Within-person variability in response speed as an indicator of cognitive impairment in older adults

Within-person variability may be an important indicator of central nervous system compromise. In this study, within-person variability in response speed was examined in community-dwelling older adults, ages 64-92 years, using a new framework that takes into account both the extent (single versus multiple domains affected) and nature (amnestic versus non-amnestic) of the cognitive impairment. Those with multiple domains of impairment were more variable than those who showed an isolated area of impairment, regardless of whether memory was one of the domains affected. Further, for those with difficulties in two or more non-memory domains, increased variability was most evident in more cognitively demanding situations, when individuals had to manipulate information held briefly in mind, switch cognitive set or inhibit an automatic response. Finally, group differentiation was better achieved when within-person variability as opposed to mean speed of performance was considered.     

Visual Signal Detection Measured by Event-Related Potentials

Signal Detection tasks typically involve within-subject signal changes. Such a procedure does not lend itself to event-related potential (ERP) experiments where the need for averaging necessitates the maintenance of consistent stimulus parameters. In the present ERP study we adopt a novel approach to thresholding that allows within-subject signal manipulation. The Signal Detection task required the identification of letter targets, formed from dots, in a random dot field. ERP waveforms were segmented into three windows corresponding to N1, N2, and P300 components. Analysis shows that ERP variations are dependent on both task demands and response characteristics for N1, N2, and P300 components.     

Memory Development in Children: Implications for Children as Witnesses in Situations of Possible Abuse

This article reviews the physiological constructs of memory development as they relate to a child's ability to recall accurately detailed accounts of sexual abuse. Counselors are provided with practical suggestions for increasing the reliability of child witnesses.     

Comparison of male and female junior athletes' self-perceptions and body image.

Few studies have examined sex differences in body perceptions in sports where the pressure to display a certain physique is reduced. The aim of the present study was to investigate sex differences in physical self-perceptions and body image in junior athletes who are involved in sprint kayaking, a sport where a low body weight is relatively unimportant. 12 male and 13 female members (aged 13-17 yr.) of the British Canoe Union Junior Development Squad for sprint-kayak racing completed the Physical Self-perception Profile for Children and the Multidimensional Body-Self Relations Questionnaire. Multivariate analysis of variance indicated that girls reported significandy higher Sports Competence and lower Appearance Orientation scores than boys. This study has raised a number of issues surrounding the physical self-perceptions and body image of junior athletes involved in a power- and strength-based sport. It seems that male athletes may also experience pressures to conform to a male version of a 'beautiful body'.     

A Big Regulatory Tool-Box for a Small Technology

There is little doubt that the development and commercialisation of nanotechnologies is challenging traditional state-based regulatory regimes. Yet governments currently appear to be taking a non-interventionist approach to directly regulating this emerging technology. This paper argues that a large regulatory toolbox is available for governing this small technology and that as nanotechnologies evolve, many regulatory advances are likely to occur outside of government. It notes the scientific uncertainties facing us as we contemplate nanotechnology regulatory matters and then examines the notion of regulation itself, suggesting new ways to frame our understanding of both regulation and the regulatory tools relevant to nanotechnologies. By drawing upon three different conceptual lenses of regulation, the paper articulates a wide range of potential regulatory tools at hand. It also focuses particularly on the ways various tools are currently being used or perhaps may be employed in the future. The strengths and weaknesses characterising these tools is examined as well as the different actors involved. The paper concludes that we will increasingly face debate over what is likely to work most effectively in regulating nano technologies, the legitimacy of these different potential approaches, and the speed at which these different regimes may be employed.

Effects of absolute luminance and luminance contrast on visual discrimination in low mesopic environments

Recent research revealed considerable decline in visual perception under low luminance conditions. However, systematic studies on how visual performance is affected by absolute luminance and luminance contrast under low mesopic conditions (<0.5 cd/m²) is lacking. We examined performance in a simple visual discrimination task under low mesopic luminance conditions in three experiments in which we systematically varied base luminance and luminance contrast between stimulus and background. We further manipulated eccentricity of the stimuli because of known rods and cones gradients along the retina. We identified a “deficiency window” for performance as measured by d’ when luminance was < 0.06 cd/m² and luminance contrast as measured by the luminance ratio between stimulus and background was below < 1.7. We further calculated performance-based luminance as well as contrast efficiency functions for reaction times (RTs). These power functions demonstrate the contrast asymptote needed to decrease RTs and how such a decrease can be achieved given various combinations of absolute luminance and luminance contrast manipulations. Increased eccentricity resulted in slower RTs indicative of longer scan distances. Our data provide initial insights to performance-based efficiency functions in low mesopic environments that are currently lacking and to the physical mechanisms being utilized for visual perception in these extreme environments.     

Measuring illness representations in breast cancer survivors (BCS) prescribed tamoxifen: Modification and validation of the Revised Illness Perceptions Questionnaire (IPQ-BCS)

Objective: The Revised Illness Perceptions Questionnaire (IPQ-R), widely used to assess illness perceptions, may fail to measure unique characteristics of different illnesses. This study modified and validated the IPQ-R for breast cancer survivors to provide detailed understanding of the specific illness perceptions held by these patients.

Design: Initial modifications were made following qualitative interviews and were revised in a think-aloud study. The modified scale was tested in 753 breast cancer survivors prescribed tamoxifen. Modifications included adding a tamoxifen consequences scale and adapting the timeline scales to measure beliefs around risk of recurrence and cure. A confirmatory factor analysis was conducted on the modified questionnaire and an exploratory factor analysis on the causal beliefs scale. Test–retest reliability, internal consistency and construct validity were also examined.

Results: The proposed eight-factor structure showed acceptable model fit, with high loadings and good reliability for all subscales. Correlations between subscales were consistent with theory and previous research.

Conclusions: The IPQ-BCS is valid and reliable, and provides unique understanding of specific perceptions held by this population, including beliefs surrounding risk of recurrence and consequences of ongoing hormonal treatment. Identifying these perceptions will aid development of interventions targeting depression, fear of recurrence and medication non-adherence.     

The impact of left and right intracranial tumors on picture and word recognition memory

This study investigated the effects of left and right intracranial tumors on picture and word recognition memory. We hypothesized that left hemispheric (LH) patients would exhibit greater word recognition memory impairment than right hemispheric (RH) patients, with no significant hemispheric group picture recognition memory differences. The LH patient group obtained a significantly slower mean picture recognition reaction time than the RH group. The LH group had a higher proportion of tumors extending into the temporal lobes, possibly accounting for their greater pictorial processing impairments. Dual coding and enhanced visual imagery may have contributed to the patient groups' similar performance on the remainder of the measures.     

Ethnic/racial differences in the coming-out process of lesbian, gay, and bisexual youths: a comparison of sexual identity development over time

This longitudinal report of 145 lesbian, gay, and bisexual (LGB) youths examined ethnic/racial differences in the coming-out process. No significant differences emerged in sexual developmental milestones, sexual orientation, sexual behavior, or sexual identity. However, Black youths reported involvement in fewer gay-related social activities, reported less comfort with others knowing their sexual identity, and disclosed that identity to fewer people than did White youths. Latino youths disclosed to fewer people than did White youths. Analyses of change indicated Black youths had greater increases in positive attitudes toward homosexuality and in certainty in their sexual identity over time than did White youths. These findings support the authors' hypothesis that cultural factors do not impede the formation of identity but may delay identity integration.