scholarly journals Modulating Inhibitory Control Processes Using Individualized High Definition Theta Transcranial Alternating Current Stimulation (HD θ-tACS) of the Anterior Cingulate and Medial Prefrontal Cortex

2021 ◽  
Vol 15 ◽  
Author(s):  
Monika Klírová ◽  
Veronika Voráčková ◽  
Jiří Horáček ◽  
Pavel Mohr ◽  
Juraj Jonáš ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Inhibitory Control ◽  
Alternating Current ◽  
Stroop Test ◽  
Anterior Cingulate ◽  
Stop Signal Task ◽  
Control Performance ◽  
High Definition ◽  
Transcranial Alternating Current Stimulation

Increased frontal midline theta activity generated by the anterior cingulate cortex (ACC) is induced by conflict processing in the medial frontal cortex (MFC). There is evidence that theta band transcranial alternating current stimulation (θ-tACS) modulates ACC function and alters inhibitory control performance during neuromodulation. Multi-electric (256 electrodes) high definition θ-tACS (HD θ-tACS) using computational modeling based on individual MRI allows precise neuromodulation targeting of the ACC via the medial prefrontal cortex (mPFC), and optimizes the required current density with a minimum impact on the rest of the brain. We therefore tested whether the individualized electrode montage of HD θ-tACS with the current flow targeted to the mPFC-ACC compared with a fixed montage (non-individualized) induces a higher post-modulatory effect on inhibitory control. Twenty healthy subjects were randomly assigned to a sequence of three HD θ-tACS conditions (individualized mPFC-ACC targeting; non-individualized MFC targeting; and a sham) in a double-blind cross-over study. Changes in the Visual Simon Task, Stop Signal Task, CPT III, and Stroop test were assessed before and after each session. Compared with non-individualized θ-tACS, the individualized HD θ-tACS significantly increased the number of interference words and the interference score in the Stroop test. The changes in the non-verbal cognitive tests did not induce a parallel effect. This is the first study to examine the influence of individualized HD θ-tACS targeted to the ACC on inhibitory control performance. The proposed algorithm represents a well-tolerated method that helps to improve the specificity of neuromodulation targeting of the ACC.

scholarly journals Inhibitory control and problematic Internet-pornography use – The important balancing role of the insula

2020 ◽  
Vol 9 (1) ◽  
pp. 58-70
Author(s):  
Stephanie Antons ◽  
Brand Matthias
Keyword(s):  
Image Processing ◽  
Inhibitory Control ◽  
Symptom Severity ◽  
Inferior Frontal Gyrus ◽  
Dual Process ◽  
Stop Signal Task ◽  
Addictive Behaviors ◽  
Control Performance ◽  
Internet Pornography

Abstract Background and aims Diminished control over a specific behavior is a core characteristic in addictive behaviors such as problematic Internet-pornography (IP) use. First studies suggest that a hyperactivity of the impulsive system is one reason for impulsive behaviors in the context of problematic IP use. The tripartite-process theory of addiction explains neurocognitive mechanisms beyond common dual-process theories in addictive behaviors. However, the role of the reflective and interoceptive system is still unresolved. Methods The study comprised a stop-signal task (SST) including neutral and pornographic images during fMRI and questionnaires to investigate associations between symptoms of problematic IP use, craving, and neural activity of the impulsive, reflective, and interoceptive system. We examined 28 heterosexual males with varying symptom severity of problematic IP use. Results Data indicates that individuals with more symptoms of problematic IP use showed better performance in the SST which was linked to decreased insula and inferior frontal gyrus activity during pornographic image processing. An increase in craving was associated with lower activity of the ventral striatum during pornographic image processing. The interoceptive system showed varying effects. Increased insula activity during inhibitory control and decreased activity during pornographic image processing were associated with higher inhibitory control performance. Discussion and Conclusion Effects of tolerance and motivational aspects may explain the better inhibitory control performance in individuals with higher symptom severity which was associated with differential activity of the interoceptive and reflective system. Diminished control over IP use presumably results from the interaction between the impulsive, reflective, and interoceptive systems.

scholarly journals Evaluation of a Modified High-Definition Electrode Montage for Transcranial Alternating Current Stimulation (tACS) of Pre-Central Areas

2016 ◽  
Vol 9 (5) ◽  
pp. 700-704 ◽  
Author(s):  
Kirstin-Friederike Heise ◽  
Nick Kortzorg ◽  
Guilherme Bicalho Saturnino ◽  
Hakuei Fujiyama ◽  
Koen Cuypers ◽  
...  
Keyword(s):  
Alternating Current ◽  
High Definition ◽  
Transcranial Alternating Current Stimulation

scholarly journals Neural mechanisms of economic commitment in the human medial prefrontal cortex

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Konstantinos Tsetsos ◽  
Valentin Wyart ◽  
S Paul Shorkey ◽  
Christopher Summerfield
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Neural Mechanisms ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Financial Return ◽  
Economic Decisions ◽  
Decision Biases ◽  
Stimulus Value ◽  
Over Time

Neurobiologists have studied decisions by offering successive, independent choices between goods or gambles. However, choices often have lasting consequences, as when investing in a house or choosing a partner. Here, humans decided whether to commit (by acceptance or rejection) to prospects that provided sustained financial return. BOLD signals in the rostral medial prefrontal cortex (rmPFC) encoded stimulus value only when acceptance or rejection was deferred into the future, suggesting a role in integrating value signals over time. By contrast, the dorsal anterior cingulate cortex (dACC) encoded stimulus value only when participants rejected (or deferred accepting) a prospect. dACC BOLD signals reflected two decision biases–to defer commitments to later, and to weight potential losses more heavily than gains–that (paradoxically) maximised reward in this task. These findings offer fresh insights into the pressures that shape economic decisions, and the computation of value in the medial prefrontal cortex.

scholarly journals Altered heartbeat perception sensitivity associated with brain structural alterations in generalised anxiety disorder

2020 ◽  
Vol 33 (1) ◽  
pp. e100057 ◽  
Author(s):  
Hui Li ◽  
Bin Zhang ◽  
Qiang Hu ◽  
Lanlan Zhang ◽  
Yi Jin ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Anxiety Disorder ◽  
Anterior Cingulate Cortex ◽  
Medial Prefrontal Cortex ◽  
Grey Matter ◽  
Anterior Cingulate ◽  
Grey Matter Volume ◽  
Generalised Anxiety Disorder ◽  
Matter Volume ◽  
Heartbeat Perception

BackgroundPalpitation is a common complaint in generalised anxiety disorder (GAD). Brain imaging studies have investigated the neural mechanism of heartbeat perception in healthy volunteers. This study explored the neuroanatomical differences of altered heartbeat perception in patients with GAD using structural MRI.AimsBased on the strong somatic-interoceptive symptoms in GAD, we explored the regional structural brain abnormalities involved in heartbeat perception in patients with GAD.MethodsThis study was applied to the a priori regions using neuroanatomical theories of heartbeat perception, including the insula, anterior cingulate cortex, supplementary motor area and prefrontal cortex. A total of 19 patients with GAD and 19 healthy control subjects were enrolled. We used the FMRIB Software Library voxel-based morphometry software for estimating the grey matter volume of these regions of interest and analysed the correlation between heartbeat perception sensitivity and the volume of abnormal grey matter.ResultsPatients with GAD showed a significantly decreased volume of grey matter in their left medial prefrontal cortex, right orbital frontal cortex and anterior cingulate cortex. The grey matter volume of the left medial prefrontal cortex negatively correlated with heartbeat perception sensitivity in patients with GAD.ConclusionsIt should be the first study that shows heartbeat perception is associated with brain structure in GAD. Our findings suggest that the frontal region may play an important role in aberrant heartbeat perception processing in patients with GAD, and this may be an underlying mechanism resulting in the abnormal cardiovascular complaints in GAD. This is hypothesised as a ‘top-down’ deficiency, especially in the medial prefrontal cortex. This will provide the foundation for a more targeted region for neuromodulation intervention in the future.

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