Feasibility and reproducibility of electroencephalography-based corticokinematic coherence

Abstract

Corticokinematic coherence (CKC) is the phase coupling between limb kinematics and cortical neurophysiological signals reflecting cortical processing of proprioceptive afference, and is reproducible when estimated with magnetoencephalography (MEG). However, feasibility and reproducibility of CKC based on electroencephalography (EEG) is still unclear and is the primary object of the present report. Thirteen healthy right-handed volunteers (7 females, 21.7 ± 4.3 years) participated two separate EEG sessions 12.6±1.3 months apart. Participants' dominant and non-dominant index finger was continuously moved at 3 Hz for 4 min separately using a pneumatic-movement actuator. Coherence was computed between finger acceleration and three derivations of EEG signals: (1) average reference, (2) bipolar derivations, and (3) surface Laplacian. CKC strength was defined as the peak coherence value at the movement frequency. Intraclass-correlation coefficient values (0.74-0.93) indicated excellent inter-session reproducibility for CKC strength for all derivations and moved fingers. CKC strength obtained with EEG was ~2 times lower compared to MEG but the values were positively correlated across the participants. CKC strength was significantly (p<0.01) higher for bipolar (session-1 0.19±0.09; session-2 0.20±0.10) and surface Laplacian (session-1 0.22±0.09; session-2 0.21±0.09) derivations than for the average reference (session 1 0.10±0.04; session 2, 0.11±0.05). We demonstrated that CKC is feasible and reproducible tool to monitor proprioception using EEG recordings, although the strength of CKC was twice lower for EEG compared to MEG. Laplacian and bipolar (CP3-C1/CP3-C3 and CP4-C2/C4-FC2) EEG derivation(s) are recommended for future research and clinical use of CKC method.

More comprehensive proprioceptive stimulation of the hand amplifies its cortical processing

“…The result was replicated in the source-level analysis which showed ~28% stronger CKC for the simultaneous stimulation. Our result extends previous studies that have stimulated the proprioceptors related to the index finger (Bourguignon et al, 2016;Piitulainen et al, 2015Piitulainen et al, , 2018bPiitulainen et al, , 2020. We showed that the coherent proprioceptive afference from all induced fingers sum up to the SM1 cortex proprioceptive processing.…”

“…As expected, the peak CKC locations were concentrated on the Rolandic SM1 cortex (within ~8 mm) replicating previous results obtained by proprioceptive stimulation of the index finger (Bourguignon et al, 2016;Piitulainen et al, 2020Piitulainen et al, , 2018bPiitulainen et al, , 2015. However, the exact spatial coordinates for CKC source have been reported previously only for passive index finger movements elicited by an experimenter (Piitulainen et al, 2013b), not by precise stimulator.…”

“…Corticokinematic coherence (CKC) quantifies the phase coupling between limb kinematics (e.g. hand acceleration or contractile force, Piitulainen et al, 2013a) and cortical neurophysiological signals measured with magnetoencephalography (MEG, Piitulainen et al, 2013b) or electroencephalography (EEG) in adults (Piitulainen et al, 2020) and even in infants (Smeds et al, 2017). CKC peaks at the movement frequency and its harmonics in the primary sensorimotor cortex (SM1) contralateral to the moving limb (Bourguignon et al, 2011;Jerbi et al, 2007).…”

“…Marty et al, 2019) or in healthy aging (Piitulainen et al, 2018b). Finally, CKC has shown to be a reproducible tool to follow cortical proprioception at group level both for MEG and EEG (Piitulainen et al, 2018a(Piitulainen et al, , 2020.…”

Attention directed to proprioceptive stimulation alters its cortical processing in the primary sensorimotor cortex

“…Cortical processing of proprioceptive afference (i.e., from the “movement sensors,” for review see (Proske & Gandevia, 2012) to the primary sensorimotor (SM1) cortex can be examined using precise computer controlled movement actuators, that is, proprioceptive stimulators, in magnetoencephalography (MEG; Alary et al., 2002; Lange et al., 2001; Piitulainen et al., 2015), electroencephalography (EEG; Desmedt & Ozaki, 1991; Mima et al., 1996; Piitulainen et al., 2020) or functional magnetic resonance imaging (MRI; Nurmi et al., 2018; Weiller et al., 1996). Corticokinematic coherence (CKC) can be used to quantify the coupling between oscillatory cortical activity measured with electrophysiological recordings (MEG or EEG) and limb kinematics ( e.g ., acceleration, force, etc.…”