Brain imaging in neurogenetic conditions: realizing the potential of behavioral neurogenetics research

Behavioral neurogenetics research is a new method of scientific inquiry that focuses on investigation of neurodevelopmental dysfunction associated with specific genetic conditions. This research method provides a powerful tool for scientific inquiry into human gene-brain-behavior linkages that complements more traditional research approaches. In particular, the use of specific genetic conditions as models of common behavioral and cognitive disorders occurring in the general population can reveal insights into neurodevelopmental pathways that might otherwise be obscured or diluted when investigating more heterogeneous, behaviorally defined subject groups. In this paper, we review five genetic conditions that commonly give rise to identifiable neurodevelopmental and neuropsychiatric disability in children: fragile X syndrome, velo-cardio-facial syndrome, Williams syndrome, Turner syndrome, and Klinefelter syndrome. While emphasis is placed on describing the brain morphology associated with these conditions as revealed by neuroimaging studies, we also include information pertaining to molecular genetic, postmortem, and neurobehavioral investigations to illustrate how behavioral neurogenetics research can contribute to an improved understanding of brain disorders in childhood.     

Why people underestimate y when extrapolating in linear functions

E. L. DeLosh, J. R. Busemeyer, and M. A. McDaniel (1997) found that when learning a positive, linear relationship between a continuous predictor (x) and a continuous criterion (y), trainees tend to underestimate y on items that ask the trainee to extrapolate. In 3 experiments, the authors examined the phenomenon and found that the tendency to underestimate y is reliable only in the so-called lower extrapolation region--that is, new values of x that lie between zero and the edge of the training region. Existing models of function learning, such as the extrapolation-association model (DeLosh et al., 1997) and the population of linear experts model (M. L. Kalish, S. Lewandowsky, & J. Kruschke, 2004), cannot account for these results. The authors show that with minor changes, both models can predict the correct pattern of results.     

Measurement of alcohol-related consequences among high school and college students: application of item response models to the Rutgers Alcohol Problem Index

The Rutgers Alcohol Problem Index (RAPI; H. R. White & E. W. Labouvie, 1989) is a frequently used measure of alcohol-related consequences in adolescents and college students, but psychometric evaluations of the RAPI are limited and it has not been validated with college students. This study used item response theory (IRT) to examine the RAPI on students (N = 895; 65% female, 35% male) assessed in both high school and college. A series of 2-parameter IRT models were computed, examining differential item functioning across gender and time points. A reduced 18-item measure demonstrating strong clinical utility is proposed, with scores of 8 or greater implying greater need for treatment.     

Developing a biodata measure and situational judgment inventory as predictors of college student performance

This article describes the development and validation of a biographical data (biodata) measure and situational judgment inventory (SJI) as useful predictors of broadly defined college student performance outcomes. These measures provided incremental validity when considered in combination with standardized college-entrance tests (i.e., SAT/ACT) and a measure of Big Five personality constructs. Racial subgroup mean differences were much smaller on the biodata and SJI measures than on the standardized tests and college grade point average. Female students tended to outperform male students on most predictors and outcomes with the exception of the SAT/ACT. The biodata and SJI measures show promise for student development contexts and for selecting students on a wide range of outcomes with reduced adverse impact.     

Effects of objective and subjective account components on forgiving

The authors explored the effects of the components of a harm-doer's account of her transgression on the victims' emotional reactions to the transgression and to the character traits that she attributes to the harm-doer. Participants were 480 people whom the authors asked to imagine an incident in which they were harmed by the careless behavior of a friend. Subsequently, the authors offered participants an account of the harm-doer. In a 2 x 2 x 2 x 2 x 2 between-subjects design, the authors manipulated 5 account components: Admitting Fault, Admitting Damage, Expressing Remorse, Asking for Pardon, and Offering Compensation. The authors measured the participants' perceptions of these components. Results indicated that (a) the subjective perception of account components occurs schematically so that components are implicitly perceived without being objectively present, (b) objective components affect victims' reactions via subjective perceptions of these components, (c) personality factors (Irreconcilability, Interpersonal Trust, and Trait Anger) affect victims' reactions directly. Finally, certain configurations of account components are more effective than others. Specifically, asking for pardon had an effect on forgiving only when it was combined with an acknowledgment of the damage and a compensation offer. This result suggests that in this situation, the victim perceives a harm-doer's asking for pardon without the other components as an insincere apology.     

Inequality as ingroup privilege or outgroup disadvantage: the impact of group focus on collective guilt and interracial attitudes

Among members of privileged groups, social inequality is often thought of in terms of the disadvantages associated with outgroup membership. Yet inequality also can be validly framed in terms of ingroup privilege. These different framings have important psychological and social implications. In Experiment 1 (N = 110), White American participants assessed 24 statements about racial inequality framed as either White privileges or Black disadvantages. In Experiment 2 (N = 122), White participants generated examples of White privileges or Black disadvantages. In both experiments, a White privilege framing resulted in greater collective guilt and lower racism compared to a Black disadvantage framing. Collective guilt mediated the manipulation's effect on racism. In addition, in Experiment 2, a White privilege framing decreased White racial identification compared to a Black disadvantage framing. These findings suggest that representing inequality in terms of outgroup disadvantage allows privileged group members to avoid the negative psychological implications of inequality and supports prejudicial attitudes.     

Exploring age differences in the stress-buffering function of social support

The purpose of this study is to see if there are age differences in the relationship between chronic financial strain, emotional support, and life satisfaction among people aged 65 and older. Data from a nationwide survey of older people (N = 1,518) indicate that emotional support tends to reduce the noxious effects of economic problems on life satisfaction for the sample as a whole. However, the findings further reveal that the potential benefits of emotional support arise primarily among the oldest-old. In contrast, emotional support does not offset the negative effects of financial strain on life satisfaction among the young-old.     

Emotional Responses to APO E Genotype Disclosure for Alzheimer Disease

The purpose of our study is to assess the emotional responses to disclosing APO E genotype to asymptomatic older adults at increased risk for Alzheimer disease (AD). This is a longitudinal cohort study of volunteer subjects who were aged 50 years or over, asymptomatic for (AD), had a family history of AD, passed a psychological assessment, and participated in pre- and post-test genetic counseling and three follow-up visits over 10 months. We analyzed responses by three emotional constructs: depressed, worried, and relieved. Three hundred and twenty-eight subjects were screened, 76 received their APO E genotype. When emotional responses occurred it was immediate, between baseline and the 1 month follow-up. Emotional reactions did not change significantly past 1 month. Our results suggest that for emotionally stable persons, disclosing results of their APO E genotype, high risk subjects did not report more depression or worry and low risk subjects felt relieved by knowing the results. Future studies should evaluate the risks of disclosure to family members involved in the diagnostic work-up of a relative and include subjects from a broader range of emotional stability and socioeconomic background.     

Assessment of infant cry: acoustic cry analysis and parental perception

Infant crying signals distress to potential caretakers who can alleviate the aversive conditions that gave rise to the cry. The cry signal results from coordination among several brain regions that control respiration and vocal cord vibration from which the cry sounds are produced. Previous work has shown a relationship between acoustic characteristics of the cry and diagnoses related to neurological damage, SIDS, prematurity, medical conditions, and substance exposure during pregnancy. Thus, assessment of infant cry provides a window into the neurological and medical status of the infant. Assessment of infant cry is brief and noninvasive and requires recording equipment and a standardized stimulus to elicit a pain cry. The typical protocol involves 30 seconds of crying from a single application of the stimulus. The recorded cry is submitted to an automated computer analysis system that digitizes the cry and either presents a digital spectrogram of the cry or calculates measures of cry characteristics. The most common interpretation of cry measures is based on deviations from typical cry characteristics. Another approach evaluates the pattern across cry characteristics suggesting arousal or under-arousal or difficult temperament. Infants with abnormal cries should be referred for a full neurological evaluation. The second function of crying--to elicit caretaking--involves parent perception of the infant's needs. Typically, parents are sensitive to deviations in cry characteristics, but their perception can be altered by factors in themselves (e.g., depression) or in the context (e.g., culture). The potential for cry assessment is largely untapped. Infant crying and parental response is the first language of the new dyadic relationship. Deviations in the signal and/or misunderstanding the message can compromise infant care, parental effectiveness, and undermine the budding relationship. (c) 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:83-93.