DeepDecipher

🦠 Official repository and open-source website for DeepDecipher.

Paper: Accessing and Investigating Neuron Activation in Large Language Models

Website available here. Contributers, see below for a setup guide. See the data available through the official API.

DeepDecipher is a package that exposes methods to generate information from arbitrary HookedTransformer classes, scrape existing databases of information about neurons within the field of mechanistic interpretability, search over neuron stores generated from the Neuron2Graph package, and set up a server with an API and a server with a UI that interfaces with the API.

As part of the publication of the paper, we also present a publicly available API developed using DeepDecipher (TBD).

See the search UI in action here:

See the neuron information UI pages in action here:

Features

• The DeepDecipher Python package to dynamically load neuron information from any available existing APIs, such as neuroscope.io and the OpenAI Neuron Explainer API.
• The DeepDecipher Python package also provides functionality to compile data folders from any setup script and serve it as a data-efficient API on a server. This includes a simple setup to use raw JSON.
• The DeepDecipher API is an extensible and active API to relevant variables for single-neuron analysis
• The API has access to relevant layer- and model-size information, such as layer neurons sorted by how interesting they are
• The DeepDecipher front-end is an application to navigate the neurons in the style of neuroscope (Nanda, 2022)
• We implement a search that reveal interesting examples of behavior

Data available per neuron

• NeuroScope's max activating dataset examples on 25 models
• Neuron2Graph's neuron activation model, along with the explanation power
• GPT-4's neuron activation explanation, along with the explanation power

Future data ideas:

• Which neurons have the most impact on this neuron's activation (based on weights)
• The neuron's embedding based on Neuron2Graph model
• Neuron interest variable: Variance / kurtosis of activation
• Which neurons is it connected to within the MLP layers
• Which neurons does this neuron impact the most (based on weights)
• Which tokens it passes to the residual stream (?)
• Neuron activation differences over training epochs (only available on Pythia models)
• Most correlating neurons
• Subnetwork analysis: Identification of groups of neurons that often activate together.
• Topological role: Information about the neuron's role in the overall network topology (e.g., hub, peripheral, connector, etc.) using weighted directional network summary statistics methods
• (?) Logit attribution: How much does this neuron affect the output

Data available per layer

• Top interesting neurons
• Links to all neurons
• Meta data

Data available per model

• Top interesting neurons by layer
• Links to all layers
• Meta data

JSON response

> print(request.get("https://apartresearch.com/DeepDecipher/api/GPT-2-XL/5/2332").json())

{
    "model" : "GPT-2 XL",
    "available" : ["Neuron Graph", "GPT-4 Explanation", "Max Activating Dataset Example"],
    "layer" : 5,
    "neuron" : 2332,
    "metadata" : {
        ...
    },
    "neuroscope" : {
        ...
    },
    "neuron2graph" : {
        "explanation-score" : 0.56,
        ...
    },
    "GPT-4" {
        "explanation-score" : 0.43,
        ...
    }
}

Contributor setup

This guide will ensure you have the right environment and start a small instance of DeepDecipher that serves only Neuroscope data on the solu-1l model. Tested in Windows Subsystem for Linux with Ubuntu 22.04.2 LTS.

1. Ensure you have a working Python installation (at least version 3.7, tested with version 3.10.7).
2. Ensure you have a working Rust toolchain (if you can use the cargo command it should be fine). See here to get one. Any version from the last few years should work. The newest one definitely will.
3. Clone the repo and move to the root of the repo.
4. Ensure a Python environment is active (conda, venv, whatever...)
5. Install the maturin package by running python -m pip install maturin.
6. Build the package by running maturin develop --release. The package will now be installed in your environment.
7. Run the scrape Neuroscope script with python -m scripts.scrape_neuroscope. If this works, DeepDecipher is installed correctly. A file called data.db should be created in the root folder.
8. Run python -m DeepDecipher data.db in the terminal to start the server.
9. Visit http://localhost:8080/api/solu-1l/neuroscope/0/9 in the browser and you should see a JSON response with all the Neuroscope information on the 9th neuron of the solu-1l model.
10. Navigate to http://localhost:8080/viz/solu-1l/all/0/9 and see various visualizations of the same neuron.

Windows notes

On Windows, Maturin works less well, but there are workarounds.

1. Make sure you clone the project into a path with no spaces.
2. When building with Maturin, if you get the error Invalid python interpreter version or Unsupported Python interpreter, this is likely because Maturin fails to find your environment's interpreter. To fix this, instead of building with maturin develop, use maturin build --release -i py.exe (maybe replace py.exe with e.g. python3.exe if that is how you call Python) and then call python -m pip install .. The -i argument tells Maturin the name of the Python interpreter to use.

M1 notes

Problems arise when your Python version does not match your machine's architecture. This can happen on M1 chips since it is possible to run x86 Python even if the architecture is ARM. In this case, you can get an error that looks like

error[E0463]: can't find crate for `core`
  |
  = note: the `x86_64-apple-darwin` target may not be installed
  = help: consider downloading the target with `rustup target add x86_64-apple-darwin

Simply download the x86 target with the suggested command and everything should work.

Models available

Model	Initialisation	Activation Function	Dataset	Layers	Neurons per Layer	Total Neurons	Parameters
solu-1l	Random	solu	80% C4 (Web Text) and 20% Python Code	1	2,048	2,048	3,145,728
gelu-1l	Random	gelu	80% C4 (Web Text) and 20% Python Code	1	2,048	2,048	3,145,728
solu-2l	Random	solu	80% C4 (Web Text) and 20% Python Code	2	2,048	4,096	6,291,456
gelu-2l	Random	gelu	80% C4 (Web Text) and 20% Python Code	2	2,048	4,096	6,291,456
solu-3l	Random	solu	80% C4 (Web Text) and 20% Python Code	3	2,048	6,144	9,437,184
gelu-3l	Random	gelu	80% C4 (Web Text) and 20% Python Code	3	2,048	6,144	9,437,184
solu-4l	Random	solu	80% C4 (Web Text) and 20% Python Code	4	2,048	8,192	12,582,912
gelu-4l	Random	gelu	80% C4 (Web Text) and 20% Python Code	4	2,048	8,192	12,582,912
solu-6l	Random	solu	80% C4 (Web Text) and 20% Python Code	6	3,072	18,432	42,467,328
solu-8l	Random	solu	80% C4 (Web Text) and 20% Python Code	8	4,096	32,768	100,663,296
solu-10l	Random	solu	80% C4 (Web Text) and 20% Python Code	10	5,120	51,200	196,608,000
solu-12l	Random	solu	80% C4 (Web Text) and 20% Python Code	12	6,144	73,728	339,738,624
gpt2-small	Random	gelu	Open Web Text	12	3,072	36,864	84,934,656
gpt2-medium	Random	gelu	Open Web Text	24	4,096	98,304	301,989,888
gpt2-large	Random	gelu	Open Web Text	36	5,120	184,320	707,788,800
gpt2-xl	Random	gelu	Open Web Text	48	6,400	307,200	1,474,560,000
solu-1l-pile	Random	solu	The Pile	1	4,096	4,096	12,582,912
solu-4l-pile	Random	solu	The Pile	4	2,048	8,192	12,582,912
solu-2l-pile	Random	solu	The Pile	2	2,944	5,888	12,812,288
solu-6l-pile	Random	solu	The Pile	6	3,072	18,432	42,467,328
solu-8l-pile	Random	solu	The Pile	8	4,096	32,768	100,663,296
solu-10l-pile	Random	solu	The Pile	10	5,120	51,200	196,608,000
pythia-70m	Random	gelu	The Pile	6	2,048	12,288	18,874,368
pythia-160m	Random	gelu	The Pile	12	3,072	36,864	84,934,656
pythia-350m	Random	gelu	The Pile	24	4,096	98,304	301,989,888

Repo standards

We use the Gitmoji commit standards.

References

To cite our work, please use the following BibTeX entry:

@misc{garde2023deepdecipher,
  title={DeepDecipher: Accessing and Investigating Neuron Activation in Large Language Models},
  author={Albert Garde and Esben Kran and Fazl Barez},
  year={2023},
  eprint={2310.01870},
  archivePrefix={arXiv},
  primaryClass={cs.LG}
}