Time processing in children with Tourette’s syndrome

Background

Tourette syndrome (TS) is characterized by dysfunctional connectivity between prefrontal cortex and sub-cortical structures, and altered meso-cortical and/or meso-striatal dopamine release. Since time processing is also regulated by fronto-striatal circuits and modulated by dopaminergic transmission, we hypothesized that time processing is abnormal in TS.

Methods

We compared time processing abilities between nine children with TS-only (i.e. without major psychiatric comorbidities) and 10 age-matched healthy children, employing a time reproduction task in which subjects actively reproduce different temporal intervals, and a time comparison task in which subjects judge whether a test interval is longer or shorter than a reference interval. IQ, sustained and divided attention, and working memory were assessed in both groups using the Leiter International Performance Scale-Revised, and the Digit Span sub-test of the WISC-R.

Results

Children with TS-only reproduced in an overestimated fashion over-second, but not sub-second, time intervals. The precision of over-second intervals reproduction correlated with tic severity, in that the lower the tic severity, the closer the reproduction of over-second time intervals to their real duration. Time reproduction performance did not significantly correlate with IQ, attention and working memory measures in both groups. No differences between groups were documented in the time comparison task.

Conclusions

The improvement of time processing in children with TS-only seems specific for the over-second range of intervals, consistent with an enhancement in the ‘cognitively controlled’ timing system, which mainly processes longer duration intervals, and depends upon dysfunctional connectivity between the basal ganglia and the dorso-lateral prefrontal cortex. The absence of between-group differences on time comparison, moreover, suggests that TS patients manifest a selective improvement of ‘motor’ timing abilities, rather than of perceptual time abilities. Our data also support an enhancement of cognitive control processes in TS children, probably facilitated by effortful tic suppression.     

Spirituality and Religiousness Among American Jews

In this article we examine the association between spirituality and religiousness for Jews in the United States. Using data from the most recent National Jewish Population Survey of 2000–2001, a large national sample, we examined the extent to which these two concepts correlate. In addition, we compared the relative importance of sociodemographic factors, stressors, and Jewish contextual factors in predicting spirituality and religiousness. We found that spirituality and religiousness correlated, but modestly; some variables were predictive of both concepts (less education, younger age, experienced anti-Semitism in last year, ethnic identity, social identity), some of being highly spiritual only (female, not living in the Northeast), and others of being highly religious only (being married, having a child at home, living in the Northeast, not living in the West, and Jewish background). The differences in sociodemographic characteristics and Jewish background suggest that family life (marriage, having children at home), knowledge about Judaism, and living in a geographic area where there is a high population of Jews are conducive to religiousness as a framework for meaning. Jewish contextual factors were salient for both spiritual and religious pathways.     

Effect of the 5-HTTLPR polymorphism on posttraumatic stress disorder,depression, anxiety,and quality of life among Iraq and Afghanistan veterans

Background and Objectives: Posttraumatic stress disorder (PTSD), depression, anxiety, and stress are significant problems among returning veterans and are associated with reduced quality of life. Design: A correlational design was used to examine the impact of a polymorphism (5-HTTLPR) in the serotonin transporter promoter gene on post-deployment adjustment among returning veterans. Methods: A total of 186 returning Iraq and Afghanistan veterans were genotyped for the 5-HTTLPR polymorphism. Symptoms of PTSD, depression, general stress, and anxiety were assessed along with quality of life. Results: After controlling for combat exposure, age, sex of the participant, and race, 5-HTTLPR had a significant multivariate effect on post-deployment adjustment, such that S′ carriers reported more post-deployment adjustment problems and worse quality of life than veterans homozygous for the L′ allele. This effect was larger when the analyses were restricted to veterans of European ancestry. Conclusions: Our findings suggest that veterans who carry the S′ allele of the 5-HTTLPR polymorphism may be at increased risk for adjustment problems and reduced quality of life following deployments to war zones.     

Time course of planning for object and action parameters in visually guided manipulation

Under visual guidance, subjects reached for and manipulated an object that variedin weight and surface texture (slipperiness). The manipulatory action was either grasping, lifting, or posting in a slot. The task was constrained or unconstrained with respect to speed, grasp pattern, and contact force. Initiation time (pre-reach), movement time (reach), and post-contact errors were measured, to examine planning for task performance at three points in time. Results indicate that in the constrained task, the manipulatory action was planned during the initiation time, but planning for object parameters was deferred until the reach interval. With relaxed task constraints, initiation times increased,and texture and manipulatory action had independent effects on premovement planning. Errors were affected interactively by all variables. The results suggest a planning process that unfolds over time, incorporating in turn the manipulatory action, object texture, and object weight. This unfolding accommodates variables proximate to the time where they will affect physical action.     

Multilevel Mixture Factor Models

Factor analysis is a statistical method for describing the associations among sets of observed variables in terms of a small number of underlying continuous latent variables. Various authors have proposed multilevel extensions of the factor model for the analysis of data sets with a hierarchical structure. These Multilevel Factor Models (MFMs) have in common that—as in multilevel regression analysis—variation at the higher level is modeled using continuous random effects. In this article, we present an alternative multilevel extension of factor analysis which we call the Multilevel Mixture Factor Model (MMFM). It is based on the assumption that higher level units belong to latent classes that differ in terms of the parameters of the factor model specified for the lower level units. We demonstrate the added value of MMFM compared with MFM, both from a theoretical and applied perspective, and we illustrate the complementarity of the two approaches with an empirical application on students' satisfaction with the University of Florence. The multilevel aspect of this application is that students are nested within study programs, which makes it possible to cluster these programs based on their differences in students' satisfaction.     

The role of explicit and implicit learning processes in concept discovery

Analysis of individual learning curves and concurrent verbal protocols from three experiments concerning discovery of a non-salient verbal concept and a pictorial analogue (Chinese ideograph) of the concept show that a substantial transition phase occurs in which discrimination of exemplars from non-exemplars of the concept is above chance but not yet asymptotic. Under most conditions the ability to verbalize knowledge of the concept occurred almost simultaneously with the onset of the transition phase. However, the addition of noise in the form of false feedback (Experiment 3) created a temporary dissociation between task performance and verbalizable knowledge. Additional results suggest that individual hypothesis revision/rejection strategies affect the length of the transition phase of learning, whereas the size of the domain of hypotheses being sampled affects the number of trial blocks before the transition phase begins. The effect of feedback error on the relation between early rates of hypothesis generation and subsequent transition phase length also suggests that a strategy of quick rejection of falsified hypotheses becomes less adaptive in noisy task environments (e.g. when there are many exceptions to a rule or the concept is probabilistic). Finally, failure to find effects of variables known to affect implicit learning suggests that implicit learning processes do not play a large role in the discovery of this type of concept.     

Infants discriminate manners and paths in non-linguistic dynamic events

Do 14- to 17-month-olds notice the paths and manners of motion events? English- and Spanish-learning infants were habituated to an animated motion event including a manner (e.g., spinning) and a path (e.g., over). They were then tested on four types of events that changed either the manner, the path, both, or neither component. Both English- and Spanish-learning infants attended to changes of manner and changes of path. Thus, infants from two different language communities proved sensitive to components of events that undergird relational term learning.