Countermanding saccades: evidence against independent processing of go and stop signals

In a stop signal paradigm, subjects were instructed to make a saccade to a visual target appearing left or right of the fixation point. In 25% of the trials, an auditory stop signal was presented after a variable delay that required the subject to inhibit the saccade. Observed saccadic response times in stop failure trials were longer than predicted by Logan and Cowan's (1984) race model. Saccadic response time and amplitude decreased with the time between stop signal presentation and saccade execution, suggesting an inhibitory effect between the stop signal and the go signal processes that is not compatible with an independent race assumption. Moreover, countermanding a saccade was more difficult when stop and go signals appeared at the same location.     

Relation of maternal responsiveness during infancy to the development of behavior problems in high-risk youths

Although problematic parenting has been consistently associated with behavior problems in youths, prospective links between early parenting and childhood behavior problems are less well established. This study examined the association of maternal responsiveness (MRes) during infancy and behavior problems in middle childhood (N = 77). MRes was significantly associated with disruptive behavior problems but was unrelated to attention problems. Absence of MRes during infancy increased the risk of disruptive behavior problems in middle childhood, even with concurrent parenting and established risk factors for disruptive behavior controlled. MRes also interacted with concurrent family risk to predict disruptive behavior symptoms. These findings underscore the importance of early parenting for developmental pathways to disruptive behavior disorders in high-risk youths. The identification of a relatively modifiable early risk factor for disruptive behavior problems has important implications for prevention.     

Severe Withdrawal (and Recovery)

The problem of how to remove information from an agent's stock of beliefs is of paramount concern in the belief change literature. An inquiring agent may remove beliefs for a variety of reasons: a belief may be called into doubt or the agent may simply wish to entertain other possibilities. In the prominent AGM framework for belief change, upon which the work here is based, one of the three central operations, contraction, addresses this concern (the other two deal with the incorporation of new information). Makinson has generalised this work by introducing the notion of a withdrawal operation. Underlying the account proffered by AGM is the idea of rational belief change. A belief change operation should be guided by certain principles or integrity constraints in order to characterise change by a rational agent. One of the most noted principles within the context of AGM is the Principle of Informational Economy. However, adoption of this principle in its purest form has been rejected by AGM leading to a more relaxed interpretation. In this paper, we argue that this weakening of the Principle of Informational Economy suggests that it is only one of a number of principles which should be taken into account. Furthermore, this weakening points toward a Principle of Indifference. This motivates the introduction of a belief removal operation that we call severe withdrawal. We provide rationality postulates for severe withdrawal and explore its relationship with AGM contraction. Moreover, we furnish possible worlds and epistemic entrenchment semantics for severe withdrawals.     

Distinguishing Language from Thought: Experimental Evidence That Syntax Is Lexically Rather Than Conceptually Represented

It is generally assumed that syntax is represented linguistically rather than conceptually, consistent with the more general view that language and thought are coded separately. This claim is widely defended on logical grounds, but it has received little experimental support. In the present study, we asked Spanish and English speakers to make semantic and syntactic categorizations for pictures and their corresponding names. Consistent with past results, latencies to semantically categorize pictures and words were similar. The new finding is that participants were faster to make syntactic decisions for words compared with pictures, suggesting that syntactic features such as grammatical gender and the count-mass distinction are more closely linked to lexical than conceptual representations.     

Defying conventional wisdom: A meta-analytical examination of the differences between demographic and job-related diversity relationships with performance

Conventional wisdom in the diversity literature holds that job-related dimensions of diversity are the domain of positive performance, whereas demographic dimensions of diversity are the domain of negative performance effects. In a meta-analysis (N = 146 studies, 612 effect sizes), we show that this conclusion may be based on rater biases; it does not apply to studies involving more objective assessments of performance, assessments that cannot be influenced by knowledge of a team’s composition. We also show that the influence of job-related diversity is moderated by task complexity and that job-related diversity is more positively related to innovative performance than to in-role performance. We discuss how these results invite a reconsideration of the role of the job-related/demographic diversity distinction and provide suggestions on how to further advance our understanding of diversity’s effects.     

SUBSTANCE-ABUSING MOTHERS IN RESIDENTIAL TREATMENT WITH THEIR BABIES: IMPORTANCE OF PRE- AND POSTNATAL MATERNAL REFLECTIVE FUNCTIONING

A residential treatment program has been developed specifically for substance-abusing pregnant and parenting women in Finland, focusing on simultaneously supporting maternal abstinence from substances and the mother-baby relationship. The aims of the study are to explore maternal pre- and postnatal reflective functioning and its association with background factors, maternal exposure to trauma, and psychiatric symptoms, postnatal interaction, child development, and later child foster care placement. Participants were 34 mother-baby pairs living in three residential program units during the pre- to postnatal period. We employed self-report questionnaires on background, trauma history, and psychiatric symptoms (Brief Symptom Inventory: L.R. Derogatis, 1993; Edinburgh Postnatal Depression Scale: J.L. Cox, J.M. Holden, & R. Sagovsky, 1987; Traumatic Antecedents Questionnaire: B. Van der Kolk, 2003), videotaped mother-child interactions coded for sensitivity, control, and unresponsiveness (Care Index for Infants and Toddlers: P. Crittenden, 2003); a standardized test of child development (Bayley Scales of Infant Development-II: N. Bayley, 1993); and semistructured interviews for maternal reflective functioning (Pregnancy Interview: A. Slade, E. Bernbach, J. Grienenberger, D.W. Levy, & A. Locker, 2002; Parent Development Interview: A. Slade et al., 2005). Pre- and postnatal maternal reflective functioning (RF) was on average low, but varied considerably across participants. Average RF increased significantly during the intervention. Increase in RF level was found to be associated with type of abused substance and maternal trauma history. Mothers who showed lower postnatal RF levels relapsed to substance use more often after completing a residential treatment period, and their children were more likely to be placed in foster care. The intensive focus on maternal RF is an important direction in the development of efficacious treatment for this very high risk population.     

Therapist effects and the dissemination of cognitive behavior therapy for chronic fatigue syndrome in community-based mental health care

ObjectiveThe purpose of the present study was to explore the role of the therapist in the dissemination of manualized cognitive behavior therapy (CBT) for chronic fatigue syndrome (CFS) outside specialized treatment settings.MethodWe used the routinely collected outcome data of three community-based mental health care centers (MHCs) which implemented and sustained CBT for CFS during the course of the study. Ten therapists, who all received the same training in CBT for CFS, and 103 patients with CFS were included.ResultsRandom effects modeling revealed a significant difference in mean post-treatment fatigue between therapists. The effect of the therapist accounted for 21% of the total variance in post-treatment fatigue in our sample. This effect could be explained by the therapists’ attitude toward working with evidence-based treatment manuals as well as by the MHC where CBT for CFS was delivered.ConclusionThe context in which CBT for CFS is delivered may play an important role in the accomplishment of established therapy effects outside specialized treatment settings. Due to the small sample size of MHCs and the different implementation scenarios in which they were engaged, our findings should be interpreted as preliminary results which are in need for replication.     

Dopamine, working memory, and training induced plasticity: implications for developmental research

Cognitive deficits and particularly deficits in working memory (WM) capacity are common features in neuropsychiatric disorders. Understanding the underlying mechanisms through which WM capacity can be improved is therefore of great importance. Several lines of research indicate that dopamine plays an important role not only in WM function but also for improving WM capacity. For example, pharmacological interventions acting on the dopaminergic system, such as methylphenidate, improve WM performance. In addition, behavioral interventions for improving WM performance in the form of intensive computerized training have recently been associated with changes in dopamine receptor density. These two different means of improving WM performance--pharmacological and behavioral--are thus associated with similar biological mechanisms in the brain involving dopaminergic systems. This article reviews some of the evidence for the role of dopamine in WM functioning, in particular concerning the link to WM development and cognitive plasticity. Novel data are presented showing that variation in the dopamine transporter gene (DAT1) influences improvements in WM and fluid intelligence in preschool-age children following cognitive training. Our results emphasize the importance of the role of dopamine in determining cognitive plasticity.