222 research outputs found

    State Effects of Two Forms of Meditation on Prefrontal EEG Asymmetry in Previously Depressed Individuals

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    We investigated state effects of two forms of meditation on electroencephalography prefrontal α-asymmetry, a global indicator of approach versus withdrawal motivation and related affective state. A clinical series of previously depressed individuals were guided to practice either mindfulness breathing meditation (N = 8) or a form of meditation directly aimed at cultivating positive affect, loving kindness or metta meditation (N = 7). Prefrontal asymmetry was assessed directly before and after the 15-min meditation period. Results showed changes in asymmetry towards stronger relative left prefrontal activation, i.e., stronger approach tendencies, regardless of condition. Further explorations of these findings suggested that responses were moderated by participants’ tendencies to engage in ruminative brooding. Individuals high in brooding tended to respond to breathing meditation but not loving kindness meditation, while those low in brooding showed the opposite pattern. Comparisons with an additionally recruited “rest” group provided evidence suggesting that changes seen were not simply attributable to habituation. The results indicate that both forms of meditation practice can have beneficial state effects on prefrontal α-asymmetry and point towards differential indications for offering them in the treatment of previously depressed patients

    The effects of cognitive-behavioural therapy on mood-related ruminative response style in depressed adolescents

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    <p>Abstract</p> <p>Background</p> <p>A mood-related ruminative response style increases the risk of onset and persistence of depression. This preliminary study investigated whether, in depressed adolescents, cognitive-behaviour therapy reduces mood-related ruminative response style. Whether specific factors within the rumination scale were differentially affected by CBT is also reported.</p> <p>Methods</p> <p>26 depressed adolescents were randomised to receiving serotonin-specific reuptake inhibitor antidepressants (SSRI) plus psychosocial treatment as usual or SSRI and psychosocial treatment as usual plus CBT. Ruminative response style and depressive symptoms were measured at baseline and after 30 weeks of treatment, with the Responses to Depression Questionnaire and Mood and Feelings Questionnaire.</p> <p>Results</p> <p>There were significantly greater reductions in ruminations in the CBT group compared to the non-CBT group (<it>p </it>= .002). There was no significant difference in the reduction in self-reported depressive symptoms between the groups. Rumination was reduced to levels of never-depressed controls in adolescents who had recovered from depression and received CBT. There were greater falls in the CBT group in the more pathological 'brooding' factor of rumination.</p> <p>Conclusion</p> <p>These findings suggest that adding CBT to SSRI medication in the presence of active clinical care causes a greater reduction in mood-related ruminative response style in depressed adolescents. This may reduce the risk of future relapse.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCNT83809224.</p

    Methods to create a stringent selection system for mammalian cell lines

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    The efficient establishment of high protein producing recombinant mammalian cell lines is facilitated by the use of a stringent selection system. Here, we describe two methods to create a stringent selection system based on the Zeocin resistance marker. First, we cloned increasingly longer stretches of DNA, encoding a range of 8–131 amino acids immediately upstream of the Zeocin selection marker gene. The DNA stretches were separated from the open reading frame of the selection marker gene by a stopcodon. The idea behind this was that the translation machinery will first translate the small peptide, stop and then restart at the AUG of the Zeocin marker. This process, however, will become less efficient with increasingly longer stretches of DNA upstream of the Zeocin marker that has to be translated first. This would result in lower levels of the Zeocin selection marker protein and thus a higher selection stringency of the system. Secondly, we performed a genetic screen to identify PCR induced mutations in the Zeocin selection protein that functionally impair the selection marker protein. Both the insertion of increasingly longer peptides and several Zeocin selection protein mutants resulted in a decreasing number of stably transfected colonies that concomitantly displayed higher protein expression levels. When the Zeocin mutants were combined with very short small peptides (8–14 amino acids long), this created a flexible, high stringency selection system. The system allows the rapid establishment of few, but high protein producing mammalian cell lines

    The Effects of Experimentally Induced Rumination, Positive Reappraisal, Acceptance, and Distancing When Thinking About a Stressful Event on Affect States in Adolescents

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    The current study compares the effects of experimentally induced rumination, positive reappraisal, distancing, and acceptance on affect states in adolescents aged 13–18. Participants (N = 160) were instructed to think about a recent stressful event. Next, they received specific instructions on how to think about that event in each condition. Manipulation checks revealed that the manipulations were successful, except for acceptance. The two most reported events were “a fight” and “death of loved one”. Results showed that positive reappraisal (i.e., thinking about the benefits and personal growth) caused a significantly larger increase in positive affect and decrease in negative affect compared to rumination, distancing, and acceptance. Current findings implicate that positive reappraisal seems an adequate coping strategy in the short-term, and therefore could be applied in interventions for youth experiencing difficulties managing negative affect. Future research should focus on long-term effects of these cognitive strategies and on more intensive training of acceptance

    Incorporating Model Uncertainty into Spatial Predictions

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    We consider a modeling approach for spatially distributed data. We are concerned with aspects of statistical inference for Gaussian random fields when the ultimate objective is to predict the value of the random field at unobserved locations. However the exact statistical model is seldom known before hand and is usually estimated from the very same data relative to which the predictions are made. Our objective is to assess the effect of the fact that the model is estimated, rather than known, on the prediction and the associated prediction uncertainty. We describe a method for achieving this objective. We, in essence, consider the best linear unbiased prediction procedure based on the model within a Bayesian framework. These ideas are implemented for the spring temperature over the region in the north- ern United States based on the stations in the United States historical climatological network reported in Karl, Williams, Quinlan &amp; Boden (1990)

    Affective regulation of cognitive-control adjustments in remitted depressive patients after acute tryptophan depletion

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    Negative affect in healthy populations regulates the appraisal of demanding situations, which tunes subsequent effort mobilization and adjustments in cognitive control. In the present study, we hypothesized that dysphoria in depressed individuals similarly modulates this adaptation, possibly through a neural mechanism involving serotonergic regulation. We tested the effect of dysphoria induced by acute tryptophan depletion (ATD) in remitted depressed patients on conflict adaptation in a Simon task. ATD temporarily lowers the availability of the serotonin precursor L-Tryptophan and is known to increase depressive symptoms in approximately half of remitted depressed participants. We found that depressive symptoms induced by ATD were associated with increased conflict adaptation. Our finding extends recent observations implying an important role of affect in regulating conflict-driven cognitive control

    Down-Regulation of Negative Emotional Processing by Transcranial Direct Current Stimulation: Effects of Personality Characteristics

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    Evidence from neuroimaging and electrophysiological studies indicates that the left dorsolateral prefrontal cortex (DLPFC) is a core region in emotional processing, particularly during down-regulation of negative emotional conditions. However, emotional regulation is a process subject to major inter-individual differences, some of which may be explained by personality traits. In the present study we used transcranial direct current stimulation (tDCS) over the left DLPFC to investigate whether transiently increasing the activity of this region resulted in changes in the ratings of positive, neutral and negative emotional pictures. Results revealed that anodal, but not cathodal, tDCS reduced the perceived degree of emotional valence for negative stimuli, possibly due to an enhancement of cognitive control of emotional expression. We also aimed to determine whether personality traits (extraversion and neuroticism) might condition the impact of tDCS. We found that individuals with higher scores on the introversion personality dimension were more permeable than extraverts to the modulatory effects of the stimulation. The present study underlines the role of the left DLPFC in emotional regulation, and stresses the importance of considering individual personality characteristics as a relevant variable, although replication is needed given the limited sample size of our study
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