Replace with clean markdown card
Browse files
README.md
CHANGED
|
@@ -13,13 +13,12 @@ tags:
|
|
| 13 |
|
| 14 |
# EEGSym
|
| 15 |
|
| 16 |
-
EEGSym from Pérez-Velasco et al (2022) .
|
| 17 |
|
| 18 |
-
> **Architecture-only repository.**
|
| 19 |
> `braindecode.models.EEGSym` class. **No pretrained weights are
|
| 20 |
-
> distributed here**
|
| 21 |
-
> data
|
| 22 |
-
> separately.
|
| 23 |
|
| 24 |
## Quick start
|
| 25 |
|
|
@@ -38,239 +37,44 @@ model = EEGSym(
|
|
| 38 |
)
|
| 39 |
```
|
| 40 |
|
| 41 |
-
The signal-shape arguments above are
|
| 42 |
-
|
| 43 |
|
| 44 |
## Documentation
|
| 45 |
-
|
| 46 |
-
-
|
| 47 |
-
<https://braindecode.org/stable/generated/braindecode.models.EEGSym.html>
|
| 48 |
-
- Interactive browser with live instantiation:
|
| 49 |
<https://huggingface.co/spaces/braindecode/model-explorer>
|
| 50 |
- Source on GitHub: <https://github.com/braindecode/braindecode/blob/master/braindecode/models/eegsym.py#L16>
|
| 51 |
|
| 52 |
-
## Architecture description
|
| 53 |
-
|
| 54 |
-
The block below is the rendered class docstring (parameters,
|
| 55 |
-
references, architecture figure where available).
|
| 56 |
-
|
| 57 |
-
<div class='bd-doc'><main>
|
| 58 |
-
<p>EEGSym from Pérez-Velasco et al (2022) [eegsym2022]_.</p>
|
| 59 |
-
<span style="display:inline-block;padding:2px 8px;border-radius:4px;background:#5cb85c;color:white;font-size:11px;font-weight:600;margin-right:4px;">Convolution</span>
|
| 60 |
-
|
| 61 |
-
:bdg-dark-line:`Channel`
|
| 62 |
-
|
| 63 |
-
.. figure:: ../../docs/_static/model/eegsym.png
|
| 64 |
-
:align: center
|
| 65 |
-
:alt: EEGSym Architecture
|
| 66 |
-
|
| 67 |
-
|
| 68 |
-
The **EEGSym** is a novel Convolutional Neural Network (CNN) architecture designed for
|
| 69 |
-
Motor Imagery (MI) based Brain-Computer Interfaces (BCIs), primarily aimed at
|
| 70 |
-
**overcoming inter-subject variability** and significantly **reducing BCI inefficiency**
|
| 71 |
-
[eegsym2022]_.
|
| 72 |
-
|
| 73 |
-
The architecture integrates advances from Deep Learning (DL), complemented by
|
| 74 |
-
Transfer Learning (TL) techniques and Data Augmentation (DA), to achieve strong
|
| 75 |
-
performance in inter-subject MI classification [eegsym2022]_.
|
| 76 |
-
|
| 77 |
-
.. rubric:: Architectural Overview
|
| 78 |
-
|
| 79 |
-
EEGSym systematically incorporates three core features:
|
| 80 |
-
|
| 81 |
-
#. **Inception Modules** for multi-scale temporal analysis [eegsym2022]_.
|
| 82 |
-
#. **Residual Connections** maintain spatio-temporal signal structure and
|
| 83 |
-
enable deeper feature extraction [eegsym2022]_.
|
| 84 |
-
#. A **Siamese-network design** exploits the inherent symmetry of the brain
|
| 85 |
-
across the mid-sagittal plane [eegsym2022]_.
|
| 86 |
-
|
| 87 |
-
.. rubric:: Macro Components
|
| 88 |
-
|
| 89 |
-
- `EEGSym.symmetric_division` **(Input Processing)**
|
| 90 |
-
- *Operations.* The input is virtually split into left, right, and middle channels.
|
| 91 |
-
Middle (central) channels are duplicated and concatenated to both left
|
| 92 |
-
and right lateralized electrodes to form the two hemisphere inputs [eegsym2022]_.
|
| 93 |
-
- *Role.* Prepares the data for the siamese-network approach,
|
| 94 |
-
reducing the number of parameters in the spatial filters
|
| 95 |
-
for the tempospatial analysis stage [eegsym2022]_.
|
| 96 |
-
|
| 97 |
-
- `EEGSym.inception_block` **(Tempospatial Analysis - Temporal Feature Extraction)**
|
| 98 |
-
- *Operations.* Uses :class:`_InceptionBlock` modules, which apply parallel
|
| 99 |
-
temporal convolutions with different kernel sizes (scales) [eegsym2022]_.
|
| 100 |
-
This is followed by concatenation, residual connections, and average
|
| 101 |
-
pooling for temporal dimensionality reduction [eegsym2022]_.
|
| 102 |
-
- *Role.* Captures detailed temporal relationships in the architecture,
|
| 103 |
-
similarly to :class:`~braindecode.models.eeginception_mi.EEGInceptionMI`
|
| 104 |
-
[eeginception2020]_. The first block uses large temporal kernels
|
| 105 |
-
(e.g., 500 ms, 250 ms, 125 ms) [eegsym2022]_.
|
| 106 |
-
|
| 107 |
-
- `EEGSym.residual_blocks` **(Tempospatial Analysis - Spatial Feature Extraction)**
|
| 108 |
-
- *Operations.* Composed of multiple :class:`_ResidualBlock` modules (typically three instances)
|
| 109 |
-
[eegsym2022]_. Each block applies temporal convolution, pooling, and a spatial analysis layer
|
| 110 |
-
(convolution or grouped convolution) [eegsym2022]_.
|
| 111 |
-
- *Role.* Enhances spatial feature extraction by incorporating residual
|
| 112 |
-
connections across all CNN stages, which helps maintain the spatio-temporal
|
| 113 |
-
structure of the signal through deeper layers [eegsym2022]_.
|
| 114 |
-
|
| 115 |
-
- `EEGSym.channel_merging` **(Hemisphere Merging)**
|
| 116 |
-
- *Operations.* The :class:`_ChannelMergingBlock` reduces the spatial dimensionality
|
| 117 |
-
(Z and C) to 1, performing two residual convolutions followed by a final grouped
|
| 118 |
-
convolution that merges the feature information from the two hemispheres [eegsym2022]_.
|
| 119 |
-
- *Role.* Extracts complex relationships between channels of both hemispheres as part of the
|
| 120 |
-
symmetry exploitation [eegsym2022]_.
|
| 121 |
-
|
| 122 |
-
- `EEGSym.temporal_merging` **(Temporal Collapse)**
|
| 123 |
-
- *Operations.* The :class:`_TemporalMergingBlock` uses residual convolution
|
| 124 |
-
followed by grouped convolution to reduce the temporal dimension (S) to 1 [eegsym2022]_.
|
| 125 |
-
- *Role.* Final step of temporal aggregation before the output module [eegsym2022]_.
|
| 126 |
-
|
| 127 |
-
- `EEGSym.output_blocks` **(Output Processing)**
|
| 128 |
-
- *Operations.* The :class:`_OutputBlock` applies four residual convolution iterations
|
| 129 |
-
(1x1x1 convolutions) followed by flattening [eegsym2022]_.
|
| 130 |
-
- *Role.* Final feature refinement through residual connections before the
|
| 131 |
-
fully connected classification layer [eegsym2022]_.
|
| 132 |
-
|
| 133 |
-
.. rubric:: How the information is encoded temporally, spatially, and spectrally
|
| 134 |
-
|
| 135 |
-
* **Temporal.**
|
| 136 |
-
Temporal features are extracted across multiple scales in the inception modules
|
| 137 |
-
using different temporal convolution kernel sizes (e.g., corresponding to
|
| 138 |
-
500 ms, 250 ms, and 125 ms windows for a 128 Hz sampling rate), very similar to [eeginception2020]_.
|
| 139 |
-
Subsequent pooling operations and residual blocks continue to reduce the temporal dimension
|
| 140 |
-
[eegsym2022]_.
|
| 141 |
-
|
| 142 |
-
* **Spatial.**
|
| 143 |
-
|
| 144 |
-
Spatial features are extracted via two main mechanisms:
|
| 145 |
-
|
| 146 |
-
- (1) The **siamese-network design** implicitly introduces brain symmetry by treating the two hemispheres
|
| 147 |
-
equally during feature extraction [eegsym2022]_.
|
| 148 |
-
- (2) **Residual connections** are utilized in the Tempospatial Analysis stage to enhance the extraction of
|
| 149 |
-
spatial correlations between electrodes [eegsym2022]_.
|
| 150 |
-
|
| 151 |
-
* **Spectral.**
|
| 152 |
-
Spectral information is implicitly captured by the varying kernel sizes of the temporal convolutions
|
| 153 |
-
in the inception modules [eegsym2022]_. These kernels filter the signal across different temporal windows,
|
| 154 |
-
corresponding to different frequency characteristics.
|
| 155 |
-
|
| 156 |
-
Notes
|
| 157 |
-
-----
|
| 158 |
-
* EEGSym achieved competitive accuracies across five large MI datasets [eegsym2022]_.
|
| 159 |
-
* The model maintained high accuracy using a reduced set of electrodes (8 or 16 channels)
|
| 160 |
-
[eegsym2022]_.
|
| 161 |
-
* This is PyTorch implementation of the EEGSym model of the TensorFlow original [eegsym2022code]_.
|
| 162 |
-
|
| 163 |
-
Parameters
|
| 164 |
-
----------
|
| 165 |
-
filters_per_branch : int, optional
|
| 166 |
-
Number of filters in each inception branch. Should be a multiple of 8.
|
| 167 |
-
Default is 12 [eegsym2022]_.
|
| 168 |
-
scales_time : tuple of int, optional
|
| 169 |
-
Temporal scales (in milliseconds) for the temporal convolutions in the first
|
| 170 |
-
inception module. Default is (500, 250, 125) [eegsym2022]_.
|
| 171 |
-
drop_prob : float, optional
|
| 172 |
-
Dropout probability. Default is 0.25 [eegsym2022]_.
|
| 173 |
-
activation : type[nn.Module], optional
|
| 174 |
-
Activation function class to use. Default is :class:`nn.ELU` [eegsym2022]_.
|
| 175 |
-
spatial_resnet_repetitions : int, optional
|
| 176 |
-
Number of repetitions of the spatial analysis operations at each step.
|
| 177 |
-
Default is 5 [eegsym2022]_.
|
| 178 |
-
left_right_chs : list of tuple of str, optional
|
| 179 |
-
List of tuples pairing left and right hemisphere channel names,
|
| 180 |
-
e.g., ``[('C3', 'C4'), ('FC5', 'FC6')]``. If not provided, channels
|
| 181 |
-
are automatically split into left/right hemispheres using
|
| 182 |
-
:func:`~braindecode.datautil.channel_utils.division_channels_idx` and
|
| 183 |
-
:func:`~braindecode.datautil.channel_utils.match_hemisphere_chans`.
|
| 184 |
-
Must be provided together with ``middle_chs`` [eegsym2022]_.
|
| 185 |
-
middle_chs : list of str, optional
|
| 186 |
-
List of midline (central) channel names that lie on the mid-sagittal plane,
|
| 187 |
-
e.g., ``['FZ', 'CZ', 'PZ']``. These channels are duplicated and concatenated
|
| 188 |
-
to both hemispheres. If not provided, channels are automatically identified
|
| 189 |
-
using :func:`~braindecode.datautil.channel_utils.division_channels_idx`.
|
| 190 |
-
Must be provided together with ``left_right_chs`` [eegsym2022]_.
|
| 191 |
-
|
| 192 |
-
References
|
| 193 |
-
----------
|
| 194 |
-
.. [eegsym2022] Pérez-Velasco, S., Santamaría-Vázquez, E., Martínez-Cagigal, V.,
|
| 195 |
-
Marcos-Martínez, D., & Hornero, R. (2022). EEGSym: Overcoming inter-subject
|
| 196 |
-
variability in motor imagery based BCIs with deep learning. IEEE Transactions
|
| 197 |
-
on Neural Systems and Rehabilitation Engineering, 30, 1766-1775.
|
| 198 |
-
.. [eegsym2022code] Pérez-Velasco, S., EEGSym source code.
|
| 199 |
-
https://github.com/Serpeve/EEGSym
|
| 200 |
-
.. [eeginception2020] Santamaría-Vázquez, E., Martínez-Cagigal, V.,
|
| 201 |
-
Vaquerizo-Villar, F., & Hornero, R. (2020). EEG-Inception: A novel deep
|
| 202 |
-
convolutional neural network for assistive ERP-based brain-computer interfaces.
|
| 203 |
-
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 28, 2773-2782.
|
| 204 |
-
|
| 205 |
-
.. rubric:: Hugging Face Hub integration
|
| 206 |
-
|
| 207 |
-
When the optional ``huggingface_hub`` package is installed, all models
|
| 208 |
-
automatically gain the ability to be pushed to and loaded from the
|
| 209 |
-
Hugging Face Hub. Install with::
|
| 210 |
-
|
| 211 |
-
pip install braindecode[hub]
|
| 212 |
-
|
| 213 |
-
**Pushing a model to the Hub:**
|
| 214 |
-
|
| 215 |
-
.. code::
|
| 216 |
-
from braindecode.models import EEGSym
|
| 217 |
-
|
| 218 |
-
# Train your model
|
| 219 |
-
model = EEGSym(n_chans=22, n_outputs=4, n_times=1000)
|
| 220 |
-
# ... training code ...
|
| 221 |
-
|
| 222 |
-
# Push to the Hub
|
| 223 |
-
model.push_to_hub(
|
| 224 |
-
repo_id="username/my-eegsym-model",
|
| 225 |
-
commit_message="Initial model upload",
|
| 226 |
-
)
|
| 227 |
-
|
| 228 |
-
**Loading a model from the Hub:**
|
| 229 |
-
|
| 230 |
-
.. code::
|
| 231 |
-
from braindecode.models import EEGSym
|
| 232 |
-
|
| 233 |
-
# Load pretrained model
|
| 234 |
-
model = EEGSym.from_pretrained("username/my-eegsym-model")
|
| 235 |
-
|
| 236 |
-
# Load with a different number of outputs (head is rebuilt automatically)
|
| 237 |
-
model = EEGSym.from_pretrained("username/my-eegsym-model", n_outputs=4)
|
| 238 |
-
|
| 239 |
-
**Extracting features and replacing the head:**
|
| 240 |
|
| 241 |
-
|
| 242 |
-
import torch
|
| 243 |
|
| 244 |
-
|
| 245 |
-
# Extract encoder features (consistent dict across all models)
|
| 246 |
-
out = model(x, return_features=True)
|
| 247 |
-
features = out["features"]
|
| 248 |
|
| 249 |
-
# Replace the classification head
|
| 250 |
-
model.reset_head(n_outputs=10)
|
| 251 |
|
| 252 |
-
|
| 253 |
|
| 254 |
-
|
| 255 |
-
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 256 |
|
| 257 |
-
config = model.get_config() # all __init__ params
|
| 258 |
-
with open("config.json", "w") as f:
|
| 259 |
-
json.dump(config, f)
|
| 260 |
|
| 261 |
-
|
| 262 |
|
| 263 |
-
|
| 264 |
-
|
| 265 |
-
|
| 266 |
|
| 267 |
-
See :ref:`load-pretrained-models` for a complete tutorial.</main>
|
| 268 |
-
</div>
|
| 269 |
|
| 270 |
## Citation
|
| 271 |
|
| 272 |
-
|
| 273 |
-
*References* section above) and braindecode:
|
| 274 |
|
| 275 |
```bibtex
|
| 276 |
@article{aristimunha2025braindecode,
|
|
|
|
| 13 |
|
| 14 |
# EEGSym
|
| 15 |
|
| 16 |
+
EEGSym from Pérez-Velasco et al (2022) [eegsym2022].
|
| 17 |
|
| 18 |
+
> **Architecture-only repository.** Documents the
|
| 19 |
> `braindecode.models.EEGSym` class. **No pretrained weights are
|
| 20 |
+
> distributed here.** Instantiate the model and train it on your own
|
| 21 |
+
> data.
|
|
|
|
| 22 |
|
| 23 |
## Quick start
|
| 24 |
|
|
|
|
| 37 |
)
|
| 38 |
```
|
| 39 |
|
| 40 |
+
The signal-shape arguments above are illustrative defaults — adjust to
|
| 41 |
+
match your recording.
|
| 42 |
|
| 43 |
## Documentation
|
| 44 |
+
- Full API reference: <https://braindecode.org/stable/generated/braindecode.models.EEGSym.html>
|
| 45 |
+
- Interactive browser (live instantiation, parameter counts):
|
|
|
|
|
|
|
| 46 |
<https://huggingface.co/spaces/braindecode/model-explorer>
|
| 47 |
- Source on GitHub: <https://github.com/braindecode/braindecode/blob/master/braindecode/models/eegsym.py#L16>
|
| 48 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| 49 |
|
| 50 |
+
## Architecture
|
|
|
|
| 51 |
|
| 52 |
+

|
|
|
|
|
|
|
|
|
|
| 53 |
|
|
|
|
|
|
|
| 54 |
|
| 55 |
+
## Parameters
|
| 56 |
|
| 57 |
+
| Parameter | Type | Description |
|
| 58 |
+
|---|---|---|
|
| 59 |
+
| `filters_per_branch` | int, optional | Number of filters in each inception branch. Should be a multiple of 8. Default is 12 [eegsym2022]. |
|
| 60 |
+
| `scales_time` | tuple of int, optional | Temporal scales (in milliseconds) for the temporal convolutions in the first inception module. Default is (500, 250, 125) [eegsym2022]. |
|
| 61 |
+
| `drop_prob` | float, optional | Dropout probability. Default is 0.25 [eegsym2022]. |
|
| 62 |
+
| `activation` | type[nn.Module], optional | Activation function class to use. Default is :class:`nn.ELU` [eegsym2022]. |
|
| 63 |
+
| `spatial_resnet_repetitions` | int, optional | Number of repetitions of the spatial analysis operations at each step. Default is 5 [eegsym2022]. |
|
| 64 |
+
| `left_right_chs` | list of tuple of str, optional | List of tuples pairing left and right hemisphere channel names, e.g., `[('C3', 'C4'), ('FC5', 'FC6')]`. If not provided, channels are automatically split into left/right hemispheres using :func:`~braindecode.datautil.channel_utils.division_channels_idx` and :func:`~braindecode.datautil.channel_utils.match_hemisphere_chans`. Must be provided together with `middle_chs` [eegsym2022]. |
|
| 65 |
+
| `middle_chs` | list of str, optional | List of midline (central) channel names that lie on the mid-sagittal plane, e.g., `['FZ', 'CZ', 'PZ']`. These channels are duplicated and concatenated to both hemispheres. If not provided, channels are automatically identified using :func:`~braindecode.datautil.channel_utils.division_channels_idx`. Must be provided together with `left_right_chs` [eegsym2022]. |
|
| 66 |
|
|
|
|
|
|
|
|
|
|
| 67 |
|
| 68 |
+
## References
|
| 69 |
|
| 70 |
+
1. Pérez-Velasco, S., Santamaría-Vázquez, E., Martínez-Cagigal, V., Marcos-Martínez, D., & Hornero, R. (2022). EEGSym: Overcoming inter-subject variability in motor imagery based BCIs with deep learning. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 30, 1766-1775.
|
| 71 |
+
2. Pérez-Velasco, S., EEGSym source code. https://github.com/Serpeve/EEGSym
|
| 72 |
+
3. Santamaría-Vázquez, E., Martínez-Cagigal, V., Vaquerizo-Villar, F., & Hornero, R. (2020). EEG-Inception: A novel deep convolutional neural network for assistive ERP-based brain-computer interfaces. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 28, 2773-2782.
|
| 73 |
|
|
|
|
|
|
|
| 74 |
|
| 75 |
## Citation
|
| 76 |
|
| 77 |
+
Cite the original architecture paper (see *References* above) and braindecode:
|
|
|
|
| 78 |
|
| 79 |
```bibtex
|
| 80 |
@article{aristimunha2025braindecode,
|