Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis

Recent studies show that the integrity of core perceptual and cognitive functions may be tested in a short time with Steady-State Visual Evoked Potentials (SSVEP) with low stimulation frequencies, between 1 and 10 Hz. Wearable EEG systems provide unique opportunities to test these brain functions on...

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Main Authors: Victor Javier Kartsch, Velu Prabhakar Kumaravel, Simone Benatti, Giorgio Vallortigara, Luca Benini, Elisabetta Farella, Marco Buiatti
Format: Article
Language:English
Published: MDPI AG 2022-12-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/22/24/9803
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author Victor Javier Kartsch
Velu Prabhakar Kumaravel
Simone Benatti
Giorgio Vallortigara
Luca Benini
Elisabetta Farella
Marco Buiatti
author_facet Victor Javier Kartsch
Velu Prabhakar Kumaravel
Simone Benatti
Giorgio Vallortigara
Luca Benini
Elisabetta Farella
Marco Buiatti
author_sort Victor Javier Kartsch
collection DOAJ
description Recent studies show that the integrity of core perceptual and cognitive functions may be tested in a short time with Steady-State Visual Evoked Potentials (SSVEP) with low stimulation frequencies, between 1 and 10 Hz. Wearable EEG systems provide unique opportunities to test these brain functions on diverse populations in out-of-the-lab conditions. However, they also pose significant challenges as the number of EEG channels is typically limited, and the recording conditions might induce high noise levels, particularly for low frequencies. Here we tested the performance of Normalized Canonical Correlation Analysis (NCCA), a frequency-normalized version of CCA, to quantify SSVEP from wearable EEG data with stimulation frequencies ranging from 1 to 10 Hz. We validated NCCA on data collected with an 8-channel wearable wireless EEG system based on BioWolf, a compact, ultra-light, ultra-low-power recording platform. The results show that NCCA correctly and rapidly detects SSVEP at the stimulation frequency within a few cycles of stimulation, even at the lowest frequency (4 s recordings are sufficient for a stimulation frequency of 1 Hz), outperforming a state-of-the-art normalized power spectral measure. Importantly, no preliminary artifact correction or channel selection was required. Potential applications of these results to research and clinical studies are discussed.
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spelling doaj.art-050895a8f811459691df92c57fc1f49b2023-11-24T17:55:35ZengMDPI AGSensors1424-82202022-12-012224980310.3390/s22249803Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation AnalysisVictor Javier Kartsch0Velu Prabhakar Kumaravel1Simone Benatti2Giorgio Vallortigara3Luca Benini4Elisabetta Farella5Marco Buiatti6Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi”, University of Bologna, 40136 Bologna, ItalyDigital Society Center, Fondazione Bruno Kessler, 38123 Trento, ItalyDepartment of Electrical, Electronic, and Information Engineering “Guglielmo Marconi”, University of Bologna, 40136 Bologna, ItalyCenter for Mind/Brain Sciences (CIMeC), University of Trento, 38068 Rovereto, ItalyDepartment of Electrical, Electronic, and Information Engineering “Guglielmo Marconi”, University of Bologna, 40136 Bologna, ItalyDigital Society Center, Fondazione Bruno Kessler, 38123 Trento, ItalyCenter for Mind/Brain Sciences (CIMeC), University of Trento, 38068 Rovereto, ItalyRecent studies show that the integrity of core perceptual and cognitive functions may be tested in a short time with Steady-State Visual Evoked Potentials (SSVEP) with low stimulation frequencies, between 1 and 10 Hz. Wearable EEG systems provide unique opportunities to test these brain functions on diverse populations in out-of-the-lab conditions. However, they also pose significant challenges as the number of EEG channels is typically limited, and the recording conditions might induce high noise levels, particularly for low frequencies. Here we tested the performance of Normalized Canonical Correlation Analysis (NCCA), a frequency-normalized version of CCA, to quantify SSVEP from wearable EEG data with stimulation frequencies ranging from 1 to 10 Hz. We validated NCCA on data collected with an 8-channel wearable wireless EEG system based on BioWolf, a compact, ultra-light, ultra-low-power recording platform. The results show that NCCA correctly and rapidly detects SSVEP at the stimulation frequency within a few cycles of stimulation, even at the lowest frequency (4 s recordings are sufficient for a stimulation frequency of 1 Hz), outperforming a state-of-the-art normalized power spectral measure. Importantly, no preliminary artifact correction or channel selection was required. Potential applications of these results to research and clinical studies are discussed.https://www.mdpi.com/1424-8220/22/24/9803SSVEPCCANCCAwearable EEGfrequency taggingdelta band
spellingShingle Victor Javier Kartsch
Velu Prabhakar Kumaravel
Simone Benatti
Giorgio Vallortigara
Luca Benini
Elisabetta Farella
Marco Buiatti
Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
Sensors
SSVEP
CCA
NCCA
wearable EEG
frequency tagging
delta band
title Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
title_full Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
title_fullStr Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
title_full_unstemmed Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
title_short Efficient Low-Frequency SSVEP Detection with Wearable EEG Using Normalized Canonical Correlation Analysis
title_sort efficient low frequency ssvep detection with wearable eeg using normalized canonical correlation analysis
topic SSVEP
CCA
NCCA
wearable EEG
frequency tagging
delta band
url https://www.mdpi.com/1424-8220/22/24/9803
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