Rate-decreasing effects of the atypical neuroleptic risperidone attenuated by conditions of reinforcement in a woman with mental retardation

Effects of two doses of risperidone on the performance of a matching task under tangible reinforcement and nonreinforcement conditions were measured in a woman with mental retardation. In both conditions, time to complete the task increased and response rates decreased under two doses of risperidone. Accuracy was generally unchanged. These changes were much smaller in the tangible reinforcement condition; thus, reinforcement seemed to protect performance from the rate-decreasing effects of risperidone.     

靶子的潜在位置数对辨别任务中返回抑制的影响

摘要在严格控制的条件下,以大学生为被试．采用线索一靶子模式的返回抑制范式．考察了靶子在注视点周边可能出现的位置数与辨别任务中返回抑制的关系。实验结果表明．在辨别任务中靶子的潜在位置数对返回抑制量有影响,随着位置数的增加,返回抑制量减小。该结论为返回抑制的注意性观点提供了新的证据。     

Event-related potentials in adolescents with combined ADHD and CD disorder: a single stimulus paradigm

Some studies of the event-related potentials demonstrated a reduction of the voluntary component P3 (P300 or P3b) in youngsters with the attention deficit/hyperactivity disorder (ADHD) or in conduct disorders (CD), and a reduction of the automatic processing component, mismatch negativity, in patients with both ADHD and CD (ADHD+CD). Recently, a passive auditory P3 potential has been elicited by a single stimulus. We therefore tried this potential study in 20 healthy subjects and 20 teenagers with ADHD+CD to search for further evidence of the altered automatic cerebral processing in the latter. Subjects also answered a self-report Dimensional Assessment of Personality Pathology (DAPP). The patient group scored significantly higher on most DAPP traits that reflect problems of emotion control, showed significantly prolonged P2, N2, and P3, and reduced P3. In all subjects Stimulus Seeking was positively correlated with P3 latencies at Fz, Cz, and Pz, and with P3 amplitude at Cz. This study suggests that youngsters with ADHD+CD had pronounced emotion dysregulation, and prominent deficit in passive attention, as reflected by the automatic processing of auditory stimuli.     

Practice effects on motor control in healthy seniors and patients with mild cognitive impairment and Alzheimer's disease

This research was designed to test the hypothesis that motor practice can enhance the capabilities of motor control in healthy controls (NC) and patients with a diagnosis of probable Alzheimer's disease (AD) and mild cognitive impairment (MCI), and consequently results in better motor performance. Approximately half of the subjects in the NC (n = 31), AD (n = 28), and MCI (n = 29) either received or did not receive practice on a task of fast and accurate arm movement with a digitizer. Changes in movement time (MT), movement smoothness (jerk), and percentage of primary submovement (PPS) were recorded and compared among the three groups across six blocks of trials (baseline and five training sessions). For all subjects, practice improved motor functions as reflected by faster and smoother motor execution, as well as a greater proportion of programming control. Compared to unaffected matched controls, AD and MCI subjects exhibited a greater reduction in movement jerk due to practice. Movement time and PPS data revealed that motor practice appeared to reduce the use of "on-line" correction adopted by the AD or MCI patients while performing the aiming movements. Evidently, their arm movements were quicker, smoother, and temporally more consistent than their untrained peers. The findings of this study shed light on how MCI and AD may affect motor control mechanisms, and suggest possible therapeutic interventions aimed at improving motor functioning in these impaired individuals.     

Studying suicide with psychological autopsy: social and cultural feasibilities of the methodology in China

As China opens its door to the world, suicide research is making rapid progress using methods and instruments developed in the West. This is a feasibility study of the psychological autopsy methodology applied in China, with its emphasis on the social and cultural environments. With samples of 66 completed suicides and 66 community normal living controls, the authors found that it is feasible to interview at least two informants for each suicide case and each control, between 2 and 6 months after the suicide. With the Chinese-cultivated contacting method of recruiting cases, the refusal rate is nearly zero. The Western-developed methodology per se proved to be valid in the Chinese culture. Ethical considerations in the context of Chinese culture are as important as in the West. Psychological autopsy technique is shown to be an equally applicable method for the study of completed suicides in Chinese culture as it is in the West. Future epidemiological research on Chinese suicide should use the psychological autopsy method to collect data from larger samples in order to increase our understanding of the risk factors for Chinese suicides.     

The heritability of attitudes: a study of twins.

The genetic basis of individual differences in attitudes was examined in a survey of 195 pairs of monozygotic twins and 141 pairs of same-sex dizygotic twins. A principal components analysis of the 30 attitude items in the survey identified 9 attitude factors, of which 6 yielded significant heritability coefficients. Nonshared environmental factors accounted for the most variance in the attitude factors. Possible mediators of attitude heritability were also assessed, including personality traits, physical characteristics, and academic achievement. Analyses showed that several of these possible mediators correlated at a genetic level with the heritable attitude factors, suggesting that the heritability of the mediator variables might account for part of the heritable components of some attitudes. There was also some evidence that highly heritable attitudes were psychologically "stronger" than less heritable attitudes.     

Heritability of personality disorders in childhood: a preliminary investigation

The heritability of personality disorder features was investigated in 112 child (ages 4-15 years) twin pairs (70 monozygotic and 42 dizygotic pairs). Parents assessed personality disorder features using the Coolidge Personality and Neuropsychological Inventory for Children (CPNI; Coolidge, 1998) that measures 12 personality disorders according to the criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) (American Psychiatric Association, 1994). Structural equation model-fitting methods indicated that the median heritability coefficient for the 12 scales was .75 (ranging from .81 for the Dependent and Schizotypal Personality Disorder scales to .50 for the Paranoid and Passive-Aggressive Personality Disorder scales). These results suggest that childhood personality disorders have a substantial genetic component and that they are similar to heritability estimates of personality disorder traits in adults and counter hypotheses that only temperaments and higher-order personality disorder traits have significant genetic components (Paris, 1997).     

Religious Involvement and Dynamics of Marijuana Use: Initiation,Persistence, and Desistence

Studies that examine the effects of adolescent religiosity on the initiation of, persistence in, and desistence from delinquency are rare. Yet, religion may differentially affect dimensions of delinquency in the early life course. Therefore, using data from the National Longitudinal Study of Adolescent Health (Add Health), we examine the relationship between measures of adolescent religion, as well as changes in religious involvement, and later patterns of marijuana use. We also examine the extent to which religious effects, if any, are mediated by key predictors of delinquency drawn from prominent criminological theories. The results suggest that the primary effect of religion on marijuana use is to prevent its initiation in the first place. Only part of religion's preventative effect on initiation is mediated by social bonds, delinquent peers, or self control. Although religious youth are less likely to ever use marijuana, adolescent religious involvement does not significantly predict desistence from marijuana use.