Frontal-Lobe Involvement in Spatial Memory: Evidence from PET,fMRI, and Lesion Studies

Many studies have identified the prefrontal cortex as the brain area that is critical for spatial memory, both in humans and in other primates. Other studies, however, have failed to establish this relation. Therefore, the aim of this paper was to review the literature regarding the role of the human prefrontal lobe in spatial memory. This was done by examining the evidence obtained from neuropsychological patients and from studies using brain-imaging techniques (PET and fMRI). Evidence supporting the notion that the prefrontal cortex is extensively involved in spatial working memory was found. The majority of these studies, however, suggests that frontal-lobe involvement is not related to the type of material that is being processed (e.g., spatial vs. nonspatial), but to process-specific functions, such as encoding and retrieval. Theoretically, these functions could be linked to the central executive within Baddeley's working-memory model, or to recent theories that emphasize the various processes that play a role in working memory. Also, methodological issues were discussed. Further research is needed to enhance our understanding of the precise interaction of domain-specific and general processes.     

Exploring the effects of icon characteristics on user performance: the role of icon concreteness, complexity, and distinctiveness

Because icons, signs, and symbols are now widely used to communicate information, it is essential for system designers to know what makes them easy to use and interpret. The authors report a series of studies that examine characteristics considered central to icon usability. After quantifying the properties of icon concreteness, complexity, and discriminability, the authors assessed each property's effects on user performance when user experience, task demands, and presentation context were systematically varied. Findings indicated that the effects of icon concreteness were primarily associated with the initial grasp of meaning, whereas complexity effects were found to persist longer and to be associated with search efficacy. The effects of icon distinctiveness were complex, but distinctiveness was enhanced by using both semantic and visual contrasts. The implications of these findings for interface design are discussed.     

Dyskinesias differentiate autistic disorder from catatonia

Autistic disorder and catatonia are neuropsychiatric syndromes defined by impairments in social interaction, communication, and restricted, stereotypical motor routines. Assessments of children with these disorders are typically restricted in scope by the patients' limited ability to comprehend directions. The authors performed systematic assessments of dyskinesias on six prepubertal boys with autistic disorder and mental retardation and on one adolescent male with catatonia to determine if this type of information could be routinely obtained. The boys with autistic disorder had more stereotypies and tics, a greater degree of akathisia and hyperactivity, and more compulsions than the adolescent with catatonia. Catatonia was associated with catalepsy and dystonic postures. The authors conclude that the diagnostic accuracy and specificity of neuropsychiatric syndromes may be enhanced by the systematic assessment of the dyskinesias associated with each condition.     

Counterconditioning in the treatment of spider phobia: effects on disgust, fear and valence

From the perspective that disgust is a core feature of spider phobia, we investigated whether the treatment efficacy could be improved by adding a counterconditioning procedure. Women with a clinically diagnosed spider phobia (N = 34) were randomly assigned to the regular one-session exposure condition (EXP) or to the exposure with counterconditioning condition (CC). In the CC-condition tasty food-items were used during the regular exposure exercises and the participants' favourite music was played. Both treatment conditions appeared very effective in reducing avoidance behaviour and self-reported fear of spiders, strongly attenuated the disgusting properties of spiders and altered the affective evaluations in a positive direction. CC was not more effective in altering the affective valence of spiders than EXP and was not superior with respect to the long term treatment efficacy at 1 year follow up. Apparently, regular exposure treatment is already quite effective in altering the affective-evaluative component of spider phobia and it remains to be seen whether it is possible to further improve treatment outcome by means of procedures which are specifically designed to reduce the spiders' negative affective valence.     

Emotions in solution-focused therapy: a re-examination

This article re-examines whether and how emotions are an aspect of solution-focused therapy. A major theme in the article focuses on the usual ways that therapists define and discuss emotions in solution-focused and other therapies. We argue that these discussions are a source of much confusion about emotions and about solution-focused therapy, including the confusing idea that emotions are neglected in solution-focused therapy. The second major theme describes an alternative approach to these issues, one that we believe better fits with the assumptions and concerns of solution-focused therapy. The approach is based on Wittgenstein's writings about language games, private experience, and how emotions are rule-following activities. Viewed from this perspective, solution-focused therapists take account of their clients' emotions by helping clients to create new emotion rules to follow.     

Personality disorders in a Dutch forensic psychiatric sample: convergence of interview and self-report measures

Convergence of PDQ-R- and SIDP-R-derived personality disorder diagnoses was studied in a sample of 85 forensic psychiatric patients. For categorical diagnoses, the mean kappa was .34, but on a dimensional level convergence was somewhat higher. Paranoid, antisocial and borderline personality disorders had prevalence rates around 40%; the other personality disorders occurred with much lower frequency. The PDQ-R yielded more diagnoses, except for antisocial, histrionic, narcissistic, and sadistic personality disorder. Because the latter disorders are among the most prevalent in forensic settings, and because they have important risk and treatment implications, the PDQ-R is not suitable as a screening device in forensic populations. Semistructured interviews that make use of collateral information are recommended for diagnosing personality disorders in forensic subjects.     

In search of remembrance: evidence for memory in visual search

Observers searched for a target among distractors while the display items traded places every 110 ms. Search was slower when the target was always relocated to a position previously occupied by a distractor than when the items remained in place, showing the importance of memory for locations in a visual search task. Experiment 2 repeated a previous study in which items could move to any location within the display, but used a larger range of set sizes than tested in the earlier study. A cost in search times to relocating items was found at the larger set sizes, most likely reflecting that the probability that the target would replace a distractor increased witht he set size. The findings provide strong evidence for the role of memory for locations within trials in a visual search task.     

Optimistic bias among potential perpetrators and victims of youth violence

This study furthers the current understanding of optimistic bias regarding youth violence among high school students. Results from a survey of 387 urban high school students indicate a wide range of predictors of optimistic bias, including experience, demographics, and attitudes. Linkages to other developmental frameworks (personal fable and self-efficacy) suggest future directions for additional research.     

Family functioning and early onset of sexual intercourse in Latino adolescents

The purpose of this study was to identify factors associated with early onset of sexual intercourse. Within an ecological system's conceptual framework, familial factors associated with early onset of sexual activity were identified in a sample of 425 adolescents from San Juan metro area schools. Measures included questions about sexual activity, sexual permissiveness, and such familial variables as: discipline, parental supervision, and parental support. Significant relationships were observed between early onset of sexual intercourse and parental supervision, discipline, parental support, and parents' marital status. Results suggest the key role of parents and family in prevention of HIV-risk behaviors among adolescents in terms of delaying sexual onset. Overall, the study described youths who postponed sexual activity as having greater support, supervision, and parental involvement.