Human brain mapping
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Human brain mapping · Dec 2016
Pain networks from the inside: Spatiotemporal analysis of brain responses leading from nociception to conscious perception.
Conscious perception of painful stimuli needs the contribution of an extensive cortico-subcortical network, and is completed in less than one second. While initial activities in operculo-insular and mid-cingulate cortices have been extensively assessed, the activation timing of most areas supporting conscious pain has barely been studied. Here we used intracranial EEG to investigate the dynamics of 16 brain regions (insular, parietal, prefrontal, cingulate, hippocampal and limbic) during the first second following nociceptive-specific laser pulses. ⋯ Nociceptive inputs reach simultaneously sensory and limbic networks, probably through parallel spino-thalamic and spino-parabrachial pathways, and the initial limbic activation precedes conscious perception of pain. Access of sensory information to consciousness develops concomitant to fronto-parietal activity, while late-occurring responses in the hippocampal region, perigenual and posterior cingulate cortices likely underlie processes linked to memory encoding, self-awareness and pain modulation. Hum Brain Mapp 37:4301-4315, 2016. © 2016 Wiley Periodicals, Inc.
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Human brain mapping · Dec 2016
A proactive task set influences how response inhibition is implemented in the basal ganglia.
Increasing a participant's ability to prepare for response inhibition is known to result in longer Go response times and is thought to engage a "top-down fronto-striatal inhibitory task set." This premise is supported by the observation of anterior striatum activation in functional magnetic resonance imaging (fMRI) analyses that focus on uncertain versus certain Go trials. It is assumed that setting up a proactive inhibitory task set also influences how participants subsequently implement stopping. ⋯ Successful stopping was associated with increased STN activity when Stop trials were infrequent and increased caudate head activation when Stop trials were more likely, suggesting a different implementation of reactive response inhibition by the basal ganglia for differing degrees of proactive response control. Hum Brain Mapp 37:4706-4717, 2016. © 2016 Wiley Periodicals, Inc.
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Human brain mapping · Dec 2016
Altered anterior-posterior connectivity through the arcuate fasciculus in temporal lobe epilepsy.
How the interactions between cortices through a specific white matter pathway change during cognitive processing in patients with epilepsy remains unclear. Here, we used surface-based structural connectivity analysis to examine the change in structural connectivity with Broca's area/the right Broca's homologue in the lateral temporal and inferior parietal cortices through the arcuate fasciculus (AF) in 17 patients with left temporal lobe epilepsy (TLE) compared with 17 healthy controls. Then, we investigated its functional relevance to the changes in task-related responses and task-modulated functional connectivity with Broca's area/the right Broca's homologue during a semantic classification task of a single word. ⋯ The results suggest that the change in the structural connectivity through the left frontal-temporal AF pathway underlies the altered functional networks between the frontal and temporal cortices during the language-related processing in patients with left TLE. The left frontal-parietal AF pathway might be employed to connect anterior and posterior brain regions during language processing and compensate for the compromised left frontal-temporal AF pathway. Hum Brain Mapp 37:4425-4438, 2016. © 2016 Wiley Periodicals, Inc.