Cognitive Testing Battery: differences among groups with dementia, Huntington's disease, and controls

This study evaluated a new test for dementia, the Cognitive Testing Battery, used for over six years in outpatient clinics for aging-related disorders. This battery was developed to be brief, easy to administer, and to provide useful feedback as a cognitive profile for clinicians, patients, and caregivers. 489 participants were tested during a 5-yr. period. Multidisicplinary teams diagnosed these patients with dementia, depression, or Huntington's Disease. A control group was also included. Groups were then compared on the 10 key subscales that subserve dementia populations. Analysis showed there were significant differences among the groups on all measures and that selected scales differentiated the groups. The total score maximally differentiated the groups, and the dementia group was most different from the other groups.     

Directional harmonic theory: a computational Gestalt model to account for illusory contour and vertex formation

Visual illusions and perceptual grouping phenomena offer an invaluable tool for probing the computational mechanism of low-level visual processing. Some illusions, like the Kanizsa figure, reveal illusory contours that form edges collinear with the inducing stimulus. This kind of illusory contour has been modeled by neural network models by way of cells equipped with elongated spatial receptive fields designed to detect and complete the collinear alignment. There are, however, other illusory groupings which are not so easy to account for in neural network terms. The Ehrenstein illusion exhibits an illusory contour that forms a contour orthogonal to the stimulus instead of collinear with it. Other perceptual grouping effects reveal illusory contours that exhibit a sharp corner or vertex, and still others take the form of vertices defined by the intersection of three, four, or more illusory contours that meet at a point. A direct extension of the collinear completion models to account for these phenomena tends towards a combinatorial explosion, because it would suggest cells with specialized receptive fields configured to perform each of those completion types, each of which would have to be replicated at every location and every orientation across the visual field. These phenomena therefore challenge the adequacy of the neural network approach to account for these diverse perceptual phenomena. I have proposed elsewhere an alternative paradigm of neurocomputation in the harmonic resonance theory (Lehar 1999, see website), whereby pattern recognition and completion are performed by spatial standing waves across the neural substrate. The standing waves perform a computational function analogous to that of the spatial receptive fields of the neural network approach, except that, unlike that paradigm, a single resonance mechanism performs a function equivalent to a whole array of spatial receptive fields of different spatial configurations and of different orientations, and thereby avoids the combinatorial explosion inherent in the older paradigm. The present paper presents the directional harmonic model, a more specific development of the harmonic resonance theory, designed to account for specific perceptual grouping phenomena. Computer simulations of the directional harmonic model show that it can account for collinear contours as observed in the Kanizsa figure, orthogonal contours as seen in the Ehrenstein illusion, and a number of illusory vertex percepts composed of two, three, or more illusory contours that meet in a variety of configurations.     

A methodology for describing and decomposing complex psychosocial and behavioral interventions

This article presents a comprehensive conceptual framework and methodology for characterizing multidimensional psychosocial and behavioral interventions for family caregivers of people with Alzheimer's disease. The methodology involved conducting a detailed task analysis of the interventions, and the application of the analytical hierarchy process. The authors were able to achieve high levels of consistency and reliability using this methodology to decompose and describe the interventions according to a complex conceptual framework comprising 3 dimensions: target domain, functional domain, and delivery system characteristics. Application of this methodology will enhance the ability to describe and measure interventions consistently, make comparisons across studies, isolate causal factors that achieve desired outcomes, and more generally elevate the science of psychosocial intervention research.     

Dissociations among attention, perception, and awareness during object-substitution masking

When a visual target object is surrounded by four dots that onset at the same time as the target but remain visible after the target terminates, the four dots dramatically impair target discrimination performance. This phenomenon is called object-substitution masking , reflecting the hypothesis that both the target and the four dots are identified, but the representation of the four dots replaces the representation of the target object before the target can be reported. The present study used the event-related potential technique to demonstrate that a target masked in this manner is identified by the visual system and triggers a shift of attention. However, by the time attention is shifted to the target, only the mask remains visible, leading to impaired behavioral detection performance. These findings support the object-substitution hypothesis and provide new evidence that perception, attention, and awareness can be dissociated.     

Divergent ethical perspectives on the duty-to-warn principle with HIV patients

This article presents the case of an HIV-positive client who reported having sexual relations with an unknowing partner. The issue raised is whether the therapist was required to warn the unknowing partner, similar to the Tarasoff mandate that is imposed on therapists. The case is analyzed from an ethical framework similar to that presented by Beauchamp and Childress (1994). Two opinions are presented, each leading to different conclusions about whether the therapist should inform the unknowing partner. It is concluded that although such analysis is valuable in aiding the therapist in his or her decision-making process, no clear professional standard for the management of the problem is evident.     

Examining the construct validity of the Eating Disorder Inventory

The construct validity of the Eating Disorder Inventory (EDI) was examined in 3 samples. An archival clinic sample (n = 318) of women completed the EDI, a structured interview, and the Millon Clinical Multiaxial Inventory-II (MCMI-II). Confirmatory factor analyses (CFAs) indicated that neither null nor 1-factor models of the EDI fit item-level or item-parcel data. The proposed 8-factor model did not fit at the item level but did fit item-parcel data. Reliability estimates of the 8 scales ranged from .82 to .93, and low-to-moderate interscale correlations among the eating and weight-related scales provided partial support for convergent validity. EDI personality scales showed moderate interscale correlations and were associated with MCMI-II scales. A final CFA of the EDI scales supported a 2-factor model (Eating and Weight, Personality) of the 8 EDI scales. Strong associations between depression and several EDI scale scores were found in a treatment study sample (n = 50). The archival clinic sample scored significantly higher on the 8 EDI scales than the nonpatient college comparison sample (n = 487).     

Perceptual organization influences visual working memory

Previous studies have demonstrated that top-down factors can bias the storage of information in visual working memory. However, relatively little is known about the role that bottom-up stimulus characteristics play in visual working memory storage. In the present study, subjects performed a change detection task in which the to-be-remembered objects were organized in accordance with Gestalt grouping principles. When an attention-capturing cue was presented at the location of one object, other objects that were perceptually grouped with the cued object were more likely to be stored in working memory than were objects that were not grouped with the cued object. Thus, objects that are grouped together tend to be stored together, indicating that bottom-up perceptual organization influences the storage of information in visual working memory.     

Emerging therapeutics for Alzheimer's disease: an avenue of hope

Emerging therapies for Alzheimer's disease offer hope to patients and their caregivers. Future treatments will probably include combination approaches with agents that modify amyloid processing, deposition, and clearance. One example, the AD vaccine, reduced amyloid burden and changed behavior in animal models of AD, but the human trial was halted when several subjects developed brain inflammation. Anti-inflammatory agents have epidemiologic support, but clinical trials have been disappointing, possibly related to inadequate study with anti-inflammatory agents that modify amyloid processing. Agents that target known cardiovascular risk factors, such as hypercholesterolemia, hypertension, and insulin resistance, have epidemiologic, preclinical, and clinical evidence to warrant further investigation. Heavy metal chelators, antioxidants, neurotrophic factors, glutaminergic modulators, and agents that modify hyperphosphorylation of Tau are other approaches in research and development.     

Boredom proneness and sleep disorders as predictors of adult attention deficit scores

This study examined the extent to which boredom proneness and sleep disturbances were related to attention deficit scores in college-aged adults. In a sample of 148 college students, Attention scores on the Adult Behavior Checklist were best predicted by Boredom Proneness (BP) subscale scores, which assess one's inability to maintain internal stimulation and feelings of constraint, and scores on the Epworth Daytime Sleepiness Scale and Athens Insomnia Scale (R2 = .57). Hyperactivity scores were best predicted by the BP subscales, which assess one's need for a stimulating environment, the perception of time passing slowly, and feelings of constraint, and the Epworth Scale (R2 = .51). The findings contribute to the understanding of the symptomatology of attention deficit in adults and provide further evidence of the validity of this measure.     

Children Exposed to Community Violence: The Rationale for Early Intervention

Children are exposed to violence in their homes and communities at extraordinarily high rates. Given the alarming rates of exposure and its known impact on child developmental outcomes, crisis intervention geared at interrupting the negative effects of violence exposure are increasingly important. This review provides a rationale for the implementation of early and crisis intervention strategies for children exposed to community violence and recommends principles for applying these interventions. These principles are based on the body of research concerning risk and protective factors for children who have been exposed to violence. Relevant factors are reviewed and recommended principles are explicated that correlate to these factors. Issues concerning developmentally informed crisis intervention, support of parental executive functioning, and the need for active community partnership to help ameliorate risk factors are highlighted.