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README.md
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- google-bert/bert-base-uncased
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---
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- google-bert/bert-base-uncased
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# Transformer-Based fMRI Encoder Model
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This repository contains a Transformer-based model trained on neuroimaging datasets to classify conditions like Autism Spectrum Disorder (ASD) and ADHD, and to analyze brain activity during movie-watching. The model combines fMRI data with demographic features (age and gender) for binary classification tasks. Below is a detailed explanation of the datasets, model architecture, and training process.
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## **Model Architecture**
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The model integrates multi-modal data and leverages a Transformer backbone for feature extraction. Below is a breakdown of its components:
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### **1. Inputs**
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- **fMRI ROI Data:** High-dimensional features representing brain activity.
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- **Age Data:** Numerical input passed through a Multi-Layer Perceptron (MLP).
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- **Gender Data:** Binary input (male/female) embedded into a dense representation.
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### **2. Transformer Backbone**
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- A pretrained Hugging Face Transformer (e.g., BERT) with:
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- Configurable number of attention heads, layers, and hidden size.
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- Dropout for regularization.
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- Dynamically adjusted hyperparameters using `AutoConfig`.
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### **3. Pooling Mechanisms**
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- Aggregates the Transformer’s sequence outputs into a single vector using:
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- **Mean Pooling:** Averages hidden states.
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- **Max Pooling:** Selects the maximum value for each feature.
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- **Attention Pooling:** Learns attention weights to emphasize important sequence elements.
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### **4. Output**
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- A fully connected layer maps the pooled output to a scalar value for binary classification.
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---
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## **Training Process**
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### **Key Details:**
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- **Loss Function:** Binary Cross Entropy with Logits (`BCEWithLogitsLoss`), with class imbalance handled using positive weights.
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- **Optimizer:** Ranger (combines RAdam and Lookahead for stable convergence).
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- **Learning Rate Scheduler:** Cosine Annealing for gradual learning rate reduction.
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- **Gradient Clipping:** Prevents exploding gradients with a clipping threshold of 1.0.
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- **Early Stopping:** Stops training after 250 epochs without validation loss improvement.
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### **Datasets Used:**
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1. **ABIDE:** Autism vs. control classification.
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2. **ADHD-200:** ADHD vs. control classification.
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3. **Pixar Movie Dataset (Nilearn):** Brain activity analysis during movie-watching.
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### **Output:**
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The model’s state dictionary is saved as `fmri_encoder_model.pth`.
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---
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## **How to Use This Model**
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