The police officer's dilemma: using ethnicity to disambiguate potentially threatening individuals

Using a simple videogame, the effect of ethnicity on shoot/don't shoot decisions was examined. African American or White targets, holding guns or other objects, appeared in complex backgrounds. Participants were told to "shoot" armed targets and to "not shoot" unarmed targets. In Study 1, White participants made the correct decision to shoot an armed target more quickly if the target was African American than if he was White, but decided to "not shoot" an unarmed target more quickly if he was White. Study 2 used a shorter time window, forcing this effect into error rates. Study 3 replicated Study 1's effects and showed that the magnitude of bias varied with perceptions of the cultural stereotype and with levels of contact, but not with personal racial prejudice. Study 4 revealed equivalent levels of bias among both African American and White participants in a community sample. Implications and potential underlying mechanisms are discussed.     

Tactile "capture" of audition

Previous research has demonstrated that the localization of auditory or tactile stimuli can be biased by the simultaneous presentation of a visual stimulus from a different spatial position. We investigated whether auditory localization judgments could also be affected by the presentation of spatially displaced tactile stimuli, using a procedure designed to reveal perceptual interactions across modalities. Participants made left-right discrimination responses regarding the perceived location of sounds, which were presented either in isolation or together with tactile stimulation to the fingertips. The results demonstrate that the apparent location of a sound can be biased toward tactile stimulation when it is synchronous, but not when it is asynchronous, with the auditory event. Directing attention to the tactile modality did not increase the bias of sound localization toward synchronous tactile stimulation. These results provide the first demonstration of the tactile capture of audition.     

Reaction time slowing in adults with HIV: results of a meta-analysis using brinley plots

A meta-analysis in the form of Brinley plots was conducted on the mean reaction times of HIV+ and HIV- groups. HIV+ reaction times were regressed on HIV- reaction times across 122 task conditions from 29 studies, producing a highly linear function (r(2) = .94), with a slope b = 1.039, which was not significantly different than b = 1.00. Asymptomatic and symptomatic HIV+ reaction times were also separately regressed on HIV- reaction times across 67 task conditions from 13 studies. Both functions were highly linear (r(2) = .97 and.90 respectively), with slopes of 1.034 and 1.117 respectively. Only the slope for symptomatic HIV+ groups was significantly larger than b = 1.00, suggesting a modest generalized slowing of cognition in these adults.     

Action-based and vision-based selection of input: Two sources of control

In the first part of this paper we review evidence suggesting that there exists a mechanism that selects input on the basis of its similarity to the required action. This response-based input selection differs from the more established space- and object-based input selection in that it is not constrained by the structure of the input. Our evidence suggests that the two-choice Stroop effect is caused by this response-based selection mechanism. By contrast, it is known that the flanker effect is determined by the space- and object- based selection mechanisms. We explore whether the conflict resolution of the Stroop and flanker tasks is different as well by embedding these two tasks in a PRP (Psychological Refractory Period) paradigm. We show that the Stroop and the PRP effects are additive whereas the flanker and the PRP effects are underadditive, suggesting that the processes in charge of the conflict resolution in the Stroop and the flanker tasks are indeed different. We discuss possible reasons for this difference, and discuss possible ways in which the response-based mechanism can be implemented in information processing models.     

Differential functioning of the Beck depression inventory in late-life patients: use of item response theory

The present analyses examined age-related measurement bias in responses to items on the revised Beck Depression Inventory (BDI) in depressed late-life patients versus midlife patients. Item response theory (IRT) models were used to equate the scale and to differentiate true-group differences from bias in measurement in the 2 samples. Baseline BDI data (218 late life and 613 midlife) were used for the present analysis. IRT results indicated that late-life patients tended to report fewer cognitive symptoms, especially at low to average levels of depression. Conversely, they tended to report more somatic symptoms, especially at higher levels of depression. Adjusted cutoff scores in the late-life group are provided, and possible reasons for age-related differences in the performance of the BDI are discussed.     

A crossmodal attentional blink between vision and touch

There is currently a great deal of interest regarding the possible existence of a crossmodal attentional blink (AB) between audition and vision. The majority of evidence now suggests that no such crossmodal deficit exists unless a task switch is introduced. We report two experiments designed to investigate the existence of a crossmodal AB between vision and touch. Two masked targets were presented successively at variable interstimulus intervals. Participants had to respond either to both targets (experimental condition) or to just the second target (control condition). In Experiment 1, the order of target modality was blocked, and an AB was demonstrated when visual targets preceded tactile targets, but not when tactile targets preceded visual targets. In Experiment 2, target modality was mixed randomly, and a significant crossmodal AB was demonstrated in both directions between vision and touch. The contrast between our visuotactile results and those of previous audiovisual studies is discussed, as are the implications for current theories of the AB.     

Postmodernism Versus Modernism: Rethinking Theoretical Tensions in Social Gerontology

The interconnection of social theory to social aspects of aging has grown in recent years. The theoretical movement entitled structured dependency, couched in social class analysis, has tended to ignore an understanding of aging identity, the body, cultural representations of aging, and positive images of aging, all of which are central features of an emerging postmodern paradigm in gerontological theory. This article argues that the concept of gender can form a useful bridge, a continuity, between structured dependency and postmodernism in theoretical gerontology. Unfortunately, the compartmentalization of these two conceptual approaches has made their links difficult to forge. This article attempts to take a first step in this direction by highlighting the way postmodern ideas can be used to understand a modernist issue—gender in a gerontological context. Also, focusing on the aging body as a primary form of analysis generates some novel insights into the importance of both the theoretical understanding and cultural representations of the body.     

The priority of just-identified,recursive models

Theories often place constraints on causal relationships, and such constraints are often assessed with causal models. Causal models should be recursive and just identified because cause is recursive and is more likely to be just identified than overidentified. A just-identified, recursive model (JIRM) is specified that satisfies both requirements and that can be used to assess a wide range of causal implications in either a norm-referenced or criterion-referenced manner. P. E. Meehl and N. G. Waller (2002) proposed an innovative method for theory appraisal called the delete one-add one (D1-A1) method, which assesses a relatively narrow range of causal implications, allows nonrecursive models, and is only norm referenced. The JIRM and D1-A1 methods are compared.     

Win-shift and win-stay learning in the short-beaked echidna (<Emphasis Type="Italic">Tachyglossus aculeatus</Emphasis>)

Numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval results do not. Electronic Publication     

The research subject as wage earner

Theoretical Medicine and Bioethics - The practice of paying research subjects for participating inclinical trials has yet to receive an adequate moral analysis.Dickert and Grady argue for a wage...