Multimodal dataset from the CMx7-MM Experiment

# Multimodal EEG-fNIRS-physio dataset during hierarchical cognitive-motor tasks

This repository contains a raw multimodal dataset acquired in healthy adults performing a hierarchy of cognitive, motor, and combined cognitive-motor tasks. Data include neurophysiological (EEG, fNIRS), physiological (ECG and EMG), behavioral (push-button, torque), and subjective measures (sleepiness and cognitive load ratings), organized according to the Brain Imaging Data Structure (BIDS).

The dataset is described in detail in a submitted data paper.

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## 1. Dataset overview

- **Participants**
- 30 right-handed healthy adults (12 males, 18 females)
- BIDS IDs: `sub-001` to `sub-030`
- One participant (`sub-008`) has incomplete sessions; see `participants.tsv` for details.

- **Sessions**
- Three recording sessions per participant: `ses-01`, `ses-02`, `ses-03`
- Approximate duration: 30 minutes per session (about 90 minutes total per participant)
- All sessions took place in a quiet, dimly lit room with participants seated in a Biodex chair.

- **Modalities**
- EEG (32 channels, 10-20 system)
- fNIRS (prefrontal and sensorimotor montages)
- ECG (Delsys Trigno)
- Biodex torque and kinematic measures
- Push-button responses
- Phenotypic / subjective measures (Karolinska Sleepiness Scale, cognitive load ratings, demographics, handedness)

- **Tasks (7 total)**
1. Mental arithmetic (MA)
2. N-back (NB, 2-back, auditory)
3. Motor imagery (MI)
4. Passive motor (Pass-Mot, Biodex-driven arm movement)
5. Active motor (Act-Mot, voluntary movement with Biodex)
6. N-back arithmetic (NB-MA, combined N-back and mental arithmetic)
7. Full task (NB-MA-Act-Mot, combined cognitive-motor condition)

All recordings shared here are **raw exports** from the acquisition systems with no offline preprocessing applied.

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## 2. Experimental paradigm

Each participant performed the seven tasks within each session. Tasks were presented in random order, with:

- Task duration: 3 minutes per task
- Inter-task rest: 30 seconds
- Stimuli: auditory digits (0-9) and beeps, delivered via MATLAB/Psychtoolbox

Brief task descriptions:

- **MA (Mental arithmetic)**
Auditory digits (0-9). On each trial, participants add or subtract numbers so that the result stays in the 0-9 range.
- 72 events per task
- Event duration: 1.5 s
- Inter-event interval: 2.5 s

- **NB (N-back, 2-back)**
Auditory digits (0-9). Participants press a button when the current digit matches the digit presented two trials earlier.
- 72 events total, 18 targets
- Event duration: 0.5 s
- Inter-event interval: 1.5 s

- **MI (Motor imagery)**
Participants imagine moving the right arm (no actual movement) when they hear a beep.
- 18 targets
- Inter-target interval: 10 � 3 s

- **Pass-Mot (Passive motor)**
The participant�s right arm is moved by the Biodex device (external and internal rotation, 60� range).
- Movement duration: 2 s
- 18 movements per task
- Inter-movement interval: 10 � 3 s

- **Act-Mot (Active motor)**
Participants actively move the robotic arm in response to beeps.
- 18 movements per task
- Inter-target interval: 10 � 3 s

- **NB-MA (N-back arithmetic)**
Participants press a button when the running sum of the last digits corresponds to the 2-back condition (combined N-back and arithmetic).
- 72 events total, 18 targets
- Event duration: 1.5 s
- Inter-event interval: 2.5 s

- **Full task (NB-MA-Act-Mot)**
Same cognitive demands as NB-MA, but participants move their arm (instead of pressing a button) when the NB-MA condition is met.
- 72 events total, 18 targets
- Event duration: 1.5 s
- Inter-event interval: 2.5 s

Subjective ratings:

- Karolinska Sleepiness Scale (KSS) before each session
- Mental load ratings after each task (9-point Likert and visual analogue scale)