Influence of the number of trials on evoked motor cortical activity in EEG recordings
Por:
Borras M, Romero S, Alonso-Lopez JF, Bachiller A, Serna LY, Migliorelli C and Mañanas MA
Publicada:
1 ago 2022
Ahead of Print:
26 ago 2022
Resumen:
Objective. Improvements in electroencephalography enable the study of the localization of active brain regions during motor tasks. Movement-related cortical potentials (MRCPs), and event-related desynchronization (ERD) and synchronization are the main motor-related cortical phenomena/neural correlates observed when a movement is elicited. When assessing neurological diseases, averaging techniques are commonly applied to characterize motor related processes better. In this case, a large number of trials is required to obtain a motor potential that is representative enough of the subject's condition. This study aimed to assess the effect of a limited number of trials on motor-related activity corresponding to different upper limb movements (elbow flexion/extension, pronation/supination and hand open/close). Approach. An open dataset consisting on 15 healthy subjects was used for the analysis. A Monte Carlo simulation approach was applied to analyse, in a robust way, different typical time- and frequency-domain features, topography, and low-resolution electromagnetic tomography. Main results. Grand average potentials, and topographic and tomographic maps showed few differences when using fewer trials, but shifts in the localization of motor-related activity were found for several individuals. MRCP and beta ERD features were more robust to a limited number of trials, yielding differences lower than 20% for cases with 50 trials or more. Strong correlations between features were obtained for subsets above 50 trials. However, the inter-subject variability increased as the number of trials decreased. The elbow flexion/extension movement showed a more robust performance for a limited number of trials, both in population and in individual-based analysis. Significance. Our findings suggested that 50 trials can be an appropriate number to obtain stable motor-related features in terms of differences in the averaged motor features, correlation, and changes in topography and tomography.
Filiaciones:
Borras M:
Eng. Sistemes. Automàtica i inf. ind., Universitat Politècnica de Catalunya, Campus Diagonal Sud. Edifici U. C. Pau Gargallo, 5. 08028 Barcelona, Barcelona, 08034, SPAIN
Romero S:
Automatic Control Department (ESAII), Universitat Politecnica de Catalunya, Barcelona, Barcelona, Catalunya, 08034, SPAIN
Alonso-Lopez JF:
Universitat Politècnica de Catalunya, Campus Diagonal Sud. Edifici U. C. Pau Gargallo, 5, Barcelona, Catalunya, 08034, SPAIN
Bachiller A:
Automatic Control Department, Universitat Politècnica de Catalunya, EDIFICI H, AVDA. DIAGONAL, 647, Office 4.26, Barcelona, Catalunya, 08034, SPAIN
Serna LY:
Eng. Sistemes. Automàtica i inf. ind., Universitat Politècnica de Catalunya, Campus Diagonal Sud. Edifici U. C. Pau Gargallo, 5. 08028 Barcelona, Barcelona, 08034, SPAIN
Migliorelli C:
Unit of Digital Health, Eurecat Centre Tecnològic de Catalunya, Av. Universitat Autònoma, 23 - 08290 Cerdanyola del Vallès (Barcelona), Barcelona, Catalunya, 08290, SPAIN
Mañanas MA:
Departamento de Ingeniería de Sistemas, Universitat Politècnica de Catalunya, Campus Diagonal Sud. Edifici U. C. Pau Gargallo, 5., Barcelona, Catalunya, 08034, SPAIN
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