Tutorials


Advanced fMRI analyses have the potential to answer questions that mainstream methods cannot. BrainIAK aims to integrate these cutting-edge techniques into a single, accessible Python environment. To help users get started, we have created the following set of tutorials based on courses taught at Princeton and Yale Universities.

Preview

The tutorials below are designed to be consumed in sequence, but are modular and can be approached in any order (for more details, see the tutorials preprint). We provide recommendations to scaffold on users’ knowledge and skills, though even advanced users have reported benefiting from the full sequence. All of the notebooks are paired with data that have been preprocessed and are ready for use. Our resources page has helpful links on learning the basics of fMRI preprocessing.

First steps

If you are new to fMRI analysis, Python and/or machine learning:
  1. Setup: Get familiar with running a Jupyter notebook.
  2. Data handling: Load, reshape and normalize fMRI data in Python.

General machine learning

If you are familiar with fMRI analysis and Python, but have limited experience with machine learning:
  1. Classification: Run a classifier using leave-one-run-out cross-validation.
  2. Dimensionality Reduction: Apply PCA and other feature selection techniques.
  3. Classifier Optimization: Use cross-validation to optimize classifier hyperparameters.

Specific advanced tools

If you are familiar with fMRI analysis, Python and machine learning:
  1. Representational Similarity Analysis: Compare pattern similarity for human and non-human data.
  2. Searchlight: Setup and run a parallelized searchlight analysis.
  3. Seed-Based Connectivity: Define seeds and compute functional connectivity.
  4. Full Correlation Matrix Analysis: Perform an unbiased, seedless, full brain correlation analysis.
  5. Inter-Subject Correlation: Calculate correlations between subjects to reduce noise and estimate task-relevant signals.
  6. Shared Response Modeling: Use a common stimulus to project subjects into a shared functional space.
  7. Event Segmentation with Hidden Markov Models: Find latent event states in continuous, naturalistic stimuli.
  8. Real-Time fMRI: Handle and classify fMRI data generated in real-time.

Getting started

Some guidance for how to access / install the tutorials:

Detailed installation instructions

If you have any questions or problems, you can ask the folks in our Gitter chat or file an issue on GitHub.

Google Colaboratory

To only run the tutorials, you can use Google Colaboratory. You only need a web browser. No other installation is necessary. Follow the Colab instructions below. A few notes:

  1. There is a setup that needs to be completed (install brainiak and dependencies, and download data each time you run the tutorials. This can take between 5-15 minutes depending on the size of the dataset you download.
  2. Google Colab has a session timeout of 12 hours (with browser kept open). After 12 hours, you will need to redo the setup to run a tutorial. If the browser window is closed it will reset in 90 minutes.
  3. When running tutorials that cover Inter-Subject Correlations and the Shared Response Model (which use the Pieman dataset), you should reduce the number of subjects to 5. This will ensure that the data do not exceed the available memory.

If you want to save your code, you can save a copy of the notebook to Google Drive (accessible from the File menu in Colab).

Instructions

  • In Google Chrome go to: colab.research.google.com
  • In the window click on the Github tab (May need to select File->Open_Notebook for window to appear)

    alt

  • Enter ‘brainiak tutorials’ in the search box
  • Choose branch master (should be already selected by default)
  • Click on notebook tutorials/colab-env-setup.ipynb (you may need to scroll down)

    alt

  • Run cell “Install Brainiak and code dependencies”
  • A window will pop-up. Uncheck “Reset all runtimes before running”

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  • After the installation is complete run cell “Git-clone helper files for tutorials”
  • There are many download data cells. Pick only the data cell for your tutorial and run that cell. This may take a few minutes depending on the size of the data.
  • You are now ready to execute your notebook.
  • Open a new tab in Chrome and go to colab.research.google.com
  • Click on File->Open Notebook
  • In the window click on the Github tab
  • Enter “brainiak tutorials” in the search box
  • Pick the notebook that you need to run
  • Execute cell
  • A window will pop-up. Uncheck “Reset all runtimes before running”
  • Continue running notebook

Docker on laptop/desktop (MacOS)

  • Install Docker.
  • Resize memory for Docker. click: Docker on Menu Bar -> Preferences -> Advanced

    alt

    The more memory and swap space you can assign, the better. We have tested with 5GB of memory. The default setting of 2GB is too little to load large datasets. Also, increase the swap space to approximately 4-5GB. If your available space is less than 4GB, set the swap space to whatever you have available.

  • Download data for the tutorial
    • Create a folder under Downloads: brainiak_datasets
    • Unzip the data file and move it to this folder brainiak_datasets
  • Shutdown all running Jupyter terminals on your machine to avoid port conflicts
  • Open Terminal
  • Install the BrainIAK Docker by running this command
  • docker run -it -p 8899:8899 -v ~/Downloads/brainiak_datasets:/root/brainiak_datasets --name tutorials brainiak/tutorials
  • Installation Completed 😊

Note the port that you need to connect to the browser: 8899

Running Tutorials

  • Open a browser on your machine
  • Go to http://localhost:8899 (it’s the port after the -p above. Ignore any other port info)
  • You will be prompted for a “Password/Login Token”.
  • Copy the token as shown below

    Login Token

  • Open tutorials and run.

    Login Token

Docker on laptop (Windows)

  • Install Docker using Linux containers
  • Resize memory for Docker use. We have tested with 5-7GB of memory on Windows. The default setting of 2GB is too small to load large datasets. Increase the swap space to approximately 4-5GB. If your available space is less than 4GB, set the swap space to whatever you have available.
  • Download data for the tutorial
    • Unzip data and move it to Downloads/brainiak_datasets
  • Share C drive in Docker (instructions here)
  • Run Docker after replacing USERNAME with your Windows user name:

    docker run -it -p 8899:8899 -v C:/Users/USERNAME/downloads/brainiak_datasets:/root/brainiak_datasets --name tutorials brainiak/tutorials

Running Tutorials

  • Open a browser on your machine
  • Go to http://localhost:8899 (it’s the port after the -p above. Ignore any other port info)
  • You will be prompted for a “Password/Login Token”.
  • Copy the token as shown below

    Login Token

  • Open tutorials and run.

    Login Token

Conda on laptop (MacOS)

This option is supported for OSX and Linux. For Windows, please use Colab or Docker.

  • Check if you have conda installed already. Run conda in your terminal
  • If you have conda installed, proceed to the next step. Only do these steps if you do not have conda installed.
  • Install brainiak-tutorial conda package:

    conda create --name mybrainiak python=3.6

    conda activate mybrainiak or source activate mybrainiak

    mv ~/.condarc ~/.condarc.bak

    conda install -c pni -c defaults -c conda-forge brainiak_tutorials

  • In any folder (e.g., cd my_code) that you would like to store the tutorials run:

    git clone https://github.com/brainiak/brainiak-tutorials.git

  • Download data for the tutorial
  • Unzip the data file and move it into this folder ~/Downloads/brainiak_datasets
  • The screen shot shows a sample of the data directories for different tutorials

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Running Tutorials

  • In Terminal, cd my_code/brainiak_tutorials/tutorials
  • Check your environment
    • Using a text editor, check file setup_environment.sh for CONDA_ENV=mybrainiak
    • Set configuration='local'
  • In Terminal execute: ./run_jupyter.sh
  • In the browser, you will see a Jupyter window with a list of files
  • Open (click) utils.py
  • A new tab opens up with this file.
  • Update variable data_path to ~/Downloads/brainiak_datasets/
  • Change

    data_path = os.path.join(os.path.expanduser('~'), 'brainiak_datasets') to

    data_path = os.path.join(os.path.expanduser('~'), 'Downloads', 'brainiak_datasets')

  • If you move the dataset to any other path, you will need to modify the data_path to reflect the new location of the dataset.
  • Go back to the “Home” tab with the list of files
  • Open assigned tutorial.
  • Execute it.

Conda on server

  • Connect to server using Terminal
  • Install Miniconda with Python 3

    Example install commands:

    wget https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh

    bash Miniconda3-latest-Linux-x86_64.sh

    or run the following command to load pre-installed anaconda:

    Here is an example: module load anacondapy/5.3.1

  • Create a Conda environment

    conda create -n mybrainiak

    source activate mybrainiak or conda activate mybrainiak

  • Ensure that your .condarc is not interfering:

    mv ~/.condarc ~/.condarc.bak

  • Install brainiak-tutorial conda package

    conda install -c pni -c defaults -c conda-forge brainiak_tutorials

  • Download data for the tutorial

    wget --no-check-certificate -r -O 'datasets.zip' 'https://docs.google.com/uc?export=download&id=1ZglrmkYw8isBAfsL53n9JgHEucmrnm4E'

    unzip datasets.zip

  • Change data directory path
  • Move data to ~/brainiak_datasets/

  • In the terminal clone the tutorial repo:

    git clone https://github.com/brainiak/brainiak-tutorials.git

Running Tutorials

cd brainiak_tutorials/tutorials

  • Check your environment
    • Check file setup_environment.sh for CONDA_ENV=mybrainiak
    • Check configuration='server'
  • Launch Jupyter on server (steps and screen shots here for Jupyter on server)

    ./run_jupyter_remote_server.sh

    Enter token printed by script when asked for token/password on the jupyter web page

Conda on cluster

  • Install Miniconda with Python 3
  • Install brainiak-tutorial conda package

    conda install -c pni -c defaults -c conda-forge brainiak_tutorials

  • Download data for the tutorial
  • Move data to ~/brainiak_datasets/
  • In terminal, clone the tutorial repository
    • git clone https://github.com/brainiak/brainiak-tutorials.git
  • Check directory path in utils.py
    • If you change the download location, you will have to update data_path in utils.py
  • Check your environment
    • Check file setup_environment.sh for CONDA_ENV=mybrainiak
    • Set configuration='cluster'

Running Tutorials

  • Check your environment
    • Check file setup_environment.sh for CONDA_ENV=mybrainiak
    • Check configuration='cluster'
  • Launch Jupyter on cluster (steps and screen shots here for Jupyter on server)

    cd brainiak-tutorials/tutorials

    ./run_jupyter_remote_server.sh (Verify all SLURM parameters for your cluster)

Conda on cluster (admin)

This installation is typically performed by cluster administrators. As a user, you only need to update the modules used, and the path to the data directory. You are expected to have knowledge of SLURM parameters, for your cluster, to launch the Jupyter notebooks and run batch jobs. Your cluster administrator can help you with setting the SLURM parameters.

Administrator tasks

  • Open Terminal
  • Login to the cluster
  • Install brainiak-tutorial conda package

    conda install -c pni -c defaults -c conda-forge brainiak_tutorials

  • Download tutorial data brainiak_datasets.zip

    wget --no-check-certificate -r -O 'datasets.zip' 'https://docs.google.com/uc?export=download&id=1ZglrmkYw8isBAfsL53n9JgHEucmrnm4E'

    unzip datasets.zip

  • Move data to a central location where everyone can access.
  • Provide this data path location to all users.

User tasks

  • Get directory path to data from administrator.
  • Verify SLURM parameters with administrator.
  • Open Terminal
  • Login to the cluster
  • Check access to the repo online: https://github.com/brainiak/brainiak-tutorials.git
  • In the terminal, clone the tutorial repo: git clone https://github.com/brainiak/brainiak-tutorials.git

    cd brainiak-tutorials/tutorials/

Run tutorials Edit file setup_environment.sh and add the correct module. Your cluster administrator should provide the names of the module(s) (e.g., module load pyger/0.8) to load.

  • Comment out CONDA_NAME=mybrainiak
  • Set configuration='cluster’
  • Make the run_jupyter_remote_server.sh script executable

    chmod 711 run_jupyter_remote_server.sh

  • Initiate a remote Jupyter connection to the server - screenshots here: Jupyter on server
  • Run the script: ./run_jupyter_remote_server.sh
  • Open utils.py
  • Update data_path in utils.py to the path location of the brainiak_datasets folder.
  • You will need to update this line:

    data_path = os.path.join(os.path.expanduser('~'), 'brainiak_datasets') with the correct path.

  • Run tutorials

Data downloads

These datasets are pre-processed and ready to use. They have been condensed to keep the file size small, by reducing the number of subjects from the original studies. Each tutorial is paired with a dataset as listed below. The file brainiak_datasets.zip contains the data for all the tutorials, and in unzipped form uses 18GB of space. If you wish to download data for specific tutorials, use the list below to find the correct dataset to download and use. Note that Colab has its own data download mechanism (see Colab install instructions).

The above data urls point to google drive for faster downloads. The doi reference for these tutorial datasets is https://doi.org/10.5281/zenodo.2598755.

Resources

We have compiled a list of useful resources that cover the basics of GitHUB, Python, fMRI, and Machine Learning here.

Open Source License

Like BrainIAK itself, these tutorials are open-sourced as a service to the field and can be freely used, modified, and shared. They are licensed under the Apache License, Version 2.0. If you find them helpful in your research or re-use code they contain, you might consider citing:

Kumar, M., Ellis, C. T., Lu, Q., Zhang, H., Capota, M., Willke, T. L., Ramadge, P. J., Turk-Browne, N.B., Norman, K. (2019). BrainIAK tutorials: user-friendly learning materials for advanced fMRI analysis. Retrieved from https://osf.io/j4sbc.