Intact attentional control of working memory encoding in schizophrenia

This study reports evidence that individuals with schizophrenia (SC) demonstrate intact attentional selection for visual working memory (WM) storage. A group of 62 participants with SC and 55 control participants without SC were studied in a series of 5 experiments that examined the ability to use top-down and bottom-up cues to guide WM encoding, as well as the ability to spontaneously select a subset of representations for storage. Participants with SC exhibited a consistent and robust ability to use selective attention in the control of WM in all 5 experiments, demonstrating a remarkable island of preserved functioning given the broad spectrum of impairments of attention and WM that have been widely reported in those with SC. These findings indicate that attention is not globally impaired in SC and make it possible to delineate more precisely the nature of the specific impairment of attention in this disorder.     

Deficits on the Continuous Performance Test within the schizophrenia spectrum and the mediating effects of family history of schizophrenia

Individuals with schizophrenia spectrum personality disorders (SSPD) and schizophrenia show similar cognitive impairments. The authors examined the contributions of SSPD symptoms and familial risk for schizophrenia to impairments on the Continuous Performance Test--Identical Pairs Version. Participants included 103 schizophrenia patients, 66 first-degree relatives (29 SSPD), and 103 community controls (26 SSPD) screened for family history of psychosis. Patients and SSPD relatives performed significantly worse than non-SSPD relatives and SSPD and non-SSPD community controls. No differences in performance were observed among non-SSPD relatives and SSPD and non-SSPD community controls. Results suggest a continuum in which risk for schizophrenia-related cognitive impairments is highest among patients and SSPD relatives, intermediate among non-SSPD relatives, and lowest among SSPD and non-SSPD community controls. Results suggest that SSPD in the absence of a family history of psychosis may be a phenocopy.     

The cycle of schizoaffective disorder, cognitive ability, alcoholism, and suicidality

In this study we investigated the putative role of cognitive dysfunction, diagnosis (schizoaffective versus schizophrenia disorder), and alcoholism as risk factors for suicidal behavior among individuals with DSM-TV schizophrenia or schizoaffective disorders. Subjects received cognitive tests and medical records were reviewed for evidence of a history of suicide attempts or suicidal ideation. Discriminant analysis was used to identify cognitive test performance measures that distinguished those with versus those without suicidal behavior. None of the cognitive measures discriminated between the two groups. The rates of suicidal behavior (suicidal ideation and suicide attempts) did not differ between participants with versus those without comorbid alcohol use. An association was found between suicidal behavior and the diagnosis of schizoaffective disorder. It was concluded that the history of prominent mood syndromes characteristic of schizoaffective disorder contributes to increased risk of suicidal behaviors. Cognitive dysfunction and/or alcoholism did not contribute additionally to risk in this study.     

New reflections on visual search: Interitem symmetry matters!

A 90 degrees rotation of a display can turn a relatively easy visual search into a more difficult one. A series of experiments examined the possible causes of this effect, including differences in overall item shape and response mapping (Experiment 1), the interpretation of scene lighting (Experiment 2), the axis of internal symmetry of the search items (Experiment 3), and the axes of interitem symmetry between target and distractor items (Experiment 4). Only the elimination of differences in interitem mirror symmetry resulted in equal search efficiency in the upright and rotated displays. This finding is strong support for the view that visual search is guided by an analysis that considers interitem relations.     

A decision theoretic and prototype conceptualization of possible selves: implications for the prediction of risk behavior

The present study explores a new framework for conceptualizing possible selves for the prediction of behavior. The framework uses decision theory, attitude theory, and classic expectancy-value models. The focus is on using possible-self constructs that (a) correspond to behavioral alternatives, (b) focus on self dimensions directly tied to the behavioral criterion, and (c) use expectancy-value constructs to assess the core features of a given possible self-dimension. A study of 305 college students was undertaken to predict alcohol use from possible self constructs using the framework. Results affirmed the utility of the approach, showing that possible-self constructs predicted behavior over and above current self-image and constructs in the Theory of Planned Behavior. Possible-self constructs associated with negative attributes of both binge drinkers and nonbinge drinkers were predictive of behavior.     

Native Americans and alcohol: past, present, and future

Native Americans have higher rates of alcohol use, frequency of use, and increased rates of fetal alcohol syndrome, compared with other ethnic groups (J. Hisnanick, 1992; P. A. May, 1996; J. M. Wallace et al., 2003). High prevalence rates of alcohol misuse among Native Americans must be understood in light of their unique history, which has resulted in trauma and exposure to many risk factors for problem alcohol use. Many risk factors have been identified in the general population; however, only some of these risk factors have been examined among Native American populations. The unique history and world view of Native Americans mean that, often, risk factors operate differently from the way they do in other populations. The authors discuss interventions and promising treatments.     

Choice between single and multiple reinforcers in concurrent-chains schedules

Pigeons responded on concurrent-chains schedules with equal variable-interval schedules as initial links. One terminal link delivered a single reinforcer after a fixed delay, and the other terminal link delivered either three or five reinforcers, each preceded by a fixed delay. Some conditions included a postreinforcer delay after the single reinforcer to equate the total durations of the two terminal links, but other conditions did not include such a postreinforcer delay. With short initial links, preference for the single-reinforcer alternative decreased when a postreinforcer delay was present, but with long initial links, the postreinforcer delays had no significant effect on preference. In conditions with a postreinforcer delay, preference for the single-reinforcer alternative frequently switched from above 50% to below 50% as the initial links were lengthened. This pattern of results was consistent with delay-reduction theory (Squires & Fantino, 1971), but not with the contextual-choice model (Grace, 1994) or the hyperbolic value-added model (Mazur, 2001) as they have usually been applied. However, the hyperbolic value-added model could account for the results if its calculations were expanded to include reinforcers delivered in later terminal links. The implications of these findings for models of concurrent-chains performance are discussed.     

Construct validity of the Bender-Gestalt II: comparison with Wechsler Intelligence Scale for Children-III

This study investigated the relationships of visuomotor constructs as measured by the Bender-Gestalt II with the subtests of the WISC-III. A factor analysis included the standardized Copy and Recall scores of the Bender-Gestalt II and subtest scores of the WISC-III. The Copy score was predicted to load on measures of visual and spatial thinking and the Recall score on a short-term memory factor. The results of a principal components analysis suggest a four-factor solution with the Bender-Gestalt II Copy score loading on a visual and spatial thinking factor primarily with WISC-III Perceptual Organization subtests. The Recall score loaded on a visual and spatial thinking factor as well as a short-term memory factor with the WISC-III Digit Span subtest. The results suggest the Bender-Gestalt II Copy subtest shared commonality with the visual and spatial tasks given the similarity in the visuomotor demands of each test and was less influenced by processing speed or cultural knowledge than other tests on the visual and spatial thinking factor. Also, results suggest Bender-Gestalt II Recall measures elements of both visual and spatial thinking as well as aspects of short-term memory and memory retrieval. Clinical guidelines for co-administration and underlying processing demands are discussed.     

An analysis of U.S. parachuting fatalities: 2000-2004

Between 2000 and 2004, 125 recreational parachuting fatalities were reported in the USA. Each was categorized using a previously reported taxonomy. While patterns of skydiving fatality were largely unchanged since the last such analysis of fatalities from 1993-1999, some variations were noted. As in previous analyses, most of the recent skydiving fatalities were the direct result of human error. Some examples of commonplace human error fatalities were turning low to the ground resulting in a hard landing, accidentally colliding with other skydivers resulting in entangled parachutes, and failure to deploy the reserve parachute correctly in the event of malfunctioning main parachute.