Assessment of DSM-IV personality disorders in obsessive-compulsive disorder: comparison of clinical diagnosis, self-report questionnaire, and semi-structured interview

In patients with obsessive-compulsive disorder, personality disorders are not many times assessed according to DSM-IV criteria. The purpose of the present study is to examine the prevalence of personality disorders diagnosed according to the DSM-IV in a severely disordered OCD population (n=65) with three different methods of assessing personality disorders (structured interview, questionnaire, and clinical diagnoses). Furthermore, correspondence between these different methods was investigated and their construct validity was examined by relating the three methods to external variables. Each method resulted in a predominance of Cluster C personality disorders, and obsessive-compulsive personality disorder had the highest prevalence. However, there was generally low correspondence regarding which patient had which personality disorder. Results concerning the relation of external variables were the most promising for the structured clinical interview.     

WAIS-III factor index score patterns after traumatic brain injury

Profile subtypes, based on the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) factor index scores, were examined in a sample of 166 patients with traumatic brain injury (TBI) by means of a two-stage clustering procedure. Three reliable subtypes were found that were differentiated primarily by level of performance across all factor index scores, although each of them demonstrated a relative weakness on the Processing Speed index. These subtypes were then validated on the basis of demographic variables, injury parameters, and additional psychometric measures that had not been included in the clustering procedures. The results indicated that performance on the WAIS-III after TBI was affected by both injury severity and level of education. It is concluded that there is no unique "signature" profile on the WAIS-III after TBI, except that a relative strength on the Processing Speed index is uncommon with this condition.     

Electrophysiological correlates of anterior cingulate function in a go/no-go task: Effects of response conflict and trial type frequency

Neuroimaging and computational modeling studies have led to the suggestion that response conflict monitoring by the anterior cingulate cortex plays a key role in cognitive control. For example, response conflict is high when a response must be withheld (no-go) in contexts in which there is a prepotent tendency to make an overt (go) response. An event-related brain potential (ERP) component, the N2, is more pronounced on no-go than on go trials and was previously thought to reflect the need to inhibit the go response. However, the N2 may instead reflect the high degree of response conflict on no-go trials. If so, an N2 should also be apparent when subjects make a go response in conditions in which nogo events are more common. To test this hypothesis, we collected high-density ERP data from subjects performing a go/no-go task, in which the relative frequency of go versus no-go stimuli was varied. Consistent with our hypothesis, an N2 was apparent on both go and no-go trials and showed the properties expected of an ERP measure of conflict detection on correct trials: (1) It was enhanced for low-frequency stimuli, irrespective of whether these stimuli were associated with generating or suppressing a response, and (2) it was localized to the anterior cingulate cortex. This suggests that previous conceptions of the no-go N2 as indexing response inhibition may be in need of revision. Instead, the results are consistent with the view that the N2 in go/no-go tasks reflects conflict arising from competition between the execution and the inhibition of a single response.     

State-dependent and odor-mediated anemotactic responses of a micro-arthropod on a novel type of locomotion compensator

A novel type of locomotion compensator was designed and tested for its use in orientation behavior experiments with a predatory mite. In this apparatus, displacements of the test animal in the two-dimensional plane are recorded using video equipment and a servosphere that keeps the animal in focus. Thex andy displacements are registeredusing two rotation encoders and are compensated using a pair of servo-motors, in such a way that the animal is always positioned on top of the sphere, yet moves freely. Well-fed and starved predators were tested for their responses to (1) still air, (2) a stimulus-free air flow, (3) an air flow with odors from uninfested Lima bean leaves, and (4) an air flow with odors from Lima bean leaves infested by plant-feeding mites, the prey of the predatory mites. Anemotactic responses of adultPhytoseivlus persimilis females were feeding state dependent. Well-fed predators moved downwind under Treatments 1–3 but moved neither up-nor downwind in the presence of odors from infested plants (Treatment 4). Starved predators moved upwind under all treatments. These results are in agreement with those of earlier studies in a wind tunnel, and therefore, the new type of locomotion compensator (LC-100) offers an excellent method for studying the orientation behavior of micro-arthropods.     

Large-scale ensemble averaging of ambulatory impedance cardiograms

Impedance cardiography has been used increasingly to measure human physiological responses to emotional and mentally engaging stimuli. The validity of large-scale ensemble averaging of ambulatory impedance cardiograms was evaluated for preejection period (PEP), interbeat interval, and dZ/dt_(min) amplitude. We tested whether the average of “classical” 60-sec ensemble averages across periods with fixed activity, posture, physical load, social situation, and location could be accurately estimated from a single large-scale ensemble average spanning these entire periods. Impedance and electrocardiograms were recorded for about 24-h from 21 subjects. Recordings were scored by seven raters, using both methods for each subject. Good agreement (average intraclass correlation coefficient was .91) between both ensemble averaging methods was found for all three cardiac function measures. The results indicate that for unambiguous ambulatory impedance cardiograms, large-scale ensemble averaging is valid, which makes measuring prolonged changes in cardiac sympathetic activity by measuring ambulatory PEP feasible even in large epidemiological samples.     

Neuroticism and social comparison orientation as moderators of affective responses to social comparison at work

In a study among 72 nurses, the affective consequences of social comparison were examined and related to neuroticism (N) and to social comparison orientation (SCO). Participants were confronted with a bogus interview with an upward versus a downward comparison target. Positive affect and identification were higher, and negative affect was lower, in the upward than in the downward comparison condition. Independent of their SCO, the higher individuals were in N, the less they identified with the upward comparison target, the more they identified with the downward comparison target, and the less positive affect they showed following confrontation with the upward comparison target. In contrast, independent of their level of N, the higher individuals were in SCO, the more negative affect they showed following confrontation with the downward comparison target. The effects on negative affect stayed the same when controlling for positive affect, and the effects on positive affect stayed the same when controlling for negative affect. These effects were also obtained when perceived direction was used as a predictor instead of the experimentally manipulated direction. It is concluded that, although N and SCO are correlated, these variables seem to have independent and distinct effects upon the responses to social comparison information.     

Changes in limb stiffness under conditions of mental stress

In 2 experiments, the effects of mental stress on limb stiffness were investigated. The relative contribution to arm stiffness of individual muscle activity, co-contraction, muscle reflexes, and postural adjustments were examined. In each experiment, participants (N = 24, Experiment 1; N = 16, Experiment 2) held their supinated hand under a tray that they were required to return to horizontal after it had been suddenly released. Electromyographic activity in the biceps and triceps muscles was recorded, as were elbow and wrist angles and tray displacement. In Experiment 1, mental arithmetic stress was shown to lead to decreased tray displacement (i.e., increased resistance) compared with displacements under the control, unstressed condition, as well as to increased elbow flexion before tray release. In Experiment 2, the increased resistance to perturbation caused by mental stress was found to be independent of initial elbow angle, but to vary as a function of the amount of upward force exerted before tray release. The authors conclude that stress-induced increases in limb stiffness result from changes in the initial position of the elbow, specified by its angle, together with the initial force exerted by participants to counteract the mechanical perturbations.     

Quality of life before and after lung transplantation in patients with emphysema versus other indications

Whether lung transplantation improves Health-related Quality of Life in patients with emphysema and other end-stage lung diseases before and after lung transplantation was examined. Between 1992 and 1999, 23 patients with emphysema and 19 patients with other indications completed self-administered questionnaires before lung transplantation, and at 4, 7, 13, and 25 mo. after transplantation. The questionnaire included the Nottingham Health Profile, the State-Trait Anxiety Inventory, the Self-rating Depression Scale, the Index of Well-being, the self-report Karnofsky Index, and four respiratory-specific questions. Neither before nor after transplantation were significant differences found on most dimensions of Health-related Quality of Life between patients with emphysema and other indications. Before transplantation, both groups report major restrictions on the dimensions Energy and Mobility of the Nottingham Health Profile, low experienced well-being, depressive symptoms, and high dyspnea. About 4 mo. after transplantation, most Health-related Quality of Life measures improved significantly in both groups. These improvements were maintained in the following 21 mo.