Artikel
Response inhibition and its inhibitory network. fMRI differentiates inhibitory and attentional regions during response inhibition – key information for precise neurosurgery
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Veröffentlicht: | 8. Juni 2016 |
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Gliederung
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Objective: “Response inhibition” characterizes the ability to supress an initiated motor action. Dysfunction of response inhibition is seen in many psychiatric diseases, like addictive disorders, attention deficit/ hyperactive disorders, schizophrenia, bipolar disorders and others. Differentiating key regions of response inhibition may in the future be important for precise treatment like deep brain stimulation (DBS). The objective of the study was to show the explicit functional region of inhibition and to distinguish inhibition from an attentional network.
Method: In this functional magnetic resonance imaging (fMRI) study we modified a stop-signal-task by adding an attentional capture task in order to differentiate between attentional and inhibitory regions of the brain during response inhibition. We examined 28 healthy volunteers and performed the modified stop-signal-task in a 3Tesla MRI. The data were analysed and processed with SPM8 (Matlab 2010).
Results: Successful stopping showed a wide activation of a right accentuated frontal-striatal as well as parietal regions. Especially insula (Ins, p<0.001), right inferior frontal cortex (IFG,p<0.001), pre-supplementary-motor-area (preSMA,p<0.001) and the subthalamic nucleus (STN, p=0,019) showed significant activation. The attentional capture task showed significant activation of bilateral inferior parietal regions (p<0,001) and the right inferior frontal junction (IFJ, p=0,014). Contrasting successful stopping to attentional capture reveals significant activation of insula (p<0.001), middle frontal gyrus (p<0.001) and preSMA (p=0.001); however no activation is seen of the IFJ.
Conclusions: Hence, we conclude that response inhibition is mainly driven by a right accentuated inhibitory network including the ventral inferior frontal region IFG, the insula and the preSMA, whereas attentional functions are driven by a bilateral fronto-parietal network including the dorsal prefrontal region IFJ and inferior parietal cortex . This study indicates that targeting ventral prefrontal regions might be promising for DBS to treat psychiatric diseases like treatment-refractory addiction. Additionally neurosurgeons should consider the functional importance of the region on planning operative approaches.