18 research outputs found
Visual Properties of Transgenic Rats Harboring the Channelrhodopsin-2 Gene Regulated by the Thy-1.2 Promoter
Channelrhodopsin-2 (ChR2), one of the archea-type rhodopsins from green algae, is a potentially useful optogenetic tool for restoring vision in patients with photoreceptor degeneration, such as retinitis pigmentosa. If the ChR2 gene is transferred to retinal ganglion cells (RGCs), which send visual information to the brain, the RGCs may be repurposed to act as photoreceptors. In this study, by using a transgenic rat expressing ChR2 specifically in the RGCs under the regulation of a Thy-1.2 promoter, we tested the possibility that direct photoactivation of RGCs could restore effective vision. Although the contrast sensitivities of the optomotor responses of transgenic rats were similar to those observed in the wild-type rats, they were enhanced for visual stimuli of low-spatial frequency after the degeneration of native photoreceptors. This result suggests that the visual signals derived from the ChR2-expressing RGCs were reinterpreted by the brain to form behavior-related vision
Mini-Mental State Examination: Greek Normative Data Stratified by Age and Education in a Large Sample of 925 Community-Dwelling Healthy Participants
Background: Cognitive screening measures are widely administered in everyday clinical practice in different geriatric settings. Despite the presence of several extended-like screening tests, Mini-Mental State Examination (MMSE) continues to be largely used not only by neuropsychologists, neurologists, and psychiatrists but also by general practitioners and other health-related specialties. Aim: We herein provide normative data for the MMSE in a large sample of community-dwelling healthy participants aged over 50 years old stratified by age and education. Material and Methods: The sample included 925 community-dwelling healthy participants (age range: 50â91 years) of both genders (231 males/694 females) with different educational level (range: 1â16 years). Demographic-related effects were examined for the total MMSE score using hierarchical regression analysis; normative data are presented in mean ± standard deviation and percentile ranks and divided into seven overlapping age tables with different midpoints at 55, 60, 65, 70, 75, 80, and 85 years using the overlapping cell procedure. Results: Initial analysis did not show any effect of gender but revealed significant correlation between age, education, and total MMSE. Hierarchical regression analysis revealed that education significantly accounted for 17.3% of the total variance in the MMSE with age adding a significant 7.4% to the final model (adjusted R2 = 0.246, F = 151.872, p < 0.001; age: ÎČ = â0.286, p < 0.001; education: ÎČ = 0.332, p < 0.001). The sample was stratified according to the overlapping cell procedure with regard to age (age groups: 50â60, 55â65, 60â70, 65â75, 70â80, 75â85, 80â91); four educational levels were considered: 1â5, 6â9, 10â12, and 13â16 years. Conclusions: Current normative data for the Greek version of the MMSE are provided as a useful set of norms for clinical and research practice. © Springer Nature Switzerland AG 2020
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The âBrady Bunchâ lineup: Comparing video and photographic simultaneous and sequential lineups
In recent years considerable empirical and legislative effort has been made to ensure that identification procedures by witnesses are both sensitive and fair. High sensitivity increases the likelihood of offender identification, whereas a fair method reduces the likelihood of an innocent suspect identification. In the UK, the preferred method of lineup presentation requires the witness to sequentially view the suspect and eight foils in 15-sec video clips. The entire sequence of videos is viewed twice. A first experiment was designed to examine whether viewing the second video âlapâ induces a response bias by comparing outcomes when the sequence was shown twice with those when it was shown once. A second experiment was designed to contribute to the debate in the literature as to the relative fairness and sensitivity of sequential and simultaneous lineups in which all members are displayed at the same time. This research has primarily employed photographs. However, videos should provide more identity cues than photographs and this issue was examined by comparing outcomes of simultaneous photo and sequential photo and video lineups, as well as what is believed to be the first empirical test of simultaneous video lineups. The theoretical implications are discussed in terms of best practice for real identification procedures