Beyond statistical inference: A decision theory for science

Traditional null hypothesis significance testing does not yield the probability of the null or its alternative and, therefore, cannot logically ground scientific decisions. The decision theory proposed here calculates the expected utility of an effect on the basis of (1) the probability of replicating it and (2) a utility function on its size. It takes significance tests—which place all value on the replicability of an effect and none on its magnitude—as a special case, one in which the cost of a false positive is revealed to be an order of magnitude greater than the value of a true positive. More realistic utility functions credit both replicability and effect size, integrating them for a single index of merit. The analysis incorporates opportunity cost and is consistent with alternate measures of effect size, such as r2 and information transmission, and with Bayesian model selection criteria. An alternate formulation is functionally equivalent to the formal theory, transparent, and easy to compute.     

Sleep deprivation impairs object recognition in mice

Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in an object recognition task in OF1 mice subjected to 6h SD either immediately after the acquisition phase (0-6 SD) or 6h later (7-12 SD), and in corresponding undisturbed controls. Motor activity was continuously recorded with infrared sensors. All groups explored two familiar, previously encountered objects to a similar extent, both at the end of the acquisition phase and 24h later during the test phase, indicating intact familiarity detection. During the test phase 0-6 SD mice failed to discriminate between the single novel and the two familiar objects. In contrast, the 7-12 SD group and the two control groups explored the novel object significantly longer than the two familiar objects. Plasma corticosterone levels determined after SD did not differ from time-matched undisturbed controls, but were significantly below the level measured after learning alone. ACTH did not differ between the groups. Therefore, it is unlikely that stress contributed to the memory impairment. We conclude that the loss of sleep and the activities the mice engaged in during the SD, impaired recognition memory retrieval, when they occurred immediately after acquisition. The delayed SD enabled memory consolidation during the 6h when the mice were allowed to sleep, and had no detrimental effect on memory. Neither SD schedule impaired object familiarity processing, suggesting that only specific cognitive abilities were sensitive to the intervention. Sleep may either actively promote memory formation, or alternatively, sleep may provide optimal conditions of non-interference for consolidation.     

Inflammation in white matter: clinical and pathophysiological aspects

While the central nervous system (CNS) is generally thought of as an immunopriviledged site, immune-mediated CNS white matter damage can occur in both the perinatal period and in adults, and can result in severe and persistent neurological deficits. Periventricular leukomalacia (PVL) is an inflammatory white matter disease of premature infants that frequently results in cerebral palsy (CP). Clinical and experimental studies show that both hypoxic/ischemic and innate immune mechanisms contribute to the destruction of immature oligodendroglia and of axons in the deep cerebral white matter in PVL. No data are yet available as to whether there is any genetic predisposition to PVL or to its neurological sequelae. Multiple sclerosis (MS) is an inflammatory white matter disease that often begins in young adulthood, causes multifocal destruction of mature oligodendroglia and of axons, and eventually leads to substantial cumulative neurological disability. Certain genetic polymorphisms contribute to susceptibility to MS, and adaptive immune responses to myelin-associated self antigens, or to exogenous antigens that mimic these self antigens, play a central role in the pathophysiology of this disease.     

Positive vs. negative switching barriers: the influence of service consumers' need for variety

• In this study, we deal with the existing debate related to the establishment of switching barriers retaining customers in the relationship with a provider. In particular, we demonstrate that ‘positive’ switching barriers (relational benefits) play a greater role that the ‘negative’ ones (switching costs and availability and attractiveness of other providers' offers) in determining customer satisfaction and retention. On the other hand, we include customers' need for variety in the proposed model, in order to demonstrate that a higher level of this psychological trait will lead to a lower perception of the existence of switching barriers. The hypotheses proposed have been tested for a services context on a sample of 800 individuals, using the technique ‘Partial Least Squares’ (PLS). Our findings lead to some interesting managerial implications.

Copyright © 2006 John Wiley & Sons, Ltd.     

The role of awareness in delay and trace fear conditioning in humans

Expression of conditional fear without awareness has been previously demonstrated during delay conditioning, a procedure in which the conditioned stimulus (CS) and unconditioned stimulus (UCS) overlap. However, less is known about the role of awareness in trace fear conditioning, where an interval of time separates the CS and UCS. The present study assessed skin conductance response (SCR) and UCS expectancy during delay and trace conditioning. UCS predictability was varied on a trial-bytrial basis by presenting perithreshold auditory CSs. Differential UCS expectancies were demonstrated only on perceived delay and trace trials. Learning-related SCRs were observed during both perceived and unperceived delay CSs. In contrast, differential SCRs were demonstrated only for perceived trace CSs. These data suggest that awareness is necessary for conditional responding during trace, but not delay, fear conditioning.     

Psychological management and body image issues in facial transplantation

Facial transplantation, although controversial, is proposed as a major advance in facial reconstructive surgery, with the first partial transplant having taken place in France in November 2005. Although the psychological impact of facial transplantation will not be understood until several procedures have been carried out, this article examines the psychological issues likely to arise with particular reference to body image. A detailed framework for anticipation and management of psychological change is proposed. Pre-operative preparation must include thorough psychological preparation for the patient and their family. The immediate post-operative period is likely to be challenging, and a detailed management plan is proposed emphasising early return to function; subsequent psychological issues including altered body image, anxiety, shame, depression, communication and behavioural avoidance are discussed and a management strategy based on cognitive behavioural principles is proposed for the first post-operative year. Previous discussion frames psychological outcome in terms of complication and risk, tending to downplay the potential advantages of a successful procedure; the focus of this paper is on ensuring psychological adjustment as an inevitable consequence of change.     

DSM-defined anxiety disorders symptoms in South African youths: Their assessment and relationship with perceived parental rearing behaviors

This study investigated DSM-defined anxiety symptoms in South African youths. Children and adolescents (N = 701) from various cultural groups completed the SCARED and a questionnaire measuring perceived parental rearing behaviors. Results indicated that the psychometric properties of the SCARED were satisfactory in the total sample of South African youths, and acceptable in colored and black children and adolescents. Further, colored and black youths displayed higher SCARED scores than white youths, and there were also differences in the perceived parental rearing behaviors of the cultural groups. White youths generally rated their parents' rearing behaviors as less anxious, overprotective, and rejective, but more emotionally warm than colored and black youths. Finally, positive correlations were found between anxious rearing, overprotection, and rejection and anxiety symptoms. The clinical and research implications of these findings are briefly discussed.     

Effectiveness of dialectical behaviour therapy for borderline personality disorder in an inpatient setting

This study evaluates the effectiveness of dialectical behaviour therapy (DBT) for borderline personality disorder (BPD) in an unselected, comorbid population seeking 3-month inpatient treatment. We studied 50 consecutively admitted individuals (44 women, six men) with BPD as defined by DSM-IV at three time points (at admission, at discharge, and at the 15-month follow-up). For the clinical diagnoses, we used the Structured Clinical Interview for DSM-IV (SCID) and compared the frequencies of comorbid axis I and axis II disorders at admission and at the 15-month follow-up. Overall, participants showed a high degree of comorbidity. Psychopathology was significantly reduced at post-treatment and at follow-up. Effect sizes for outcome measures were within the range of those of previous studies. Our findings support the notion that the results of the DBT efficacy research can be generalized to an inpatient setting and to patients with BPD disorder with high comorbidity.     

The influence of prior knowledge and repeated questioning on children's long-term retention of the details of a pediatric examination

Children's recall of the details of pediatric examinations was examined over the course of a 6-month interval. Although the 83 4- to 7-year-old participants reported a substantial amount of information at each assessment, performance declined over time, dropping sharply over the course of 3 months but then remaining constant out to the final interview at 6 months. As expected, older children provided more total information than younger children did and reported a greater proportion of the event components in response to general rather than specific questions. However, comparable patterns of remembering and forgetting over time were observed at each age level. In addition, no effects of repeated questioning--in the form of an interview at 3 months for half of the children--were observed on performance at the 6-month assessment. Moreover, children's prior knowledge about routine doctor visits was assessed before the checkup for half of the participants at each age and was associated with initial but not delayed recall. Although knowledge increased with age as expected, it nonetheless affected recall over and above the influence of age.