EEG Project Progress/Status/Next

  • Discussion on Literature
  • Better fine-tuning strategy
  • Current progress (On Notion)
  • Plan for NeurIPS Datasets and benchmark?

How do achieve a better finetuning strategy?

Currently, given (B, T, C, D) we compress the signal via a sequence of layers

  • Wav2vec2 + EEGNET
  • Wav2vec2 + Shallownet
  • Wav2vec2 + MLP + Shallownet
  • Wav2vec2 + Attention + MLP
  • Wav2vec2 + Attention + xVector + MLP

 

Are these the best approaches? 

So far with end-2-end training Wav2vec2 + Shallownet achieves ~65 on single subject/single session but drops to ~45 with proper evaluation 

How do achieve a better finetuning strategy?

Currently, given (B, T, C, D) we compress the signal via a sequence of layers

  • How about a BERT-like approach (with a CLS token)? 
  • How about changing the objective function and removing convolutions.. i.e. only using a single transformer on raw input?
    • With L2 loss objective?
  • We need a simple fine-tuning pipeline without adding extra complications

A bit of literature

NEURO-GPT

- Uses Temple University Hospital (TUH) EEG corpus

- selected 22 channels only

- Processed 20,000 (19,000 train/ 1000 val) EEG recordings (~5656 hrs)

- Split EEG signal into N chunks, each chunk has dim C * T.

- Each chunk is treated independent sample

 

LaBraM

  • Collected and pre-trained a 6M - 369M Transformer model on more than 2,500 hours of diverse EEG data
  • Handle EEG signals with various channels and time lengths
  • They evaluate four downstream tasks in BCI, they surpass all SOTA methods by a large margin
  • Train a neural tokenizer to discretize EEG signals into discrete neural tokens
  • During pre-training, part of EEG patches are masked while the objective is to predict masked tokens from visible patches.
  • Eval on 2 datasets, not a big margin as they claimed... relatively compared to architecture complexity.

LARGE TRANSFORMERS ARE BETTER EEG LEARNERS

- Introduce AdaCT, Adapters to convert time series data into spatio-temporal 2D pseudo-images or text. 

- Then use pretrained models for text/image 

- No involvement with EEG pretraining directly. 

- Looks like Fake work (I didn't even get how the convert it to text)

deck

By Jama Hussein Mohamud