Response inhibition mechanisms are mediated via cortical and subcortical networks. At the cortical level, the superior frontal gyrus, including the supplementary motor area (SMA) and inferior frontal areas, is important. There is an ongoing debate about the functional roles of these structures during response inhibition as it is unclear whether these structures process different codes or contents of information during response inhibition. In the current study, we examined this question with a focus on theta frequency oscillations during response inhibition processes. We used a standard Go/Nogo task in a sample of human participants and combined different EEG signal decomposition methods with EEG beamforming approaches. The results suggest that stimulus coding during inhibitory control is attained by oscillations in the upper theta frequency band (∼7 Hz). In contrast, response selection codes during inhibitory control appear to be attained by the lower theta frequency band (∼4 Hz). Importantly, these different codes seem to be processed in distinct functional neuroanatomical structures. Although the SMA may process stimulus codes and response selection codes, the inferior frontal cortex may selectively process response selection codes during inhibitory control. Taken together, the results suggest that different entities within the functional neuroanatomical network associated with response inhibition mechanisms process different kinds of codes during inhibitory control. These codes seem to be reflected by different oscillations within the theta frequency band. Hum Brain Mapp 38:5681-5690, 2017. © 2017 Wiley-Liss, Inc.

• Keywords
• EEG, beamforming, inferior frontal cortex, inhibitory control, neural oscillations, signal decomposition, supplementary motor area,
• MeSH
• Adult MeSH
• Evoked Potentials MeSH
• Inhibition, Psychological * MeSH
• Humans MeSH
• Young Adult MeSH
• Motor Skills physiology   MeSH
• Neuropsychological Tests MeSH
• Signal Processing, Computer-Assisted MeSH
• Prefrontal Cortex physiology   MeSH
• Reaction Time MeSH
• Theta Rhythm * MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

We studied whether the cognitive event-related potentials (ERP) in the subthalamic nucleus (STN) are modified by the modulation of the inferior frontal cortex (IFC) and the dorsolateral prefrontal cortex (DLPFC) with repetitive transcranial magnetic stimulation (rTMS). Eighteen patients with Parkinson's disease who had been implanted with a deep brain stimulation (DBS) electrode were included in the study. The ERPs were recorded from the DBS electrode before and after the rTMS (1 Hz, 600 pulses) over either the right IFC (10 patients) or the right DLPFC (8 patients). The ERPs were generated by auditory stimuli. rTMS over the right IFC led to a shortening of ERP latencies from 277 +/- 14 ms (SD) to 252 +/- 19 ms in the standard protocol and from 296 +/- 17 ms to 270 +/- 20 ms in the protocol modified by a higher load of executive functions (both P < 0.01). The application of rTMS over the DLPFC and the sham stimulation over the IFC showed no significant changes. The shortening of ERP latency after rTMS over the right IFC reflected the increase in the speed of the cognitive process. The rTMS modulation of activity of the DLPFC did not influence the ERP. Connections (the IFC-STN hyperdirect pathway) with the cortex that bypass the BG-thalamocortical circuitries could explain the position of the STN in the processing of executive functions.

• MeSH
• Acoustic Stimulation MeSH
• Analysis of Variance MeSH
• Frontal Lobe physiopathology   MeSH
• Electroencephalography MeSH
• Evoked Potentials physiology   MeSH
• Executive Function physiology   MeSH
• Electrodes, Implanted MeSH
• Middle Aged MeSH
• Humans MeSH
• Brain Mapping MeSH
• Neural Pathways physiopathology   MeSH
• Subthalamic Nucleus physiopathology   MeSH
• Parkinson Disease physiopathology   MeSH
• Signal Processing, Computer-Assisted MeSH
• Psychomotor Performance physiology   MeSH
• Reaction Time MeSH
• Auditory Perception physiology   MeSH
• Transcranial Magnetic Stimulation methods   MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH