Nonparticipation in Huntington's Disease Predictive Testing: Reasons for Caution in Interpreting Findings

When given the opportunity to clarify their genetic status, most individuals at risk for Huntington's disease (HD) currently show a preference not to know. Our understanding of the characteristics of those who do not request HD predictive testing, and the factors influencing their decision, lags behind our knowledge of test applicants. In the light of our experience with interviewing a random sample of nonparticipants in an ongoing study, we critically analyze research concerning the differences between participants and nonparticipants in HD predictive testing programs and the interpretive characterization of these two groups. The findings concerning nonparticipants are limited to a small sample of the at-risk population, with the problems of biased samples and low response rates. We discuss this and other aspects of research in this area, notably the context and timing of data collection and the predominantly questionnaire-based methodology, that lead us to interpret the conclusions drawn about these two groups with caution.     

Sustained attention in combat-related posttraumatic stress disorder

There is substantial evidence that PTSD patients have information processing abnormalities for stimuli that are highly relevant to the traumas they have endured. The goal of the present study was to examine whether this extends to neutral stimuli as well. Twenty-four male Vietnam combat veterans with PTSD were compared to fifteen normal male comparison subjects on their performance on a sensitive measure of sustained attention, the Continuous Performance Test-Identical Pairs version (CPT-IP). PTSD subjects did not differ from controls in their ability to discriminate target stimuli from background noise on the CPT. Additionally they performed as well as controls, even in the presence of external distraction. Thus, this study did not find a generalized deficit in attention associated with PTSD on the CPT-IP. Nevertheless, further clarification of the nature of the information processing disturbance in PTSD is warranted.     

Alexander F. Chamberlain: A life’s work

This article examines the life and work of Alexander Francis Chamberlain. Though he has received little attention since the early 1900s, the importance of this scholar should not be underestimated. Chamberlain made notable contributions to the body of knowledge in anthropology—a discipline that, at the time, was a combination of anthropological and psychological inquiry. His early work began with investigations into the cultures and languages of two Indian tribes indigenous to Canada and the northern United States and, within a few decades, positioned Chamberlain as the leading scholar in this domain. Beyond his ethnographic insights, Chamberlain queried the development of the child and wrote on the subject of childhood in world folklore. He concerned himself with a scope of worthwhile subjects ranging from linguistics to women’s suffrage. No topic was out of range as all forms of human study addressed the need for seeing each group as a contributing force to humanity at large. Chamberlain emphasized that no single racial, ethnic, or religious group should be singled out as inherently superior to another, a belief far ahead of his time. This article is an attempt at drawing a picture of a man whose scholarly achievements and strength of character are captured in the depth and breadth of his writing. Reprinted from Jaan Valsiner (ed.).Thinking in Psychological Science: Ideas and Their Makers. Transaction Publishers. Previously published inFrom Past to Future, Vol. 3(1),Passionate Collector: Alexander F. Chamberlain and Child Study, pp. 1–13. @ 2000. Frances L. Hiatt School of Psychology, Clark University. Author: Julia M. Berkman, Department of Psychology, Clark University, 950 Main Street, Worcester, MA.     

Emergence of attributional style and its relation to depressive symptoms

The development of depressive attributional style (AS) and its role as a cognitive diathesis for depression were examined in children and adolescents (Grades 2-9). In a 4-wave longitudinal study of 3 overlapping age cohorts, AS, negative life events, and depressive symptoms were evaluated every 12 months. Consistency of children's attributions across situations was moderately high at all ages. The cross-sectional structure of AS changed with age, as stability became a more salient aspect of AS than internality and globality. The structure of AS also changed, becoming more traitlike as children grew older. In longitudinal analyses, evidence of a Cognitive Diathesis x Stress interaction did not emerge until Grades 8 and 9, suggesting that AS may not serve as a diathesis for depression at younger ages. Results suggest that attributional models of depression may require modification before they are applied across developmental levels.     

Social presence effects on the stroop task: Boundary conditions and an alternative account

Two studies investigated boundary conditions of an effect of social presence on the Stroop task and its interpretation in terms of an attentional view (P. Huguet, M. P. Galvaing, J. M. Monteil, & F. Dumas, 1999). In this view, social presence leads to attentional focusing, enhancing participants’ ability to screen out the distracting features of Stroop stimuli. As predicted, Stroop interference was found to be reduced by social presence, but an alternative account in which social presence exerts an effect on task selection received more support.     

Selective attention and inhibitory deficits in ADHD: Does subtype or comorbidity modulate negative priming effects?

Selective attention has durable consequences for behavior and neural activation. Negative priming (NP) effects are assumed to reflect a critical inhibitory component of selective attention. The performance of adolescents with Attention Deficit/Hyperactivity Disorder (ADHD) was assessed across two conceptually based NP tasks within a selective attention procedure. Comorbidity (non-comorbid ADHD vs. comorbid ADHD) and subtype (ADHD combined vs. ADHD inattentive) were considered key issues. Results found NP effects to differ as a function of comorbidity but not subtype. Findings are discussed in light of functional neuroimaging evidence for neuronal enhancement for unattended stimuli relative to attended stimuli that strongly complements an inhibitory-based explanation for NP. Implications for the ‘AD’ in ADHD and contemporary process models of the disorder are considered.     

Cognitive functioning, behavior, and quality of life after stroke in childhood.

Rationale: To provide a better understanding of cognitive functioning, motor outcome, behavior and quality of life after childhood stroke and to study the relationship between variables expected to influence rehabilitation and outcome (age at stroke, time elapsed since stroke, lateralization, location and size of lesion). Methods: Children who suffered from stroke between birth and their eighteenth year of life underwent an assessment consisting of cognitive tests (WISC-III, WAIS-R, K-ABC, TAP, Rey-Figure, German Version of the CVLT) and questionnaires (Conner's Scales, KIDSCREEN). Results: Twenty-one patients after stroke in childhood (15 males, mean 11;11 years, SD 4;3, range 6;10-21;2) participated in the study. Mean Intelligence Quotients (IQ) were situated within the normal range (mean Full Scale IQ 96.5, range IQ 79-129). However, significantly more patients showed deficits in various cognitive domains than expected from a healthy population (Performance IQ p = .000; Digit Span p = .000, Arithmetic's p = .007, Divided Attention p = .028, Alertness p = .002). Verbal IQ was significantly better than Performance IQ in 13 of 17 patients, independent of the hemispheric side of lesion. Symptoms of ADHD occurred more often in the patients' sample than in a healthy population (learning difficulties/inattention p = .000; impulsivity/hyperactivity p = .006; psychosomatics p = .006). Certain aspects of quality of life were reduced (autonomy p = .003; parents' relation p = .003; social acceptance p = .037). Three patients had a right-sided hemiparesis, mean values of motor functions of the other patients were slightly impaired (sequential finger movements p = .000, hand alternation p = .001, foot tapping p = .043). In patients without hemiparesis, there was no relation between the lateralization of lesion and motor outcome. Lesion that occurred in the midst of childhood (5-10 years) led to better cognitive outcome than lesion in the very early (0-5 years) or late childhood (10-18 years). Other variables such as presence of seizure, elapsed time since stroke and size of lesion had a small to no impact on prognosis. Conclusion: Moderate cognitive and motor deficits, behavioral problems, and impairment in some aspects of quality of life frequently remain after stroke in childhood. Visuospatial functions are more often reduced than verbal functions, independent of the hemispheric side of lesion. This indicates a functional superiority of verbal skills compared to visuospatial skills in the process of recovery after brain injury. Compared to the cognitive outcome following stroke in adults, cognitive sequelae after childhood stroke do indicate neither the lateralization nor the location of the lesion focus. Age at stroke seems to be the only determining factor influencing cognitive outcome.     

Aging affects acquisition and reversal of reward-based associative learning

Reward-based associative learning is mediated by a distributed network of brain regions that are dependent on the dopaminergic system. Age-related changes in key regions of this system, the striatum and the prefrontal cortex, may adversely affect the ability to use reward information for the guidance of behavior. The present study investigated the effects of healthy aging on different components of reward learning, such as acquisition, reversal, effects of reward magnitude, and transfer of learning. A group of 30 young (mean age = 24.2 yr) and a group of 30 older subjects (mean age = 64.1 yr) completed two probabilistic reward-based stimulus association learning tasks. Older subjects showed poorer overall acquisition and impaired reversal learning, as well as deficits in transfer learning. When only those subjects who showed evidence of significant learning were considered, younger subjects showed equivalently fast learning irrespective of reward magnitude, while learning curves in older subjects were steeper for high compared to low reward magnitudes. Acquired equivalence learning, which requires generalization across stimuli and transfer of learned contingencies to new stimuli, was mildly impaired in older subjects.