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Biomedical subjects

R H Pollack

Publications and source records attributed to R H Pollack.

At least 19 recordsLinked to original sources

Do changes in the stereotypic depiction of a lesbian couple affect heterosexuals' attitudes toward lesbianism?

This study tested the hypothesis that heterosexuals with traditional sex role values would be less negative toward lesbians after reading a nonstereotypical description of a lesbian couple as opposed to a stereotypical description. Two experiments were conducted to assess stereotypes of lesbian couples and to test the hypothesis. Consistent with the hypothesis, traditional males showed significantly more positive attitudes toward lesbians as a result of exposure to less stereotypical depictions of couples. For nontraditional males treatments were ineffective, as expected. Counter to the hypothesis, exposure to nonstereotypical depictions of lesbian couples had no significant effect on traditional or nontraditional females' attitudes toward lesbians.

Adolescent↗

Factors predicting high-risk sexual behavior in heterosexual college females.

The purpose of this study was to determine which factors based in social cognitive theory are associated with risky sexual behavior in heterosexual college females. Results showed that negative attitudes toward condoms and toward involvement in a relationship were associated with less consistent condom use; frequent alcohol use preceding intercourse and low sexual satisfaction were associated with less consistent contraceptive use. Sex education on the college campus currently provides protection information only; these strategies have not proved successful. We encourage the development of more comprehensive educational strategies, which include discussion of the social cognitive factors shown here to be associated with risky sexual behavior.

Adult↗

The effect of lightness contrast on the colored Müller-Lyer illusion.

Two subjects estimated the length of the central line in red and blue Müller-Lyer figures that were viewed both foveally and parafoveally. The illusion figures were defined by either lightness and hue differences between figure and ground or by a hue difference alone. For both subjects, the figures defined solely by hue produced larger illusions. Since depth-cue scaling and other cognitive factors did not cause the enlargement, it was concluded that the robust, hue-produced illusions resulted from contour interactions generated within parvocellular channels that are specialized for coding color.

Adult↗

Configuration color vision tests: the interaction between aging and the complexity of figure-ground segregation.

A cross-sectional study comparing response time and the percentage of items correctly identified in three color vision tests (Pflügertrident, HRR-AO pseudoisochromatic plates, and AO pseudoisochromatic plates) was carried out on 72 women (12 in each decade) ranging from ages 20 to 79 years. Overall, time scores increased across the age groups. Analysis of the correctness scores indicated that the AO pseudoisochromatic plates requiring the identification of numbers was more difficult than the other tests which consisted of geometric forms or the letter E. This differential difficulty increased as a function of age. There was no indication of color defect per se which led to the conclusion that figure complexity may be the key variable determining performance. The results were similar to those obtained by Lee and Pollack (1978) in their study of the Embedded Figures Test.

Adult↗

Age differences in dark-interval threshold across the life-span.

The threshold for the dark interval between two flashes was used to examine differences in stimulus persistence in 72 subjects aged 20 to 79 years. The data were then combined with results from two previous studies involving children and adolescents; thus, a cross sectional, adult, life-span view of differences in the dark-interval threshold was presented. Results showed that during childhood and adolescence there is a decline in stimulus persistence as a result of decreased receptor sensitivity. In adulthood, however, the dark-interval threshold remains fairly stable until the 70s where it increases significantly. Two possible explanations for this increase in stimulus persistence in old age are discussed.

Adult↗

Differences in the magnitude of the Delboeuf Illusion and Usnadze Effect during adulthood.

The Delboeuf illusion (Type I) and Usnadze Effect (Type II) were used to investigate changes in perceptual processes in 72 female subjects, aged 20-79 years. Unlike other studies, small figures (less than 2 degrees) were presented for brief periods under fixation conditions. The magnitude of the Delboeuf illusion increased in old age, while the magnitude of the Usnadze Effect showed no change.

Adult↗

The effects of age on perceptual problem-solving strategies.

Witkin's Embedded Figures Test (EFT) was used to measure the changes with age in field dependence and problem-solving ability Qualitative data concerning problem-solving strategies and quantitative data were collected. EFT was administered to 12 females in each of the following decades: 20s, 30s, 40s, 50s, 60, 70s. All subjects were moderately to well educated, healthy, and relatively active members of the community. All had at least 20/33 corrected or uncorrected vision. An interview was held with each participant after completion of the EFT. ANOVA of time scores indicated that significantly (p less than 0.01) more time is needed to solve the items with an increase in age; a Tukey (a) test revealed a significant (p less than 0.05) increase between the 40s and 60s age groups. With an increase in age a significant (p less than 0.01) decline in the number of items solved was found. Partial correlations revealed that age is the most important factor, vis-á-vis general intelligence, visual acuity, and the personality factors measured by the Eysenck Personality Inventory. The relative stability of performance up through 49 and after 50 implies a decline in field independence rather than in higher-order cognitive processes.

Adult↗

Problem-solving as a function of age, sex and the role appropriateness of the problem content.

The purpose of this study was to investigate problem-solving ability as a function of age, sex and problem content by using 20 problems chosen from the problem-solving literature. The problems were administered without time limits to 8 males and 8 females in each of three age groups: 20--30, 40--50, 60--70. Analysis revealed that only age influenced performance with the middle-age group scoring significantly higher than the other groups. Analysis of the time required by each age group to solve the problems showed the young group required significantly less time than the other groups. Finally, the young group was seen to make more errors of commission while the older group made more errors of omission.

Adult↗

Visual acuity for single lines as a function of hue and age.

176 students in grades 2-12 were tested for visual acuity as a function of minimally resolvable red, yellow, green, and blue lines. A 3-way mixed analysis of variance revealed significant differences among the colors, with better acuity for longer wavelengths. Significant age effects as well as a sex X condition interaction were also found. Post hoc analysis revealed a significant quartic trend for age. It is argued that the differential acuity thresholds for hue and the curvilinear age trend may depend upon the coordination of the accommodation and refractive power of the eye, which are affected by differential growth rates of the lens and the axial length of the eye.

Accommodation, Ocular↗

Mueller-Lyer illusion: effect of age, lightness contrast, and hue.

Mueller-Lyer figures produced by lightness contrast (white on black) and by hue contrast in the absence of lightness contrast (red, yellow, green, or blue on gray) were presented to subjects aged nine to adult. Contrary to Piagetian expectations, the illusion magnitudes resulting from the colored figures did not decline with age.

Adolescent↗