Intrusive re‐experiencing in post‐traumatic stress disorder: Phenomenology,theory, and therapy

The article describes features of trauma memories in post‐traumatic stress disorder (PTSD), including characteristics of unintentional re‐experiencing symptoms and intentional recall of trauma narratives. Re‐experiencing symptoms are usually sensory impressions and emotional responses from the trauma that appear to lack a time perspective and a context. The vast majority of intrusive memories can be interpreted as re‐experiencing of warning signals, i.e., stimuli that signalled the onset of the trauma or of moments when the meaning of the event changed for the worse. Triggers of re‐experiencing symptoms include stimuli that have perceptual similarity to cues accompanying the traumatic event. Intentional recall of the trauma in PTSD may be characterised by confusion about temporal order, and difficulty in accessing important details, both of which contribute to problematic appraisals. Recall tends to be disjointed. When patients with PTSD deliberately recall the worst moments of the trauma, they often do not access other relevant (usually subsequent) information that would correct impressions/predictions made at the time. A theoretical analysis of re‐experiencing symptoms and their triggers is offered, and implications for treatment are discussed. These include the need to actively incorporate updating information ( “I know now …”) into the worst moments of the trauma memory, and to train patients to discriminate between the stimuli that were present during the trauma ( “then”) and the innocuous triggers of re‐experiencing symptoms ( “now”).     

The effect of working memory load on semantic illusions: What the phonological loop and central executive have to contribute

When asked how many animals of each kind Moses took on the Ark, most people respond with “two” despite the substituted name (Moses for Noah) in the question. Possible explanations for semantic illusions appear to be related to processing limitations such as those of working memory. Indeed, individual working memory capacity has an impact upon how sentences containing substitutions are processed. This experiment examined further the role of working memory in the occurrence of semantic illusions using a dual-task working memory load approach. Participants verified statements while engaging in either articulatory suppression or random number generation. Secondary task type had a significant effect on semantic illusion rate, but only when comparing the control condition to the two dual-task conditions. Furthermore, secondary task performance in the random number generation condition declined, suggesting a tradeoff between tasks. Response time analyses also showed a different pattern of processing across the conditions. The findings suggest that the phonological loop plays a role in representing semantic illusion sentences coherently and in monitoring for details, while the role of the central executive is to assist gist-processing of sentences. This usually efficient strategy leads to error in the case of semantic illusions.     

Effectiveness of online word of mouth on exposure to an Internet-delivered intervention

The use of online word of mouth (WOM) seems a promising strategy to motivate young people to visit Internet-delivered interventions. An Internet-delivered intervention aimed at changing implicit attitudes related to alcohol was used in two experiments to test effectiveness of e-mail invitations on a first visit to the intervention. The results of the first experiment (N = 196) showed that an invitation by e-mail from a friend was more effective to attract young adults (aged 18–24 years) to the intervention website than an invitation from an institution. A 2 × 2 design was used in the second experiment (N = 236) to test manipulations of argument strength and the use of peripheral cues in invitations. Results showed that weak arguments were more effective to attract young adults to the intervention website when an incentive was withheld. These results need to be taken into account when using online WOM as a strategy to improve exposure to Internet-delivered interventions.     

Single-process versus multiple-strategy models of decision making: Evidence from an information intrusion paradigm

When decision makers are confronted with different problems and situations, do they use a uniform mechanism as assumed by single-process models (SPMs) or do they choose adaptively from a set of available decision strategies as multiple-strategy models (MSMs) imply? Both frameworks of decision making have gathered a lot of support, but only rarely have they been contrasted with each other. Employing an information intrusion paradigm for multi-attribute decisions from givens, SPM and MSM predictions on information search, decision outcomes, attention, and confidence judgments were derived and tested against each other in two experiments. The results consistently support the SPM view: Participants seemingly using a “take-the-best” (TTB) strategy do not ignore TTB-irrelevant information as MSMs would predict, but adapt the amount of information searched, choose alternative choice options, and show varying confidence judgments contingent on the quality of the “irrelevant” information. The uniformity of these findings underlines the adequacy of the novel information intrusion paradigm and comprehensively promotes the notion of a uniform decision making mechanism as assumed by single-process models.     

Perceived duration decreases with increasing eccentricity

Previous studies examining the influence of stimulus location on temporal perception yield inhomogeneous and contradicting results. Therefore, the aim of the present study is to soundly examine the effect of stimulus eccentricity. In a series of five experiments, subjects compared the duration of foveal disks to disks presented at different retinal eccentricities on the horizontal meridian. The results show that the perceived duration of a visual stimulus declines with increasing eccentricity. The effect was replicated with various stimulus orders (Experiments 1–3), as well as with cortically magnified stimuli (Experiments 4–5), ruling out that the effect was merely caused by different cortical representation sizes. The apparent decreasing duration of stimuli with increasing eccentricity is discussed with respect to current models of time perception, the possible influence of visual attention and respective underlying physiological characteristics of the visual system.     

Effects of attention on dichotic listening in elderly and patients with dementia of the Alzheimer type

This article presents an overview of our studies in elderly and Alzheimer patients employing Kimura's dichotic digits paradigm as a measure for left hemispheric predominance for processing language stimuli. In addition to structural brain mechanisms, we demonstrated that attention modulates the direction and degree of ear asymmetry in dichotic listening. Elderly showed increasingly more difficulties focusing attention on the left ear (LE) with advancing age. Alzheimer patients showed severe deficits to allocate attention to the LE, which could result in a right ear advantage. These results may be attributed to a breakdown of the cortical attentional network which is mediated by frontal (inhibitory control of attention) and parietal regions (spatial attention and 'disengagement processes'). Both interhemispheric disconnectivity (callosal atrophy) and intrahemispheric disconnectivity (subcortical white matter lesions) appear to be important factors contributing to these findings.     

Intraclass correlation associated with therapists: estimates and applications in planning psychotherapy research

It is essential that outcome research permit clear conclusions to be drawn about the efficacy of interventions. The common practice of nesting therapists within conditions can pose important methodological challenges that affect interpretation, particularly if the study is not powered to account for the nested design. An obstacle to the optimal design of these studies is the lack of data about the intraclass correlation coefficient (ICC), which measures the statistical dependencies introduced by nesting. To begin the development of a public database of ICC estimates, the authors investigated ICCs for a variety outcomes reported in 20 psychotherapy outcome studies. The magnitude of the 495 ICC estimates varied widely across measures and studies. The authors provide recommendations regarding how to select and aggregate ICC estimates for power calculations and show how researchers can use ICC estimates to choose the number of patients and therapists that will optimize power. Attention to these recommendations will strengthen the validity of inferences drawn from psychotherapy studies that nest therapists within conditions.