# Multimodal EEG-fNIRS neurofeedback for motor imagery

Camille O Muller, Thomas Prampart, Elise Bannier, Isabelle Corouge, Pierre Maurel

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## To cite this version:

Camille O Muller, Thomas Prampart, Elise Bannier, Isabelle Corouge, Pierre Maurel. Multimodal EEG-fNIRS neurofeedback for motor imagery. CORTICO 2025 - Journées du COllectif pour la Recherche Transdisciplinaire sur les Interfaces Cerveau-Ordinateur, May 2025, Lyon, France. Unpublished, pp.1-1, 2025, 10.13140/RG.2.2.22347.71208. [https://hal.science/hal-05120564v1](https://hal.science/hal-05120564v1)

HAL Id: hal-05120564

[https://hal.science/hal-05120564v1](https://hal.science/hal-05120564v1)

Submitted on 20 Jun 2025

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# Multimodal EEG-fNIRS neurofeedback for motor imagery

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Camille O. Muller ¹, Thomas Prampart ², Elise Bannier ¹,³, Isabelle Corouge ¹, Pierre Maurel ¹

¹ Univ Rennes, Inria, CNRS, Inserm, Empenn ERL U1228, Rennes, France; ² Univ Rennes, Inria, CNRS, IRISA, Rennes, France; ³ CHU Rennes, Department of Radiology, Rennes

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camille.muller@irisa.fr

## Context

**Neurofeedback (NF)** enables self-regulation of brain activity through real-time feedback extracted from brain activity measures [1]. NF based on motor imagery (MI) is considered a trigger for brain plasticity, as it detects neural modulation to stimulate motor targets in the brain [2].

**Multimodal neuroimaging**, with electroencephalography (EEG) and **functional near-infrared spectroscopy** (fNIRS), which measure electrical and hemodynamic activity respectively, could enhance brain signal characterization and ultimately improve NF performance [3].

## Objective

Assess the potential of multimodal EEG-fNIRS NF in the context of motor imagery using a custom EEG-fNIRS-NF experimental platform.

## Study protocol

### Participants:

* 30 healthy right-handed volunteers

### NF session design:

* Calibration MI run without NF (left upper-limb MI task)

* 3 randomized conditions / 6 runs: 2 EEG-only, 2 fNIRS-only and 2 EEG-fNIRS based NF

* Block design for each run (10x 15 s rest and 15 s NF task)

### NF score:

* Computed from: **right primary motor cortex** activity (EEG channel C4, fNIRS channels S1-D1 and S2-D2, fig 2)

* Visual feedback: ball moving vertically upward on a 1D gauge

* Multimodal NF score: average of EEG and fNIRS scores

<figure><img src="image_5.png" /><figcaption>Figure 1. Experimental protocol design</figcaption></figure>

## Perspectives

With a potential to increase neuroplasticity, multimodal EEG-fNIRS-NF system could find applications in clinical contexts, particularly in motor rehabilitation, for example in post-stroke units [8].

## Experimental platform

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Homemade cap-layout **combining EEG** (ActiChamp, Brain Products) **and fNIRS** (NIRScout XP, NIRx) sensors specifically designed for our NF target

### Features and pre-processing

**EEG:** Alpha (8-13Hz) event-related desynchronization (%)

Reference (Fz)

BP filter (8-13Hz)

Spatial filter (Laplacian around C4)

Epoching

**fNIRS:** Oxyhemoglobin concentration variations (Δµmol)

Raw intensity → optical density

Short-channel correction

Optical density → hemoglobin state

BP filter (0.01-0.09Hz)

Epoching

<figure><img src="image_7.png" /><figcaption>Figure 2. Brain cap layout on the 10-10 international system.</figcaption></figure>

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**Application software:** receive and process real-time signals, calculate NF score and present the visual NF.

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First implementation of fNIRS-BCI in the OpenViBE software [4]. Code of the platform publicly available [5].

## Preliminary results - discussion

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### Operational experimental platform:

* Real-time signals processing with a dedicated software (OpenViBE)

* Joint recording of EEG and fNIRS, with less than 30 min of installation and good online quality of signals

* Successful NF in every condition for each subject

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### Study protocol:

* Preliminary results: **feeling of NF control** in favor of combined feedback

* Brain related activity **hypothesis**: presenting a visual multimodal EEG-fNIRS based NF will result in higher brain activity in the sensorimotor cortices [6][7]

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**Recruitment ongoing** (ending in June 2025).

## REFERENCES

[1] Hammond D.C., Journal of Neurotherapy, 2011. [2] Neuper C., Pfurtscheller G., BCI, 2009. [3] Perronnet L., et al., bioRxiv, 2020. [4] Renard Y., et al., Presence, 2010. [5] Muller C.O., et al., Plos One, in revision, 2025. [6] Fazli S., NeuroImage, 2012. [7] Buccino A.P., Plos One, 2016. [8] Le Franc S., Frontiers in Human Neurosciences, 2022.

The article

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Université de Rennes

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Inserm
La science pour la santé
From science to health

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