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Biomedical subjects

D F Halpern

Publications and source records attributed to D F Halpern.

At least 19 recordsLinked to original sources
PubMed2001

Stereotypes and steroids: using a psychobiosocial model to understand cognitive sex differences.

To further our understanding of cognitive sex differences, we studied the relationship between menstrual phase (via serum estradiol and progesterone levels) and cognitive abilities and cognitive performance in a sample of medical students in eastern Turkey. As expected, we found no sex differences on the Cattell "Culture Fair Intelligence Test" (a figural reasoning test), with females scoring significantly higher on a Turkish version of the Finding A's Test (rapid word knowledge) and males scoring significantly higher on a paper-and-pencil mental rotation test. The women showed a slight enhancement on the Finding A's Test and a slight decrement in Cattell scores during the preovulatory phase of their cycle that (probably) coincided with a rise in estrogen. There were also small cycle-related enhancements in performance for these women on the mental rotation test that may reflect cyclical increases in estrogen and progesterone. Additional analyses showed an inverted U-shaped function in level of estradiol and the Cattell Test. Finally, for women who were tested on Day 10 of their menstrual cycle, there was a negative linear relationship between their Cattell scores and level of progesterone. Stereotypes about the cognitive abilities of males and females did not correspond to performance on the mental rotation or Finding A's Test, so the sex-typical results could not be attributed to either stereotype threat or stereotype activation. For practical purposes, hormone-related effects were generally small. Variations over the menstrual cycle do not provide evidence for a "smarter" sex, but they do further our understanding of steroidal action on human cognitive performance.

Adolescent↗
PubMed1999

Sex differences in visuospatial working memory: components of cognitive processing.

Numerous studies have shown that sex differences in visuospatial tasks vary in size and direction depending on the nature of the task, with large differences favoring males on tasks that require transformations in visuospatial working memory. The cognitive processes underlying these differences were investigated using laboratory tasks developed by Dror and Kosslyn (1994). Four cognitive components of visuospatial working memory were assessed--image generation, maintenance, scanning, and transformation--in an attempt to identify the components that would show differential effects for females and males. The image generation task required retrieval of shape information from long-term memory, generation of a visual image in working memory, and utilization of the information about the shape in a decision task. The image maintenance task required only the latter two processes. The information processing demands required by scanning and rotation tasks came from the need to transform the visual image so that it could be used in decision making. Males responded more quickly on all four tasks (ds between .63 and .77), with no between-sex differences in accuracy. We concluded that speed of processing is central to understanding sex differences in visuospatial working memory. We discuss implications of these findings for performance on real-world visuospatial tasks.

Adult↗
PubMed1998

Handedness and sex differences in intelligence: evidence from the medical college admission test.

Our analysis of Medical College Admission Test subtest scores by writing hand preference and sex suggests that (a) right hemispheric dominance is associated with intellectual giftedness in verbal reasoning (left-handers obtained higher scores on the verbal reasoning test and were overrepresented in the upper tail of the distribution), (b) different patterns of brain lateralization are associated with different subcomponents of cognition (right-handers scored higher, on average, on the writing test and were overrepresented in the upper tail of the distribution), and (c) men generally score higher than women on tests of scientific knowledge (the most striking differences between men and women were on the biological and physical science tests).

Adult↗
PubMed1998

Teaching critical thinking for transfer across domains. Dispositions, skills, structure training, and metacognitive monitoring.

Advances in technology and changes in necessary workplace skills have made the ability to think critically more important than ever before, yet there is ample evidence that many adults consistently engage in flawed thinking. Numerous studies have shown that critical thinking, defined as the deliberate use of skills and strategies that increase the probability of a desirable outcome, can be learned in ways that promote transfer to novel contexts. A 4-part empirically based model is proposed to guide teaching and learning for critical thinking: (a) a dispositional component to prepare learners for effortful cognitive work, (b) instruction in the skills of critical thinking, (c) training in the structural aspects of problems and arguments to promote transcontextual transfer of critical-thinking skills, and (d) a metacognitive component that includes checking for accuracy and monitoring progress toward the goal.

Adult↗
PubMed1997

Sex differences in intelligence. Implications for education.

Sex differences in intelligence is among the most politically volatile topics in contemporary psychology. Although no single finding has unanimous support, conclusions from multiple studies suggest that females, on average, score higher on tasks that require rapid access to and use of phonological and semantic information in long-term memory, production and comprehension of complex prose, fine motor skills, and perceptual speed. Males, on average, score higher on tasks that require transformations in visual-spatial working memory, motor skills involved in aiming, spatiotemporal responding, and fluid reasoning, especially in abstract mathematical and scientific domains. Males, however, are also over-represented in the low-ability end of several distributions, including mental retardation, attention disorders, dyslexia, stuttering, and delayed speech. A psychobiosocial model that is based on the inextricable links between the biological bases of intelligence and environmental events is proposed as an alternative to nature-nurture dichotomies. Societal implications and applications to teaching and learning are suggested.

Adolescent↗
PubMed1994

Laterality, sexual orientation, and immune system functioning: is there a relationship?

There have been numerous recent investigations of the possibility that laterality (the extent to which an individual is right or left-sided or, more usually, right- or left-handed), sexual orientation (homosexual, bisexual, or heterosexual), and immune system functioning are related. The reasons for inconsistencies in the literature and failures to reject the null hypothesis are discussed. Additional data are presented that show a positive relationship between left-sided laterality and homosexuality for a sample of HIV positive males. Immune system disorders were not associated with any of the other variables. It is concluded that increased left-sidedness is more likely in homosexual men as a group, but laterality cannot be used to differentiate homosexual men further into categories that vary in their susceptibility to immune disorders.

Adolescent↗
PubMed1993

A replay of the baseball data.

Fudin, Renninger, Lembessis, and Hirshon (1993) reported a nonsignificant longevity advantage for right-handers in their analysis of archival baseball data, although the absolute values are still in the predicted direction. Differences in specific data entries and analyses are difficult to resolve; however, there is some indication that the data base that they analyzed differs from that in our study. Further, their use of parametric statistics, given distributional problems and grossly unequal group sizes, may account for the nonsignificance they observed, when compared to the nonparametric analyses that we used. While we considered our original study a pilot project, the literature now contains hundreds of studies that show that left-handedness is associated with a wide range of health-risk factors including serious accidents, immune system disorders, and birth-related complications that involve reduced oxygen. A recent study of the archival records of over 3000 cricket players showed a significant advantage of over 2 years in longevity for right-handed cricket players. On the basis of these findings, we still believe that left-handedness is a marker for reduced longevity.

Baseball↗
PubMed1991

Left-handedness: a marker for decreased survival fitness.

Life span studies have shown that the population percentage of left-handers diminishes steadily, so that they are drastically underrepresented in the oldest age groups. Data are reviewed that indicate that this population trend is due to the reduced longevity of left-handers. Some of the elevated risk for sinistrals is apparently due to environmental factors that elevate their accident susceptibility. Further evidence suggests that left-handedness may be a marker for birth stress related neuropathy, developmental delays and irregularities, and deficiencies in the immune system due to the intrauterine hormonal environment. Some statistical and physiological factors that may cause left-handedness to be selectively associated with earlier mortality are also presented.

Functional Laterality↗
PubMed1985

Magazine versus physicians: the influence of information source on intentions to use oral contraceptives.

College students read either pro or con passages about oral contraceptives. All passages contained the same statistical information, differing only in the way the information was interpreted. The passages were attributed either to a traditional physician, nontraditional physician, traditional magazine, or nontraditional magazine. Subjects in the pro condition were more favorable towards oral contraceptive use and subjects in the con condition were more opposed to oral contraceptive use than they were before reading the stimulus materials, thus suggesting that the same statistical information can be used persuasively to argue either for or against oral contraceptives. Males were significantly more likely to change their attitudes towards oral contraceptives than females.

Adolescent↗
PubMed1984

Age differences in response time to verbal and symbolic traffic signs.

It is well established that verbal skills are maintained at a high level into old age while visuo-spatial skills begin to decline at an earlier age. it was hypothesized that the elderly would therefore respond more quickly to verbal traffic signs than to symbolic ones. In a test of this hypothesis, response times (RT's) to symbolic and verbal traffic signs were obtained from subjects in two age groups (19-29 and 65-77 years). While the elderly responded more slowly than the young subjects, they were an average of .2 seconds quicker in response to verbal traffic signs than symbolic ones. There were no differences in RT for symbolic and verbal signs for the young subjects. It is clear that the impact of traffic signs changes on the elderly deserves more attention than it is currently being given.

Adult↗
PubMed1983

The multiple determination of illusory contours: 1. A review.

Four theories of illusory-contour perception are reviewed--brightness contrast (simultaneous contrast, assimilation, and dissimilation), depth/completion, partial activation of neural feature analyzers, and the diffuse-sharp dichotomy. It is concluded that the processes and mechanisms involved in illusory-contour perception most likely depend upon the stimulus elements used in the illusory-contour display.

Discrimination Learning↗
PubMed1983

The multiple determination of illusory contours: 2. An empirical investigation.

Judgments of contour strength or saliency for twenty-four illusory-contour configurations were subjected to a confirmatory factor analysis. A four-factor model that posited the involvement of simultaneous contrast, linear effects (assimilation and dissimilation), depth/completion cues, and feature analyzers accounted for a substantial proportion of the variance in judgments of illusory-contour strength. The hierarchical addition of a fifth factor, diffuse illusory contours, significantly improved the overall fit of the model, but added little to the proportion of explained variance. The taxonomic approach adopted provides support for a multiprocess model of illusory-contour perception.

Adolescent↗