Autobiographical memory in posttraumatic stress disorder before and after treatment

Although overgeneral retrieval of autobiographical memories has been repeatedly demonstrated in posttraumatic stress disorder (PTSD), no studies have indexed overgeneral retrieval before and after treatment of PTSD. Autobiographical memory was assessed in PTSD participants (n=20) prior to commencing cognitive behaviour therapy and 6 months after therapy completion. Fifteen participants completed both assessments. Improvement in PTSD symptoms was significantly associated with improved retrieval of specific memories and decreased retrieval of categoric memories in response to positive cues. These data suggest that symptom reduction during treatment of PTSD leads to greater access to specific memories of positive experiences.     

A prospective study of appraisals in childhood posttraumatic stress disorder

This study investigated the predictors of posttraumatic stress disorder (PTSD) in children following a diagnosis of traumatic injury. Children (N=76) aged between 7 and 13 who were admitted to hospital following injury were assessed within a month of trauma for acute stress disorder (ASD), negative appraisals, as well as parental stress reactions. Children (N=62) were re-assessed 6-months later for PTSD and negative appraisals. The majority of the variance of chronic posttraumatic stress was accounted for by negative appraisals about future harm. This study supports cognitive models of PTSD, and suggests that younger children who exaggerate their vulnerability after trauma exposure are high risk for PTSD after trauma.     

Increased brain serotonin turnover in panic disorder patients in the absence of a panic attack: reduction by a selective serotonin reuptake inhibitor

Since the brain neurotransmitter changes characterising panic disorder remain uncertain, we quantified brain noradrenaline and serotonin turnover in patients with panic disorder, in the absence of a panic attack. Thirty-four untreated patients with panic disorder and 24 matched healthy volunteers were studied. A novel method utilising internal jugular venous sampling, with thermodilution measurement of jugular blood flow, was used to directly quantify brain monoamine turnover, by measuring the overflow of noradrenaline and serotonin metabolites from the brain. Radiographic depiction of brain venous sinuses allowed differential venous sampling from cortical and subcortical regions. The relation of brain serotonin turnover to serotonin transporter genotype and panic disorder severity were evaluated, and the influence of an SSRI drug, citalopram, on serotonin turnover investigated. Brain noradrenaline turnover in panic disorder patients was similar to that in healthy subjects. In contrast, brain serotonin turnover, estimated from jugular venous overflow of the metabolite, 5-hydroxyindole acetic acid, was increased approximately 4-fold in subcortical brain regions and in the cerebral cortex (P < 0.01). Serotonin turnover was highest in patients with the most severe disease, was unrelated to serotonin transporter genotype, and was reduced by citalopram (P < 0.01). Normal brain noradrenaline turnover in panic disorder patients argues against primary importance of the locus coeruleus in this condition. The marked increase in serotonin turnover, in the absence of a panic attack, possibly represents an important underlying neurotransmitter substrate for the disorder, although this point remains uncertain. Support for this interpretation comes from the direct relationship which existed between serotonin turnover and illness severity, and the finding that SSRI administration reduced serotonin turnover. Serotonin transporter genotyping suggested that increased whole brain serotonin turnover most likely derived not from impaired serotonin reuptake, but from increased firing in serotonergic midbrain raphe neurons projecting to both subcortical brain regions and the cerebral cortex.     

Evaluation of the Dispositional Hope Scale in injury survivors

Hope is a higher-order cognitive construct that encompasses the belief in one’s ability to accomplish personal goals. Hope has been conceptualised as consisting of two constructs – Pathways (the individual’s perceived means available to achieve goals) and Agency (belief in ones ability to succeed in using the identified Pathways). This study aimed to validate a measure of hope, the Dispositional Hope Scale (DHS: [Snyder, C. R., Harris, C., Anderson, J. R., Holleran, S. A., Irving, L. M., Sigman, S. T., et al. (1991). The will and the ways: Development and validation of an individual differences measure of hope. Journal of Personality and Social Psychology, 60(4), 570–585]) in a large sample of traumatic injury survivors (N = 1025). The findings support the psychometric properties of the scale, as well as the two-factor structure of Agency and Pathways, in this population. This study provides support for the use of the DHS as a measure of hope in traumatised populations.     

Comprehension skill, inference-making ability, and their relation to knowledge

In this study we investigated the relation between young children's comprehension skill and inference-making ability using a procedure that controlled individual differences in general knowledge (Barnes & Dennis, 1998; Barnes, Dennis, & Haefele-Kalvaitis, 1996). A multiepisode story was read to the children, and their ability to make two types of inference was assessed: coherence inferences, which were essential for adequate comprehension of the text, and elaborative inferences, which enhanced the text representation but which were not crucial to understanding. There was a strong relation between comprehension skill and inference-making ability even when knowledge was equally available to all participants. Subsidiary analyses of the source of inference failures revealed different underlying sources of difficulty for good and poor comprehenders.     

The effect of spatial cues on infants’ responses in the AB task,with and without a hidden object

The errors made by infants in the AB task were taken by Piaget as an indication of an inability to update their representations of the spatial location of a hidden object. This paper presents an experiment designed to further investigate the role of spatial representations in the production of the error. The introduction of strong visual cues to spatial location was found to reduce the traditional A‐not‐B search error. However, it also increased perseveration when a ‘lids‐only’ analogue of the AB task was used, in which infants are simply cued to pick up lids rather than encouraged to search for a hidden object. These results present a challenge to the dynamic systems account of the error given by Smith, Thelen, Titzer and McLin (Psychological Review, 106 (1999), 235–260), and indicate that the traditional A‐not‐B search error arises from a difficulty in updating representations of the spatial location of hidden objects. The relation of these results to Munakata’s PDP model (Developmental Science, 1 (1998), 161–211) and Thelen, Schöner, Scheier and Smith’s (Behavioural and Brain Sciences, 24 (2001), 1‐‐86) most recent dynamic systems model of the A‐not‐B error is also discussed.     

Classifying simulated air threats with fast and frugal heuristics

In three experiments, subjects learned to classify simulated aircraft using four probabilistic cues then classified test sets designed to contrast predictions of several compensatory and non-compensatory heuristics. Results indicated that a proportion of subjects appeared to use a non-compensatory fast and frugal heuristic but that significant proportions used less frugal compensatory decision rules. The relative proportions of subjects exhibiting responses consistent with the fast and frugal heuristic versus other decision rules was largely unaffected by manipulations of time pressure and perceived cue uncertainty. An extreme time constraint, however, did result in significant differences in the proportions of subjects who preferred non-compensatory to compensatory decision rules. These results suggest that it is possible to model multi-attribute decision tasks like threat assessment with a fast and frugal heuristic although no single heuristic is a general model for the simulated threat assessment task. Copyright © 2006 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.     

Monitoring of comprehension: The role of text difficulty in metamemory for narrative and expository text

The effect of text difficulty on metamemory for narrative and expository text was investigated. In Experiment 1, we found an interaction between type of text and type of question (thematic or detailed). For readers of narrative texts, correlations between predicted and actual performance were highest for detailed questions, but this pattern was reversed for readers of expository texts. Next, text difficulty was explored as a possible factor affecting metamemory accuracy. In Experiments 2 and 3, metamemory accuracy was a nonmonotonic function of text difficulty. Subjects made remarkably accurate predictions of future performance (meanG > .6) for both narrative and expository texts that were of intermediate difficulty (approximately a 12th-grade reading level). We propose anoptimum effort hypothesis, predicting greatest metamemory accuracy when the texts are of intermediate difficulty.     

Suicidal behavior among youth with severe emotional disturbance

The purpose of this study was to replicate an investigation of risk behaviors associated with suicidal behavior in public high school students, in a population of high school age youth with severe emotional disturbance (SED). Subjects for the study were clients of the South Carolina Continuum of Care (COC) (N=83). Information on suicidal thoughts and acts, aggressive behaviors, substance use and physical recklessness was gathered using a modified version of the self-report National Youth Risk Behavior Survey. Four percent of the youth reported seriously considering suicide, 8% reported planning how they would attempt suicide, 10% reported actually attempting suicide at least once, and 6% reported attempts requiring medical treatment Of the 13 youth who reported attempting suicide, four (31%) did not report planning an attempt. All suicidal behaviors except thoughts occurred more in girls than boys with SED. Alcohol and illicit drug use were associated with suicidal behavior, with larger odds ratios for attempts than for thoughts/plans. Youth with SED who use alcohol and illicit substances are particularly at risk of suicidal behavior. A high index of suspicion is appropriate when evaluating suicidal risk in girls with SED, especially in the presence of known alcohol or substance use.Continuum of Care for Emotionally Disturbed Children Division, S. C. Office of the Governor.