Group versus individual cognitive-behavioural treatment for obsessive-compulsive disorder: a controlled trial

The efficacy of group cognitive behaviour therapy (CBT) for obsessive-compulsive disorder (OCD) has received relatively little research attention compared with the large number of studies that have investigated individual CBT. The current study is the first controlled study to compare an identical CBT protocol, containing both cognitive and behavioural elements, delivered either individually or in a group. Participants were randomly assigned to either 10 weeks of individual CBT, 10 weeks of group CBT or a 10 week wait-list. Participants with significant rates of secondary comorbidity were included in the study to enhance the generalisability of results. Intention-to-treat and completer analyses were carried out and indicated no differences between the group and individual treatments on outcome measures. Large effect sizes were found for both conditions. Analysis of clinically significant change indicated that the individual treatment was associated with a more rapid response but that both treatments had equivalent rates of recovered participants by brief follow-up. The importance of further investigations of the efficacy of group CBT for OCD is discussed.     

Cross-modal attention capture by affective stimuli: Evidence from event-related potentials

The P3 component of the event-related potential (ERP) to an acoustic startle probe is modulated during picture viewing, with reduced P3 amplitude when participants view either pleasant or unpleasant, as opposed to neutral, pictures. We have interpreted this as reflecting capture of attentional resources by affective pictures, with fewer resources available for processing the secondary startle probe. In the present study, we tested this resource allocation hypothesis by presenting either pictures or sounds as foreground stimuli, with the prediction that P3 amplitude in response to secondary startle probes would be reduced for affectively engaging foregrounds regardless of modality. Using dense-array electroencephalography and a source estimation procedure, we observed that P3 amplitude was indeed smaller when startle probes were presented during emotional, as opposed to neutral, stimuli for both sound and picture foregrounds. Source modeling indicated a common frontocentral maximum of P3 modulation by affect. The data support the notion that emotionally arousing stimuli transmodally attract resources, leading to optimized processing of the affective stimuli at the cost of the processing of concurrent stimuli.     

An improved portmanteau test for autocorrelated errors in interrupted time-series regression models

A new portmanteau test for autocorrelation among the errors of interrupted time-series regression models is proposed. Simulation results demonstrate that the inferential properties of the proposed Q(H-M) test statistic are considerably more satisfactory than those of the well known Ljung-Box test and moderately better than those of the Box-Pierce test. These conclusions generally hold for a wide variety of autoregressive (AR), moving averages (MA), and ARMA error processes that are associated with time-series regression models of the form described in Huitema and McKean (2000a, 2000b).     

Age and culture modulate object processing and object—scene binding in the ventral visual area

Behavioral differences in the visual processing of objects and backgrounds as a function of cultural group are well documented. Recent neuroimaging evidence also points to cultural differences in neural activation patterns. Compared with East Asians, Westerners’ visual processing is more object focused, and they activate neural structures that reflect this bias for objects. In a recent adaptation study, East Asian older adults showed an absence of an object-processing area but normal adaptation for background areas. In the present study, 75 young and old adults (half East Asian and half Western) were tested in an fMR-adaptation study to examine differences in object and background processing as well as object—background binding. We found equivalent background processing in the parahippocampal gyrus in all four groups, diminished binding processes in the hippocampus in elderly East Asians and Westerners, and diminished object processing in elderly versus young adults in the lateral occipital complex. Moreover, elderly East Asians showed significantly less adaptation response in the object areas than did elderly Westerners. These findings demonstrate the malleability of perceptual processes as a result of differences in cohort-specific experiences or in cultural exposure over time.     

Police interviewing and psychological vulnerabilities: predicting the likelihood of a confession

This paper is concerned with examining the differences between people who confess and those who deny offences during a police interview. The main hypothesis under investigation is that psychologically vulnerable suspects are particularly likely to confess. This paper is also concerned with identifying variables that might be related to the confession process. One hundred and sixty suspects detained at two London police stations were assessed psychologically prior to being interviewed by the police. The results of this assessment, an analysis of the interview procedure and biographic details were subjected to a logistic regression analysis. There was no evidence to support our main hypothesis. However, suspects were more likely to confess if they reported having consumed an illicit (non-prescribed) drug in the previous 24-hour period, and less likely to confess when interviewed in the presence of a legal adviser or if they had experience of prison or custodial remand. In this study younger suspects were also more likely to confess. © 1998 John Wiley & Sons, Ltd.     

Music while you work: the differential distraction of background music on the cognitive test performance of introverts and extraverts

The current study looked at the distracting effects of ‘pop music’ on introverts' and extraverts' performance on various cognitive tasks. It was predicted that there would be a main effect for music and an interaction effect with introverts performing less well in the presence of music than extraverts. Ten introverts and ten extraverts were given two tests (a memory test with immediate and delayed recall and a reading comprehension test), which were completed, either while being exposed to pop music, or in silence. The results showed that there was a detrimental effect on immediate recall on the memory test for both groups when music was played, and two of the three interactions were significant. After a 6-minute interval the introverts who had memorized the objects in the presence of the pop music had a significantly lower recall than the extraverts in the same condition and the introverts who had observed them in silence. The introverts who completed a reading comprehension task when music was being played also performed significantly less well than these two groups. These findings have implications for the study habits of introverts when needing to retain or process complex information. © 1997 John Wiley & Sons, Ltd.     

The effects of illumination level and retinal size on the depth stratification of subjective contour figures

The apparent stratification in depth of subjective contour figures over their backgrounds was investigated as a function of illumination level, figure size, and viewing distance. Magnitude estimation, with a real contour figure serving as the modulus, was used to measure the stratification in depth of a subjective contour figure over its background. Illumination level and retinal size both had significant effects on the depth stratification of the subjective contour figures. The greatest apparent depth differences were obtained for figures of small retinal size under low levels of illumination. These results paralleled previous findings for judgments of subjective contour strength. Consequently, both contour clarity and depth stratification of subjective contour figures are affected in similar ways by illumination level, figure size, and viewing distance. The implications of this response coupling are discussed in terms of current theories of subjective contours.