Motor timing deficits in community and clinical boys with hyperactive behavior: the effect of methylphenidate on motor timing

In a previous paper we showed that community children with hyperactive behavior were more inconsistent than controls in the temporal organization of their motor output. In this study we investigated: (1) various aspects of motor timing processes in 13 clinically diagnosed boys with attention deficit hyperactivity disorder (ADHD) who were compared to 11 community boys with hyperactive behavior and to a control group and (2) the effect of methylphenidate on the motor timing processes in the clinical group with ADHD in a double blind, cross-over, medication-placebo design, including 4 weeks of medication. The clinical group with ADHD, like the community group with hyperactivity, showed greater variability in sensorimotor synchronization and in sensorimotor anticipation relative to controls. The clinical group was also impaired in time perception, which was spared in the community group with hyperactivity. The persistent, but not the acute dose, of methylphenidate reduced the variability of sensorimotor synchronization and anticipation, but had no effect on time perception. This study shows that motor timing functions are impaired in both clinical and community children with hyperactivity. It is the first study to show the effectiveness of persistent administration of methylphenidate on deficits in motor timing in ADHD children and extends the use of methylphenidate from the domain of attentional and inhibitory functions to the domain of executive motor timing.     

Judging the Probability of Hypotheses Versus the Impact of Evidence: Which Form of Inductive Inference Is More Accurate and Time‐Consistent?

Inductive reasoning requires exploiting links between evidence and hypotheses. This can be done focusing either on the posterior probability of the hypothesis when updated on the new evidence or on the impact of the new evidence on the credibility of the hypothesis. But are these two cognitive representations equally reliable? This study investigates this question by comparing probability and impact judgments on the same experimental materials. The results indicate that impact judgments are more consistent in time and more accurate than probability judgments. Impact judgments also predict the direction of errors in probability judgments. These findings suggest that human inductive reasoning relies more on estimating evidential impact than on posterior probability.     

Contingent application of the cancellation editing operation: the role of semantic relatedness between risky outcomes

This article presents findings on the restructuring component of the decision process. Two experiments are described employing hypothetical vacation choice dilemmas. The aim was to explore the conditions under which outcomes common to two risky prospects with the same probabilities of occurrence are or are not cancelled and how consequent decisions are influenced. The design of the options presented to participants was based on pilot work to establish appropriate contexts. The key independent variable was the semantic relatedness between outcomes of the same risky prospect. The main finding was that the participants did not cancel the outcome shared by two prospects when it was semantically related to another outcome within the same prospect. In this case, the prospect with greater risk was chosen significantly more frequently in comparison to when the common outcome was unrelated to other outcomes. An interpretation of the findings is presented in terms of contingent editing processes. Copyright © 2004 John Wiley & Sons, Ltd.     

Determinants of confirmation

Epistemologists often suppose that the extent to which evidencee confirms hypothesisH depends on probabilities involvinge andH, and nothing more. We show experimentally that human reasoners sometimes violate this assumption.     

Social Anxiety Disorder and Social Support Behavior in Friendships

Relationship quality is a strong predictor of health outcomes, and individuals with social anxiety disorder (SAD) report increased interpersonal impairment. However, there are few studies testing the effect of SAD on friendships and it is thus unclear whether there are behavioral differences that distinguish friendships in which a target individual has SAD from friendships in which the target individual does not have SAD. We tested for differences in the provision and receipt of support behaviors as a function of having a SAD diagnosis and accounting for comorbid depressive symptoms. Participants with SAD (n = 90) and their friends engaged in support conversations that were coded using the Social Support Interaction Coding System. Structural equation modeling revealed some differences between participants and friends when accounting for depression. Specifically, friends of participants with SAD and comorbid depression engaged in fewer positive helper behaviors than the friends of participants who did not have SAD or comorbid depression. Additionally, dyads in which the primary participant had SAD engaged in more off-task behaviors. Results suggest that SAD does not result in global interpersonal impairment, but that receipt of positive support behaviors from friends may differ as a function of SAD and comorbid depression. Interpersonal interventions aimed at increasing adaptive friendships and aspects of CBT that target subtle avoidance (e.g., safety behaviors) may be useful in facilitating more satisfactory relationships for these individuals.     

Lateralization of visuospatial attention across face regions varies with emotional prosody

It is well-established that linguistic processing is primarily a left-hemisphere activity, while emotional prosody processing is lateralized to the right hemisphere. Does attention, directed at different regions of the talker’s face, reflect this pattern of lateralization? We investigated visuospatial attention across a talker’s face with a dual-task paradigm, using dot detection and language comprehension measures. A static image of a talker was shown while participants listened to speeches spoken in two prosodic formats, emotional or neutral. A single dot was superimposed on the speaker’s face in one of 4 facial regions on half of the trials. Dot detection effects depended on emotion condition—in the neutral condition, discriminability was greater for the right-, than for the left-, side of the face image, and at the mouth, compared to the eye region. The opposite effects occurred in the emotional prosody condition. The results support a model wherein visuospatial attention used during language comprehension is directed by the left hemisphere given neutral emotional prosody, and by the right hemisphere given primarily negative emotional prosodic cues.     

Performance of children with attention deficit hyperactivity disorder (ADHD) on a test battery of impulsiveness.

Children with ADHD were compared to healthy controls on a task battery of cognitive control, measuring motor inhibition (Go/No-Go and Stop tasks), cognitive inhibition (motor Stroop and Switch tasks), sustained attention and time discrimination. Children with ADHD showed an inconsistent and premature response style across all 6 tasks. In addition they showed task-specific impairments in measures of sustained attention, time discrimination, and motor inhibition, but spared cognitive inhibition. Measures of impairment correlated with behavioral hyperactivity and with each other, suggesting that they measure interrelated aspects of a multifaceted construct of cognitive impulsiveness. The task battery as a whole showed 76% correct discrimination of cases and controls.     

MAPK activation in the hippocampus in vivo is correlated with experimental setting

The mitogen-activated protein kinase (MAPK) pathway is an evolutionarily conserved signaling cascade involved in both synaptic plasticity and memory formation. Following our recent observation of translation regulation in taste learning and memory, we aimed to study MAPK-dependent translation regulation in long-term potentiation (LTP), a cellular model of learning and memory. We first analyzed ERK1/2 activation following high-frequency stimulation in the dentate gyrus (DG) of the hippocampus, in vivo. Surprisingly, our results indicate that the activation of both ERK2 and p38 was strongly affected by the order in which the DG was dissected out, but not by other experimental parameters. Specifically, we found that ERK2 and p38 phosphorylation were higher in the second than in the first dentate gyrus removed (up to 30s apart). Similar results were obtained when we isolated the 'order of removal' factor by looking at MAPK phosphorylation in rats that had not undergone any electrophysiological procedure (i.e., na?ve rats). This effect is so robust, that it probably masks the effect of LTP induction on MAPK activation. We suggest that some of the correlations found between MAPK activation and brain function in vivo may be due to cellular stress. In addition, careful experimental procedures and control are indispensable in the analysis of biochemical correlations of post-translation modifications that subserve both general neuronal function and synaptic plasticity.     

TelEMA: a low-cost and user-friendly telephone assessment platform

Ecological momentary assessment (EMA), or the repeated assessment of individuals’ behaviors and experiences over time, is a methodologically advantageous approach to the study of psychological constructs. Recently, advances in computer technology have allowed for EMA research to be conducted in a more convenient, automated, and secure manner by administering surveys on participants’ telephones and storing the results directly to a central server. The present article introduces TelEMA, an easy-to-use, low-cost telephone assessment platform for clinical and research applications. A single server running TelEMA can be shared among many experimenters, studies, and participants simultaneously. TelEMA routes telephone calls and text messages through a third-party service, so experimenters may conduct studies with no up-front cost or technical expertise. TelEMA provides a secure Web interface for experimenters or clinicians to design studies, enroll participants, monitor compliance, and collate response data from anywhere. Participants complete surveys using their own telephones. Surveys may contain keypress or voice recording questions, and the timing and content of each survey may be randomized and customized. A pilot study was conducted in which individuals used the TelEMA system to complete four randomly timed surveys per day for one week; the surveys assessed state affect and social anxiety. Results indicated that participants found TelEMA easy to use and secure, and compliance rates were on par with other EMA methods using mobile devices. Overall, TelEMA is a practical and robust system that enables fast and inexpensive deployment of EMAs.