---
license: pddl
tags:
- eeg
- medical
- clinical
- classification
- parkinson
- pedaling
---
# Singh2020: EEG Parkinson's Classification Dataset with Pedaling Task
The Singh2020 dataset contains EEG recordings collected during a lower-limb pedaling task designed to assess motor control in individuals with Parkinson's disease (PD), with a particular focus on freezing of gait (FOG) symptoms. A total of 39 participants were included: 13 PD patients with FOG (PDFOG+), 13 PD patients without FOG (PDFOG-), and 13 demographically matched healthy controls.

Participants completed a lower-limb motor task in which they pedaled one rotation in response to a visual "GO" cue, designed to minimize fall risk and reduce EEG artifacts from movement. Each subject completed at least two blocks of either 30 or 50 trials, with PDFOG+ participants performing fewer trials due to symptom severity. A tri-axial accelerometer mounted on the ankle measured pedaling kinematics.

EEG was recorded using a 64-channel cap with a sampling rate of 500 Hz.
## Paper
Singh, A., Cole, R. C., Espinoza, A. I., Brown, D., Cavanagh, J. F., & Narayanan, N. S. (2020). **Frontal theta and beta oscillations during lower-limb movement in Parkinson’s disease**. _Clinical Neurophysiology_, 131(3), 694-702.

DISCLAIMER: We (DISCO) are NOT the owners or creators of this dataset, but we merely uploaded it here, to support our's ([EEG-Bench](https://github.com/ETH-DISCO/EEG-Bench)) and other's work on EEG benchmarking.
## Dataset Structure
- `raw_data/` contains the unprocessed recording EEG and accelerometer data.
- `processed_data/` contains pre- (`_Ped_Processed.mat`) and post-processed (`_ANALYZED.mat`) experiment data, produced from the `RAW_DATA/` using `Step1_EEG_Pedaling_PreProcess.m` and `Step2_EEG_Pedaling_PostProcess.m` scripts, respectively.
- `ALL_data_Modeling.csv` contains participant information, such as age and MOCA test scores.
- `scripts/` contains various scripts that can be used to reproduce the results from the paper.
- `ORIGINAL_README.txt`: the original README with perhaps some more helpful information.

### Filename Format
In `raw_data/`, a recording consists of 3 files:
- `[GROUP][PID].vhdr`: The header file with meta information
- `[GROUP][PID].eeg`: contains the EEG (and accelerometer) data
- `[GROUP][PID].vmrk`: contains event information

where GROUP is either `Control` or `PD` (Parkinson's Disease) and PID is the participant's ID (also used in `ALL_data_Modeling.csv`).

Similarly, in `processed_data/`,
- `[GROUP][PID]_Ped_Processed.mat` contains pre-processed data epoched around trials
- `[GROUP][PID]_ANALYZED.mat` contains the time-frequency analysis of the pre-processed data

where, again, GROUP is either `Control` or `PD` (Parkinson's Disease) and PID is the participant's ID.
### Reading RAW_DATA Files in Python
In python, the 3 files that make up a raw recording can be read via:
```python
import mne
raw = mne.io.read_raw_brainvision("path_to/[GROUP][PID].vhdr")
```
Now, `raw.get_data(units='uV')` yields a numpy array of shape `(#channels, time_len)` in micro-Volt units.

Some general info can be inspected with `raw.info`, such as the sampling rate (`raw.info["sfreq"]`).

The channel names (in their correct order) can be seen via `raw.ch_names`. Note that `X`, `Y` and `Z` denote the accelerometer X-, Y- and Z-axis outputs.

Events can be read with
```python
events_list, events_dict = mne.events_from_annotations(raw)
```
where `events_dict` contains the mapping of the original event types (where `"S  1"` stands for the black smaller circle "warning" cue, and `"S  2"` stands for the green bigger circle "GO" cue) to event IDs in `[1,2]`, the latter of which are used in `events_list`.

`events_list` is a list of events, ordered by time. Each entry `e = [timestamp, (not important), event ID]` consists of the time of the event onset `timestamp` that refers to the `time_len` dimension in the `raw.get_data()` EEG array, as well as the event-ID.

(See the `https://mne.tools/stable/generated/mne.io.Raw.html` documentation for more details.)

### Reading Processed Files in Python
In python, the `[GROUP][PID]_Ped_Processed.mat` files can be read e.g. with the `mat73` package (to read MATLAB v7.3 files in HDF5 format):
```python
import mat73
mat = mat73.loadmat("path_to/[GROUP][PID]_Ped_Processed.mat")
```
Then `mat` contains (among others) the following fields and subfields
- `EEG`
    - `data`: EEG data of shape `(#channels, trial_len, #trials)`. E.g. a recording of 50 trials/epochs with 59 channels, each trial having a duration of 4 seconds and a sampling rate of 500 Hz will have shape `(59, 2000, 50)`. Recall that here, trials were epoched from -1000ms to +3000ms around the "GO" cue event.
    - `event`: Contains a list of dictionaries, each entry (each event) having the following description:
        - `latency`: The onset of the event, measured as the index in the merged time-dimension `#trials x trial_len` (note `#trials` being the _outer_ and `trial_len` being the _inner_ array when merging).
        - `type`: The type of event. Here, only `"S  2"` (larger green circle "GO" cue) events are stored.
        - `TimeDiff`: The time in seconds that has passed between the `"S  1"` and the `"S  2"` cue.
    - `chanlocs`: A list of channel descriptors
    - `nbchan`: Number of channels
    - `trials`: Number of trials/epochs in this recording
    - `srate`: Sampling Rate (Hz)

Additionally, the field and `bad_chans` lists bad channels of this recording.

## License
By the original authors of this work, this work has been licensed under the PDDL v1.0 license (see LICENSE.txt).