Memory deficits in Alzheimer's disease: the encoding hypothesis and cholinergic function

Forgetting functions generated by delayed matching-to-sample procedures allow delay-dependent effects to be distinguished from delay-independent effects on working memory. Parameters of negative exponential functions estimate initial discriminability (intercept) and rate of forgetting (slope). Forgetting functions for patients with Alzheimer's disease indicate that they differ from normal controls in terms of reduced initial discriminability—that is, in the encoding component of memory performance— but not convincingly in rate of forgetting. Reanalyses of previous studies with different species suggest that pro- and anticholinergic drugs influence initial discriminability in delayed matching-to-sample performance, but not rate of forgetting. The results of our reanalyses are consistent with the conclusion that the cholinergic system plays a role in the encoding component of working memory and that this is the main characteristic of the memory deficit shown by patients with Alzheimer's disease.     

Neurophysiological markers of early language acquisition: from syllables to sentences

Recently, there have been several reports of the neurophysiological correlates of language acquisition. These indicate that the infant's brain is able to discriminate different phonemes within the first 2 months of life, that knowledge about stress patterns and phonotactic rules is established between 5-12 months, and that phonotactic knowledge begins to interact with lexical-semantic processes between 12-14 months. Electrophysiological markers for lexical-semantic processes indicate that semantic processing of words in picture contexts is present at 14 months and for words in sentential contexts around 30 months. At 32 months, children demonstrate an adult-like electrophysiological response pattern to syntactic violations. The similarities between the brain response patterns observed in children and adults support the view that language develops in a continuous manner.     

Why do some men misperceive women's sexual intentions more frequently than others do? An application of the confluence model

Although many researchers have documented men's tendency to misperceive women's friendliness as a sign of sexual interest, few have examined individual differences in men's attitudes and past experiences that might predict their likelihood of making these types of misjudgments. We applied an expanded version of Malamuth, Sockloskie, Koss, and Tanaka's (1991) Confluence model to predict frequency of misperception of women's sexual intent with a sample of 356 male college students. Using structural equation modeling, hostile masculinity, impersonal sex, and drinking in dating and sexual situations predicted men's frequency of misperception. Furthermore, the more risk factors men possessed, the more times they misperceived women's sexual intentions. Suggestions are made for theory development and future research incorporating situational as well as personality measures in longitudinal studies.     

Career Research Interests and Training of Genetic Counseling Students

Research is important to validate clinical services, provide information on the effectiveness of practice techniques, and develop the knowledge base of a clinical profession. Genetic counseling students from American Board of Genetic Counseling (ABGC) accredited training programs were surveyed to determine their career research interests and interest in pursuing a hypothetical doctoral degree in genetic counseling. Genetic counseling program directors were surveyed to assess the emphasis on research training within their programs. A substantial number (46%, n = 92) of genetic counseling students are interested in performing research in their careers and many (40%, n = 80) would pursue a doctoral degree in genetic counseling if it was available. Students and directors from programs with a thesis requirement reported a significantly higher emphasis on career research preparation than those from programs without a thesis requirement. The results of this study indicate that future genetic counselors are interested in contributing to the research base that will advance the field. This study suggests a need to strengthen research training within ABGC accredited graduate programs and explore the development of a doctoral degree option in genetic counseling.     

Family Emotional Climate and Sibling Relationship Quality: Influences on Behavioral Problems and Adaptation in Preschool-Aged Children

We examined the impact of family emotional climate and sibling relationship quality on behavioral problems and adaptation in preschool-aged children. Participants were 63 mothers with a preschool-aged child enrolled in a Southern Arizona Head Start Program. Siblings were identified as children closest in age to target child. Mothers of predominantly Mexican descent (95%) participated in home interviews during the Fall and Spring of the year children entered center-based programs. Sibling relationship quality (warmth, agonism/competition) was proposed to predict children’s adjustment (behavioral problems and adaptation) longitudinally. Results indicate that after controlling for child characteristics (temperament, child gender, birth order) and after accounting for family characteristics (family emotional expressiveness, child exposure to interparental conflict, and parental agreement on childrearing), sibling warmth made a significant and unique contribution to child adjustment as reported by mothers and teachers six months later. Findings are consistent with existing research indicating that sibling relationships impact children’s adjustment and shape young children’s lives in meaningful and marked ways. Moreover, these associations were found with an understudied sample of young children of predominantly Mexican descent in low-income families, and thus make an important contribution to knowledge in the field.     

Behavioral Activation as an Early Intervention for Posttraumatic Stress Disorder and Depression Among Physically Injured Trauma Survivors

This paper describes an adaptation of behavioral activation (BA) for the early intervention of posttraumatic stress disorder (PTSD) and depression among physically injured survivors of traumatic injury, and presents pilot data on a small randomized effectiveness trial (N = 8). The application of BA to PTSD is based on the theory that increases in guided activity may break patterns of avoidance that can maintain PTSD. Compared to treatment as usual (TAU), those who received BA showed improvement in PTSD symptom severity from pre- to posttreatment, and there was a trend for the BA group to score better than the TAU group on physical functioning. Contrary to expectation, this brief adaptation did not have an impact on depression. Implications of these results for the effective early intervention after trauma are discussed.     

Visual attention as a predictor of on-road driving performance of older drivers

With increasing numbers of older drivers on Australian roads, it is important to determine the functional abilities most closely related to driving ability among older adults. To this end, 90 drivers aged from 60 to 91 completed a battery of psychological, visual, physical and cognitive tests, and a standardised on-road driving test. A computerised test of visual attention, devised specifically for the study, was the best predictor of on-road driving performance. Other abilities that made independent contributions to the prediction of driving performance were contrast sensitivity and visuospatial memory. These functional abilities provided a better prediction of driving performance than chronological age, reinforcing the argument that drivers should only have their driving tested when their functional abilities decline, rather than when they reach a particular age.     

The development of in-group favoritism: between social reality and group identity

This study examined how social reality restricts children's tendency for in-group favoritism in group evaluations. Children were faced with social reality considerations and with group identity concerns. Using short stories, in this experimental study, conducted among 3 age groups (6-, 8-, and 10-year-olds), the authors examined the trait attribution effects of reality constraints on eye-color differences and national group differences. The results show that the trait attributions of all age groups were restricted by the acceptance of socially defined reality. In addition, when the information about reality was not considered accurate, only the youngest children showed positive in-group favoritism. It is argued that these findings are useful in trying to reconcile some of the divergent and contrasting findings in the developmental literature on children's intergroup perceptions and evaluations.     

The development of expert face processing: are infants sensitive to normal differences in second-order relational information?

Sensitivity to second-order relational information (i.e., spatial relations among features such as the distance between eyes) is a vital part of achieving expertise with face processing. Prior research is unclear on whether infants are sensitive to second-order differences seen in typical human populations. In the current experiments, we examined whether infants are sensitive to changes in the space between the eyes and between the nose and the mouth that are within the normal range of variability in Caucasian female faces. In Experiment 1, 7-month-olds detected these changes in second-order relational information. Experiment 2 extended this finding to 5-month-olds and also found that infants detect second-order relations in upright faces but not in inverted faces, thereby exhibiting an inversion effect that has been considered to be a hallmark of second-order relational processing during adulthood. These results suggest that infants as young as 5 months are sensitive to second-order relational changes that are within the normal range of human variability. They also indicate that at least rudimentary aspects of face processing expertise are available early in life.