Direct electrical stimulation of the premotor cortex shuts down awareness of voluntary actions

Abstract

A challenge for neuroscience is to understand the conscious and unconscious processes underlying construction of willed actions. We investigated the neural substrate of human motor awareness during awake brain surgery. In a first experiment, awake patients performed a voluntary hand motor task and verbally monitored their real-time performance, while different brain areas were transiently impaired by direct electrical stimulation (DES). In a second experiment, awake patients retrospectively reported their motor performance after DES. Based on anatomo-clinical evidence from motor awareness disorders following brain damage, the premotor cortex (PMC) was selected as a target area and the primary somatosensory cortex (S1) as a control area. In both experiments, DES on both PMC and S1 interrupted movement execution, but only DES on PMC dramatically altered the patients' motor awareness, making them unconscious of the motor arrest. These findings endorse PMC as a crucial hub in the anatomo-functional network of human motor awareness.

Targeting Primary Motor Cortex (M1) Functional Components in M1 Gliomas Enhances Safe Resection and Reveals M1 Plasticity Potentials

“…if Canada of USA, country; the results were downloaded onto Brainstorm (a MATLAB toolbox; Tadel, Baillet, Mosher, Pantazis, & Leahy, 2011), obtaining a 3D-MRI reconstruction of each patient MR with all the sites marked as a scout. This was co-registered in the NMI-space [9,22,23]. In "normal"-map patients, the subdivision of the cortical hand-knob region was designed (Figure 3) based on 10 stimulated sites (1,3,5,7,9 covering the anterior region; 2,4,6,8,10 covering the posterior region); in each M1 site the cMT (absolute value/mA) at HF-To5 and HF-To2 was normalized within the subject (Z-score) to allow for a comparison between the anterior and posterior regions with each paradigm [9,22,23].…”

“…This was co-registered in the NMI-space [9,22,23]. In "normal"-map patients, the subdivision of the cortical hand-knob region was designed (Figure 3) based on 10 stimulated sites (1,3,5,7,9 covering the anterior region; 2,4,6,8,10 covering the posterior region); in each M1 site the cMT (absolute value/mA) at HF-To5 and HF-To2 was normalized within the subject (Z-score) to allow for a comparison between the anterior and posterior regions with each paradigm [9,22,23]. In "distorted"-map patients, in the absence of an anterior and posterior subdivision, the highest and lowest cMT in each patient obtained with HF-To5 vs. HF-To2 were selected.…”

“…In "distorted"-map patients, in the absence of an anterior and posterior subdivision, the highest and lowest cMT in each patient obtained with HF-To5 vs. HF-To2 were selected. Values were normalized within the subject (Z-score) to assess the preservation, despite the subversion of the architecture of the two functional components [9,[22][23][24]. Figure 3.…”

Measures of agency

“…A small body of experimental literature suggests that there is a type of phenomenal feeling related to movement. These studies have used either direct electrical cortical stimulation during surgery in tumour or epilepsy patients ( Fried et al 1991 ; Desmurget et al , 2009 ; Fornia et al , 2020 ) or indirect cortical stimulation in healthy participants using TMS to induce experiences of movement without accompanying movements of the body ( Amassian et al 1989 ; Christensen et al , 2010 ). These experiments indicate that participants either experience a sensation of movement or they experience an urge to move a body part akin to a voluntary experience of moving a body part.…”

Asleep or awake motor mapping for resection of perirolandic glioma in the nondominant hemisphere? Development and validation of a multimodal score to tailor the surgical strategy

“…1,[18][19][20] For instance, apraxia could occur, in the absence of motor strength deficit, when a tumor located within 2 cm of the primary motor area is removed and the praxis network is not carefully tested intraoperatively with dedicated tasks. 14,21 Furthermore, it is still unknown which clinical or tumor imaging factors favor asleep versus awake motor mapping. In fact, no clear indication is available for patients with glioma in the nondominant hemisphere, and there is also a lack of general consensus on the intraoperative anesthesia mapping paradigm that provides the best oncological and functional outcomes when tailored to the clinical context.…”