Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD?

Contains fulltext : 48908.pdf (publisher's version ) (Closed access)We examined the effect of methylphenidate (Mph) on inhibition and several other cognitive abilities in 43 adults with Attention Deficit Hyperactivity Disorder (ADHD) by use of Conners' Continuous Performance Test (CPT) and the Change Task (ChT), an extension of the Stop Signal Test (SST). In a double blind, cross-over, placebo controlled study with Mph, tests were administered during the third week of individually titrated treatment with Mph (maximum dose 1 mg / kg / day) and during the third week of treatment with placebo. We established large medication effects for commission errors, standard error of mean reaction time, and attentiveness on the CPT, as well as moderate medication effects for mean reaction time on the CPT and response re-engagement speed on the ChT. For Stop Signal Reaction Time (SSRT) on the ChT, we also established large effects of Mph, but only in a group of participants who showed slow SSRTs on placebo. Mph indeed ameliorates inhibition, which is the core problem of ADHD, and certain other cognitive abilities in adults with ADHD

The Role of Stimulus Salience and Attentional Capture Across the Neural Hierarchy in a Stop-Signal Task

Inhibitory motor control is a core function of cognitive control. Evidence from diverse experimental approaches has linked this function to a mostly right-lateralized network of cortical and subcortical areas, wherein a signal from the frontal cortex to the basal ganglia is believed to trigger motor-response cancellation. Recently, however, it has been recognized that in the context of typical motor-control paradigms those processes related to actual response inhibition and those related to the attentional processing of the relevant stimuli are highly interrelated and thus difficult to distinguish. Here, we used fMRI and a modified Stop-signal task to specifically examine the role of perceptual and attentional processes triggered by the different stimuli in such tasks, thus seeking to further distinguish other cognitive processes that may precede or otherwise accompany the implementation of response inhibition. In order to establish which brain areas respond to sensory stimulation differences by rare Stop-stimuli, as well as to the associated attentional capture that these may trigger irrespective of their task-relevance, we compared brain activity evoked by Stop-trials to that evoked by Go-trials in task blocks where Stop-stimuli were to be ignored. In addition, region-of-interest analyses comparing the responses to these task-irrelevant Stop-trials, with those to typical relevant Stop-trials, identified separable activity profiles as a function of the task-relevance of the Stop-signal. While occipital areas were mostly blind to the task-relevance of Stop-stimuli, activity in temporo-parietal areas dissociated between task-irrelevant and task-relevant ones. Activity profiles in frontal areas, in turn, were activated mainly by task-relevant Stop-trials, presumably reflecting a combination of triggered top-down attentional influences and inhibitory motor-control processes

Calciphylaxis in chronic renal failure: An approach to risk factors

We present a case of calcifying panniculitis due to calciphylaxis in a nontherapy compliance 65-year-old man suffering from chronic renal failure. Calciphylaxis, a life threatening condition, is characterized by high calcium × phosphate product, presence of calcium crystals in the skin and secondary hyperparathyroidism. The clinical presentation includes painful firm plaques, which could progress to nonhealing ulcers. A review of literature is given with emphasis on identification of risk factors and early diagnosis

Critical social thinking

As technology, globalization, changing work demands, and a growing reliance on teams are changing the work environment, the social complexity surrounding work functions is increasing dramatically. While a variety of socially relevant knowledge, skills, and abilities (KSAs) have been examined, we argue that studying them in isolation is no longer sufficient, as individuals require a repertoire of KSAs that must be utilized in combination to be effective in complex social situations. Thus, we propose the construct critical social thinking (CST), a holistic, integrated approach to understanding the processes that enable individuals to function in such settings, and the KSAs that are necessary for each process. Because the significance of the CST construct is closely tied to the growing need for it in practice, we also integrate disparate training findings and link them to components of our conceptual model, enabling us to put forth initial insights regarding the approaches through which CST can be trained effectively