Examining neurochemical determinants of inspection time: Development of a biological model

Inspection time (IT), an information-processing correlate of psychometric intelligence, has been extensively studied. Previous research has shown that IT is a reliable correlate of psychometric intelligence across different developmental periods, mirroring developmental trends of fluid intelligence. Despite this extensive previous literature, very little is known about the biological basis of IT. In the present review, we discuss recent results from our laboratories examining the neurochemical determinants of IT. In this review, we outline the significance of several studies in which performance on the IT task is measured before and after modulating key human central nervous system (CNS) neurotransmitters and receptor systems (e.g., cholinergic, serotonergic, noradrenergic, and dopaminergic systems). The results of these studies indicate a primarily cholinergic basis for IT, although other aspects of psychometric intelligence may have serotonergic and dopaminergic determinants in addition to a cholinergic basis. The results are consistent with data reporting cholinergic depletion and impaired IT performance in dementia of the Alzheimer's type (DAT). Speculatively, we propose that compounds that enhance the release of the neurotransmitter acetylcholine (Ach) will improve IT and the variance that IT shares with IQ test performance.     

Thin-Ideal Internalization: Mounting Evidence for a New Risk Factor for Body-Image Disturbance and Eating Pathology

Body-image disturbance and eating disorders are a significant physical and mental health problem in Western countries. We describe emerging work on one newly identified variable that appears to be a potent risk factor for the development of these problems internalization of societal standards of attractiveness. Work conducted independently in our labs over the past decade has included scale development, correlational studies, prospective risk-factor studies, randomized experiments, and randomized prevention trials. Findings collectively suggest that internalization is a causal risk factor for body-image and eating disturbances, and that it appears to operate in conjunction with other established risk factors for these outcomes, including dieting and negative affect. Future research is needed to examine the specific familial, peer, and media influences that promote internalization and to replicate and extend our prospective and experimental studies.     

Confirmation in Couples' Communication About Weight Management: An Analysis of How Both Partners Contribute to Individuals' Health Behaviors and Conversational Outcomes

Using confirmation theory, this study investigated how romantic couples' (N = 100) accepting and challenging communication was associated with several weight management (WM) outcomes (i.e., partners' general effectiveness in motivating each other to enact healthy behaviors, productivity of WM conversations, and diet and exercise behaviors). Actor–partner interdependence model analyses showed that acceptance and challenge from partners simultaneously predicted how effective partners were in motivating healthy behaviors, but these components of confirmation predicted the other outcomes in different ways. Analyses across the outcomes also revealed that similar partner communication styles predicted general effectiveness, more productive WM conversations, and healthier eating habits. The findings of this study highlight the importance of assessing the interdependence of partners' WM efforts.     

Evaluation and integration of speech and pointing gestures during referential understanding

Two experiments investigated the relative influence of speech and pointing gesture information in the interpretation of referential acts. Children averaging 3 and 5 years of age and adults viewed a videotape containing the independent manipulation of speech and gestural forms of reference. A man instructed the subjects to choose a ball or a doll by vocally labeling the referent and/or pointing to it. A synthetic speech continuum between two alternatives was crossed with the pointing gesture in a factorial design. Based on research in other domains, it was predicted that all age groups would utilize gestural information, although both speech and gestures were predicted to influence children less than adults. The main effects and interactions of speech and gesture in combination with quantitative models of performance showed the following similarities in information processing between preschoolers and adults: (1) referential evaluation of gestures occurs independently of the evaluation of linguistic reference; (2) speech and gesture are continuous, rather than discrete, sources of information; (3) 5-year-olds and adults combine the two types of information in such a way that the least ambiguous source has the most impact on the judgment. Greater discriminability of both speech and gesture information for adults compared to preschoolers indicated small quantitative progressions with development in the ability to extract and utilize referential signals.     

Early and late SEPs—The later the potential the greater the relevance to personality

Short (N₂₁−P₂₇) and long (N₁₃₀−P₂₀₀) latency somatosensory evoked potentials (SEPs) and personality [Eysenck Personality Questionnaire (EPQ) and a short-form Sensation Seeking scale (SS)] were investigated in 26 young healthy adults. Various modes of analysis were carried out on the SEPs, including peak-to-peak, root mean square, absolute area and perimeter measures, over various time windows. The amount of SEP variance accounted for by personality correlations depended on the mode of analysis. High Psychoticism and high Sensation Seeking (and to some extent high Extraversion) correlated negatively with measures of SEP amplitude, the relationship being stronger for later SEP components.     

Predictors of Intention to Take Precautions Against AIDS Among Black College Students1

This research explored the relationship between behavioral intentions to engage in AIDS-risky sexual practices and a variety of variables that are theoretically and/or popularly assumed to be important factors in AIDS prevention. These variables included beliefs and knowledge about AIDS, fear of AIDS, perceived vulnerability of self and others, as well as probability that self and others on one's campus would contract AIDS, perceived efficacy to control exposure to AIDS, self-esteem, general locus of control, and past behavioral reaction to the threat of AIDS. General intention to “do something to protect oneself against AIDS,” and specific behavioral intention to use condoms in vaginal sex were measured and considered as possible proxies for future behavior. Data were collected from 124 black respondents in a southeastern university. In a series of multiple regression analyses, each of these measures of behavioral intentions was “predicted” from the other variables. Results showed that situational efficacy (to protect oneself from AIDS) was the best predictor of general intention, followed by reports of past behavioral changes as a result of the AIDS epidemic, and by knowledge. Proximal fear of AIDS was a negative predictor. For specific intentions, a specific belief about inconvenience in condom use was the best predictor, followed by past behavioral change, followed by knowledge. Normative beliefs, a belief that condoms would prevent disease, and distant threat of AIDS were also significant predictors. Theoretical and policy implications of the findings are discussed.     

A perceptual investigation of polytonality

Summary Four experiments investigated the perception of tonal structure in polytonal music. The experiments used musical excerpts in which the upper stave of the music suggested a different key than the lower stave. In Experiment 1, listeners rated the goodness of fit of probe tones following an excerpt from Dubois's Circus. Results suggested that listeners were sensitive to two keys, and weighted them according to their perceived importance within the excerpt. Experiment 2 confirmed that music within each stave reliably conveyed key structure on its own. In Experiment 3, listeners rated probe tones following an excerpt from Milhaud's Sonata No. 1 for Piano, in which different keys were conveyed in widely separate pitch registers. Ratings were collected across three octaves. Listeners did not associate each key with a specific register. Rather, ratings for all three octave registers reflected only the key associated with the upper stave. Experiment 4 confirmed that the music within each stave reliably conveyed key structure on its own. It is suggested that when one key predominates in a polytonal context, other keys may not contribute to the overall perceived tonal structure. The influence of long-term knowledge and immediate context on the perception of tonal structure in polytonal music is discussed.