats his why-question until he gets the type of answer he wants, but in the process he effectively reasons in a circle. If the repeated questioning with its implied circular reasoning becomes chronic, then the questioner will beg the question with regards to the answer he desires and consequently run the risk of missing the truth.     

Medical problems,maladaptive behaviors,and the developmentally disabled

Research has shown that aberrant behaviors of people with developmental disabilities have multiple determinants; of these, medical problems and their potential relations to aberrant behaviors, have been, for the most part, not studied. This retrospective study examined the relations of 26 acute medical treatements to the aberrant behaviors of 10 elderly people with developmental disabilities. Results showed that 73.1% of the aberrant behaviors decreased in frequency after medical treatments. The study suggests the importance of acute medical problems and treatments as possible factors in the occurrence of aberrant behaviors in this population.     

Maintained nodal-distance effects in equivalence classes

Twelve subjects were trained to select one of two stimuli from a pair (the B pair) when presented with one of two stimuli from another pair (the A pair), thus establishing two AB relations, A1-B1 and A2-B2. In a similar fashion, additional stimuli were used to establish BC, CD, and DE relations. Trials used to train all relations occurred in each session. Once performances were established, probe trials were introduced that tested for the emergence of untrained relations (e.g., B1-D1 or A1-E1). These emergent relations were categorized according to nodal distance (i.e., the number of stimuli across which transitivity would have to hold in order for the relation to emerge). For example, a test for A2-C2 crosses one node (B2), whereas a test for A1-E1 crosses three nodes (B1, C1, and D1). Only 2 of the subjects formed equivalence classes. The evocation of class-appropriate responding by each emergent-relation probe was an inverse function of nodal distance for all 12 subjects. In addition, performance on the originally trained relations was disrupted by the introduction of probes. The 2 subjects who exhibited equivalence classes were then trained to make different numbers of key presses in the presence of each of the four A and E stimuli. In a response-transfer test, the B, C, and D stimuli evoked the responses trained to the A and E stimuli in the same equivalence class. Likelihood of class-appropriate responses was an inverse function of nodal distance, and this pattern persisted across testing. Reaction times in the transfer test were an inverted U-shaped function of nodal distance. Because training of the baseline relations occurred concurrently and the B, C, and D stimuli were presented an equal number of times before the transfer test, the test performances illustrate effects of nodal distance that were not confounded by order or amount of experience with the stimuli. The results imply that ordered, sequential exposure to individual stimulus relations may facilitate the development of equivalence classes and that the relatedness of stimuli within an equivalence class is a relatively permanent inverse function of nodal distance.     

Rasch models for item bundles

This paper discusses the application of a class of Rasch models to situations where test items are grouped into subsets and the common attributes of items within these subsets brings into question the usual assumption of conditional independence. The models are all expressed as particular cases of the random coefficients multinomial logit model developed by Adams and Wilson. This formulation allows a very flexible approach to the specification of alternative models, and makes model testing particularly straightforward. The use of the models is illustrated using item bundles constructed in the framework of the SOLO taxonomy of Biggs and Collis.The work of both authors was supported by fellowships from the National Academy of Education Spencer Fellowship.     

Punished and unpunished responding in multiple variable-interval schedules

The performance of rats trained on multiple variable-interval schedules was examined before, during, and after punishment. The same linear function related relative response rates to relative density of reinforcement both in the presence and absence of punishment. Equal relative suppression was seen in both the high and low reinforcement density components. The intercept value of the function was zero. Each component of the schedule was programmed on a separate lever: thus during any component, there was an opportunity for responses on the nonoperative lever (errors). The proportions of these errors declined to a near-zero value during punishment and did not regain their prepunishment values after punishment was removed, suggesting that some discrimination learning occurred during punishment. Recovery of response rate during punishment was seen only where a greater-than-zero probability of reinforcement was associated with the response.     

A forty-three day avoidance session

A single Sprague-Dawley rat was subjected to an extended discriminated avoidance session in effect continuously for over 1000 hr (43 days). The longest possible shock-free interval that the subject could obtain without responding was 5 min. Since the subject did not sleep through shock, all resting or sleeping was interrupted at least once every 5 min by either a response or a shock. Neither the experimental (avoidance) animal nor a second animal which received all shocks not avoided by the first, gave any appearance of ill effects from the protracted session.     

Specific fears as predictors of generalized anxiety

Three hundred thirty-seven female undergraduates completed the Trait Form of the State-Trait Anxiety Inventory (STAI) and the Fear Survey Schedule-II (FSS) to determine if any specific fear factor was significantly related to STAI score. All fear factor scores and the total FSS-II score were significantly correlated with the STAI score and with each other. A stepwise regression procedure indicated that Factor 1, Fear of Social Interaction, accounted for 25.2% of the variance in STAI scores (p <.001), while Factor 4, of Negative Social Evaluation, accounted for an additional 1.8% of the variance (p <.01). The implications for theory, assessment, and intervention are discussed.