383 research outputs found
Gray’s revised Reinforcement Sensitivity Theory in relation to Attention-Deficit/Hyperactivity and Tourette-like behaviors in the general population
Attention-Deficit/Hyperactivity Disorder (ADHD) and Tourette Syndrome (TS) present as distinct conditions clinically; however, they show comorbidity and inhibitory control deficits have been proposed to underlie both. The role of reinforcement sensitivity in ADHD has been studied previously, but no study has addressed this in relation to TS-like behaviors in the general population. The present study examined these associations within the remit of the revised Reinforcement Sensitivity Theory (rRST). One hundred and thirty-eight participants completed psychometric measures of the rRST, and self-report checklists for ADHD- and TS-like behaviors
Tourette-like behaviors in the normal population are associated with hyperactive/impulsive ADHD-like behaviors but do not relate to deficits in conditioned inhibition or response inhibition
Attention-Deficit Hyperactivity Disorder (ADHD) and Tourette Syndrome (TS) present as distinct conditions clinically; however, comorbidity and inhibitory control deficits have been proposed for both. Whilst such deficits have been studied widely within clinical populations, findings are mixed—partly due to comorbidity and/or medication effects—and studies have rarely distinguished between subtypes of the disorders. Studies in the general population are sparse. Using a continuity approach, the present study examined (i) the relationships between inattentive and hyperactive/impulsive aspects of ADHD and TS-like behaviors in the general population, and (ii) their unique associations with automatic and executive inhibitory control, as well as (iii) yawning (a proposed behavioural model of TS).One hundred and thirty-eight participants completed self-report measures for ADHD and TS-like behaviors as well as yawning, and a conditioned inhibition task to assess automatic inhibition. A sub-sample of fifty-four participants completed three executive inhibition tasks. An exploratory factor analysis of the TS behaviour checklist supported a distinction between phonic and motorlike pure TS behaviors. Whilst hyperactive/impulsive aspects of ADHD were associated with increased pure and compulsive TS-like behaviors, in attention in isolation was related to reduced obsessive-compulsive TS-like behaviors. TS-like behaviors were associated with yawning during situations of inactivity, and specifically motor TS was related to yawning during stress. Phonic TS and inattention aspects of ADHD were associated with yawning during concentration/activity. Whilst executive interference control deficits were linked to hyperactive/impulsive ADHD-like behaviors, this was not the case for inattentive ADHD or TS-like behaviors, which instead related to increased performance on some measures. No associations were observed for automatic conditioned inhibition
Enabling Personalized Composition and Adaptive Provisioning of Web Services
The proliferation of interconnected computing devices is fostering the emergence of environments where Web services made available to mobile users are a commodity. Unfortunately, inherent limitations of mobile devices still hinder the seamless access to Web services, and their use in supporting complex user activities. In this paper, we describe the design and implementation of a distributed, adaptive, and context-aware framework for personalized service composition and provisioning adapted to mobile users. Users specify their preferences by annotating existing process templates, leading to personalized service-based processes. To cater for the possibility of low bandwidth communication channels and frequent disconnections, an execution model is proposed whereby the responsibility of orchestrating personalized processes is spread across the participating services and user agents. In addition, the execution model is adaptive in the sense that the runtime environment is able to detect exceptions and react to them according to a set of rules
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The neural correlates of reinforcement sensitivity theory: a systematic review of the (f)MRI literature
Objectives: Reinforcement Sensitivity Theory (RST) is a theory of motivation, emotion and learning, that has been translated into an account of personality. RST proposes neural structures that form the basis of systems responsible for reward (BAS), punishment (FFFS) and conflict processing (BIS). This systematic review collated studies examining psychometric measures of RST alongside structural and function MRI data to (i) examine how psychometric RST is associated with the proposed neural topologies of RST, (ii) identify any common associations between psychometric RST and other brain regions, and (iii) provide recommendations for advancing the current literature base.
Methods: Initial search terms identified 10952 papers. After processing, 39 papers that investigated the association between RST scales and neural functioning in healthy adult samples were included in this review.
Results: There was general support for associations between the BAS and the structure/activity of the pre-frontal cortex and ventral striatum with some additional findings for the ventral pallidum and ventral tegmental area. There was also some support for associations between BIS/FFFS and structure/activity of frontal regions, cingulate cortices and the amygdala.
Conclusions: Overall, psychometric correlates of RST were associated with activity in proposed neural circuitry, with the most consistent support being found for the BAS; however, psychometric and experimental limitations still hamper the differentiation of the BIS and FFFS systems in their activation of deeper brain networks. Future studies need to include revised RST scales that separate the BIS and FFFS and implement more rigorous tasks that allow for the examination of each system both independently and codependently
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Effects of system- and media-driven immersive capabilities on presence and affective experience
Virtual reality (VR) is receiving widespread attention as a delivery tool for exposure therapies. The advantage offered by VR over traditional technology is a greater sense of presence and immersion, which magnifies user effects and enhances the effectiveness of exposure-based interventions. The current study systematically examined the basic factors involved in generating presence in VR as compared to standard technology, namely (1) system-driven factors that are exclusive to VR devices while controlling general factors such as field of view and image quality; (2) media-driven factors of the virtual environment eliciting motivational salience through different levels of arousal and valence (relaxing, exciting and fear evoking stimuli); and (3) the effects of presence on magnifying affective response. Participants (N = 14) watched 3 different emotionally salient videos (1 × fear evoking, 1 × relaxing and 1 × exciting) in both viewing modes (VR and Projector). Subjective scores of user experience were collected as well as objective EEG markers of presence (frontal alpha power, theta/beta ratio). Subjective and objective presence was significantly greater in the VR condition. There was no difference in subjective or objective presence for stimulus type, suggesting presence is not moderated by arousal, but may be reliant on activation of motivational systems. Finally, presence did not magnify feelings of relaxation or excitement, but did significantly magnify users’ experience of fear when viewing fear evoking stimuli. This is in line with previous literature showing strong links between presence and generation of fear, which is vital in the efficacy of exposure therapies
Neurophysiological correlates of excitement in men with recent-onset psychosis
Objective: Right frontal function, as indicated by the N200 component of the event-related potential during target detection, has previously been associated with excitement (excitement, impulsivity, hostility, uncooperativeness) in men with a long-term diagnosis of schizophrenia. The current study investigated excitement in relation to N200 in men who had recently experienced their first episode of psychosis.
Subjects and methods: Twenty men who had recently suffered their first psychotic episode underwent a clinical interview and auditory oddball task.
Results: Multiple linear regression analysis showed that 58% of the variance in the excitement symptom cluster was explained by a positive association with frontal midline N200 amplitude and an inverse association with right frontal N200 amplitude. The latter was not apparent in the initial correlation, suggesting suppression by the midline activity. These associations were not explained by drug use, medication or negative symptoms. However, the correlation between excitement and midline N200 was stronger in drug users, and that between right frontal N200 and excitement was stronger in nonusers.
Conclusion: Findings support the independent contributions to excitement of mechanisms reflected in midline and right frontal N200 amplitude respectively during the early stages of psychosis
Experimental and computational study of the low-density plasma in the outer regions of a theta pinch
PeroxiBase: a database with new tools for peroxidase family classification
Peroxidases (EC 1.11.1.x), which are encoded by small or large multigenic families, are involved in several important physiological and developmental processes. They use various peroxides as electron acceptors to catalyse a number of oxidative reactions and are present in almost all living organisms. We have created a peroxidase database (http://peroxibase.isb-sib.ch) that contains all identified peroxidase-encoding sequences (about 6000 sequences in 940 organisms). They are distributed between 11 superfamilies and about 60 subfamilies. All the sequences have been individually annotated and checked. PeroxiBase can be consulted using six major interlink sections ‘Classes’, ‘Organisms’, ‘Cellular localisations’, ‘Inducers’, ‘Repressors’ and ‘Tissue types’. General documentation on peroxidases and PeroxiBase is accessible in the ‘Documents’ section containing ‘Introduction’, ‘Class description’, ‘Publications’ and ‘Links’. In addition to the database, we have developed a tool to classify peroxidases based on the PROSITE profile methodology. To improve their specificity and to prevent overlaps between closely related subfamilies the profiles were built using a new strategy based on the silencing of residues. This new profile construction method and its discriminatory capacity have been tested and validated using the different peroxidase families and subfamilies present in the database. The peroxidase classification tool called PeroxiScan is accessible at the following address: http://peroxibase.isb-sib.ch/peroxiscan.php
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Reduction in lower-alpha power during Ganzfeld flicker stimulation is associated with the production of imagery and trait positive schizotypy
Light-flicker Ganzfeld (LFG) induces a lower to upper-alpha frequency shift. However, it is unclear how this neurophysiological response might relate to LFG-induced pseudo-hallucinatory phenomena. It is also unknown whether emotional states (e.g., fear) or traits associated with risk for psychosis (e.g., proneness to perceptual anomalies, ability to produce vivid mental imagery) affect such neurophysiological and/or perceptual responses to LFG. The present study investigated alpha sub-bands during LFG across several flicker frequencies, in relation to individual differences in propensity for Ganzfeld-induced imagery (GI), positive schizotypy and trait mental imagery, and in relation to manipulations of affective state. Given previously reported sex differences in risk for psychosis and response to Ganzfeld, the effect of sex on GI was also studied. Forty-six healthy adults (16 men) completed psychometric measures of trait mental imagery and positive schizotypy before undergoing three LFG (20 min each) conditions. In each condition, participants wore white-out goggles and listened to either mood-inducing soundscapes (fear, serenity) or pink noise (control) through headphones. Greatest propensity for GI arose between 13.1 and 16.0 Hz flicker, with a peak at 16.0 Hz flicker. Occipital lower-alpha was reduced for lower flicker frequencies (13.1–16.0 Hz) and was inversely associated with GI. Upper-alpha power was not significantly related to GI or to other measures. Fear-induction was associated with reduction in alpha power, but did not significantly affect GI. Men reported more GI than women. Findings support a role for cortical destabilisation, as reflected in reduced lower-alpha, in perceptual anomalies; and, by extension, LFG as an experimental model of liability for psychosis
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Perfectionism, personality, and affective experiences: New insights from revised Reinforcement Sensitivity Theory
Previous studies have linked perfectionism to differences in reinforcement sensitivity, but findings have been mixed. The present study explored the relationships between three forms of perfectionism (self-oriented, other-oriented, socially prescribed) and components of the revised Reinforcement Sensitivity Theory of personality in relation to the experience of positive and negative affect. In a sample of 388 university students, we found consistent evidence of significant bivariate and semipartial correlations controlling for the overlap between the three forms of perfectionism: self-oriented perfectionism showed positive relationships with the Behavioral Approach System (BAS), the Behavioral Inhibition System (BIS), and the Fight-Flight-Freeze System (FFFS); other-oriented perfectionism showed a negative relationship with the BIS (and was unrelated to the FFFS); and socially prescribed perfectionism showed positive relationships with the BIS and BAS impulsiveness, and a negative relationship with BAS goal-drive persistence (and was unrelated to the FFFS). Furthermore, mediation analyses indicated that the reinforcement sensitivity components (BIS and BAS, but not FFFS) explained differences in how the three forms of perfectionism predicted recent positive and negative affect. These findings open up new empirical avenues in suggesting that fundamental emotion-motivational systems play a key role in the relationship of perfectionism and affective experiences
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