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Cingulate Activation (cingulate + activation)
Selected AbstractsAnterior cingulate activation in antipsychotic-naïve first-episode schizophreniaACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2007M. Yücel Objective:, Anterior cingulate (ACC) hypo -activity is commonly observed in chronically ill schizophrenia patients. However, it is unclear whether this is secondary to persistent illness and/or medication. Method:, We examined eight antipsychotic-naïve first-episode patients and matched healthy controls undergoing PET scanning while performing the Stroop task. Results:, Group-averaged and single-subject analyses showed ACC activation in both controls and patients, albeit in different sub-regions (paracingulate and cingulate respectively). A direct comparison revealed relative under-activity of the left paracingulate cortex in patients. Conclusion:, These findings suggest that the more pervasive hypo -activation observed in chronic patients may be secondary to persistent illness and/or medication. [source] Posterior cingulate activation during moral dilemma in adolescentsHUMAN BRAIN MAPPING, Issue 8 2008Jesus Pujol Abstract Neuroimaging research examining correlates of adolescent behavioral maturation has focused largely on issues related to higher cognitive development. Currently few studies have explored neural correlates of emotional reactivity in adolescent groups. In this study, we sought to examine the nature of posterior cingulate activation during situations of moral dilemma in normal adolescents. We focused on this region because of emerging evidence that suggests its role in emotionally self-relevant mental processing. Ten healthy teenagers, aged from 14 to 16 years, underwent three fMRI sequences designed to examine (i) brain responses during moral dilemma; (ii) brain responses during passive viewing of the moral dilemma outcome; and (iii); "deactivation" during a simple cognitive task compared with resting-state activity. Our main finding was that during moral dilemma, all subjects showed significant activation of the posterior cingulate cortex, and more variable activation of the medial frontal cortex and angular gyrus. Interestingly, these findings were replicated in each subject using the passive viewing task, suggesting that the previous pattern was not specific to moral reasoning or decision making. Finally, six of the ten subjects showed deactivation of the same posterior cingulate region during the cognitive task, indicating some commonality of function between posterior cingulate activity during moral dilemmas and rest. We propose that these posterior cingulate changes may relate to basic neuronal activities associated with processing self-relevant emotional stimuli. Given the high single-subject reproducibility of posterior cingulate activations, our findings may contribute to further characterize adolescent emotional reactivity in developmental neuroimaging studies. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [source] Incentive-elicited mesolimbic activation and externalizing symptomatology in adolescentsTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2010James M. Bjork Background:, Opponent-process theories of externalizing disorders (ExD) attribute them to some combination of overactive reward processing systems and/or underactive behavior inhibition systems. Reward processing has been indexed by recruitment of incentive-motivational neurocircuitry of the ventral striatum (VS), including nucleus accumbens (NAcc). Methods:, We used functional magnetic resonance imaging (fMRI) with an incentive task to determine whether externalizing symptomatology in adolescence is correlated with an enhanced VS recruitment by cues for rewards, or by deliveries of rewards. Twelve community-recruited adolescents with externalizing disorders (AED) and 12 age/gender-matched controls responded to targets to win or avoid losing $0, $0.20, $1, $5, or an unknown amount (ranging from $0.20 to $5). Results:, Cues to respond for rewards activated the NAcc (relative to cues for no incentive), in both subject groups similarly, with greatest NAcc recruitment by cues for the largest reward. Loss-anticipatory NAcc signal increase was detected in a volume-of-interest analysis , but this increase occurred only in trials when subjects hit the target. Relative to controls, AED showed significantly elevated NAcc activation by a linear contrast between reward notification versus notification of failure to win reward. In a post hoc reanalysis, VS and pregenual anterior cingulate activation by the reward versus non-reward outcome contrast also directly correlated with Child Behavior Checklist (CBCL) Externalizing total scores (across all subjects) in lieu of a binary diagnosis. Finally, both groups showed right insula activation by loss notifications (contrasted with avoided losses). Conclusions:, Externalizing behavior, whether assessed dimensionally with a questionnaire, or in the form of a diagnostic categorization, is associated with an exaggerated limbic response to outcomes of reward-directed behavior. This could be a neurobiological signature of the behavioral sensitivity to laboratory reward delivery that is characteristic of children with externalizing symptomatology. Of interest is future research on incentive-motivational processing in more severe, clinically referred AED. [source] Post-stroke tactile allodynia and its modulation by vestibular stimulation: a MEG case studyACTA NEUROLOGICA SCANDINAVICA, Issue 6 2009P. D. McGeoch Background,,, There is behavioural evidence that caloric vestibular stimulation (CVS) can alleviate central pain. Several such patients have also noted that it reduces tactile allodynia, an especially ill-understood phenomenon in these patients. Aims of the study,,, The first aim is to use magnetoencephalography (MEG) to study neural activity associated with tactile allodynia in central post-stroke pain (CPSP). The second is to assess how this would be affected, if at all, by CVS. The third is to assess the ability of the VESTAL solution for MEG to detect anterior cingulate activation. Methods,,, A 58-year-old woman with CPSP, and marked unilateral tactile allodynia, participated in a MEG study with imaging pre- and post-CVS. Results,,, Tactile simulation within the patient's allodynic area resulted in contralateral activation of the primary motor and anterior cingulate cortices, which had normalized 24 h post-CVS. Conclusions,,, We suggest that the unexpected primary motor cortex activation in response to light touch in the allodynic area arises from inappropriate activation of a normal mechanism, which may occur when a threat to homeostasis is present, to lower motor thresholds and allow for more rapid performance of corrective actions. We propose this may be mediated by the interoceptive cortex in the dorsal posterior insula. [source] Posterior cingulate activation during moral dilemma in adolescentsHUMAN BRAIN MAPPING, Issue 8 2008Jesus Pujol Abstract Neuroimaging research examining correlates of adolescent behavioral maturation has focused largely on issues related to higher cognitive development. Currently few studies have explored neural correlates of emotional reactivity in adolescent groups. In this study, we sought to examine the nature of posterior cingulate activation during situations of moral dilemma in normal adolescents. We focused on this region because of emerging evidence that suggests its role in emotionally self-relevant mental processing. Ten healthy teenagers, aged from 14 to 16 years, underwent three fMRI sequences designed to examine (i) brain responses during moral dilemma; (ii) brain responses during passive viewing of the moral dilemma outcome; and (iii); "deactivation" during a simple cognitive task compared with resting-state activity. Our main finding was that during moral dilemma, all subjects showed significant activation of the posterior cingulate cortex, and more variable activation of the medial frontal cortex and angular gyrus. Interestingly, these findings were replicated in each subject using the passive viewing task, suggesting that the previous pattern was not specific to moral reasoning or decision making. Finally, six of the ten subjects showed deactivation of the same posterior cingulate region during the cognitive task, indicating some commonality of function between posterior cingulate activity during moral dilemmas and rest. We propose that these posterior cingulate changes may relate to basic neuronal activities associated with processing self-relevant emotional stimuli. Given the high single-subject reproducibility of posterior cingulate activations, our findings may contribute to further characterize adolescent emotional reactivity in developmental neuroimaging studies. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [source] | ||||||||||