I ran:
conda install -c brainiak -c defaults -c conda-forge brainiak

Error given:

Collecting package metadata (current_repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.
Collecting package metadata (repodata.json): done
Solving environment: failed with initial frozen solve. Retrying with flexible solve.

PackagesNotFoundError: The following packages are not available from current channels:

• brainiak

Current channels:

• https://conda.anaconda.org/brainiak/osx-arm64
• https://conda.anaconda.org/brainiak/noarch
• https://repo.anaconda.com/pkgs/main/osx-arm64
• https://repo.anaconda.com/pkgs/main/noarch
• https://repo.anaconda.com/pkgs/r/osx-arm64
• https://repo.anaconda.com/pkgs/r/noarch
• https://conda.anaconda.org/conda-forge/osx-arm64
• https://conda.anaconda.org/conda-forge/noarch

To search for alternate channels that may provide the conda package you're
looking for, navigate to

https://anaconda.org

and use the search bar at the top of the page.