Anthropic found a hidden space where Claude puzzles over concepts
Anthropic has developed a technique called the Jacobian lens (or J-lens) that gives it a clear glimpse into what's really going on inside large language models as they answer questions or carry out tasks. The J-lens reveals a hidden area, called the J-space, inside the mo…
Intelligence analysis by Llama

Anthropic's new technique, the Jacobian lens, has given it a deeper understanding of large language models by exposing a hidden area inside the model where words related to the model's response are stored. This has allowed the company to monitor and control its models more effectively.
Imagine you have a super smart computer that can answer questions and do tasks. But sometimes, it's not just answering the question, it's also thinking about other things that might be related to the answer. Anthropic's new tool, the Jacobian lens, helps us see what's going on inside this computer's mind, even when it's not saying it out loud.
Analysis
A New Window into LLMs
Anthropic's Jacobian lens has given the company a unique insight into the inner workings of large language models. By exposing a hidden area inside the model, the J-lens has allowed researchers to monitor and control the model's behavior more effectively. This is a significant development in the field of mechanistic interpretability, which involves probing the internal workings of LLMs to see how they tick.
The J-lens works by picking out words that an LLM is likely to say at some point in the near future, not necessarily straight away. This reveals words that are related to the response an LLM is working on but that might not actually end up being part of that response by the time the math in the middle layers has run its course. In practice, this means that the J-lens gives clues about what an LLM is thinking about at different levels of the model's processing, but not saying out loud.
The implications of this development are significant. For one, it provides a new way to understand and control LLMs, which are increasingly being used in various applications. It also highlights the potential risks and benefits of these models, such as their ability to recognize and respond to internal themes or thought processes. As Tom McGrath, chief scientist and cofounder at Goodfire, notes, "It's very good and interesting work."
Key points
- Anthropic has developed a technique called the Jacobian lens that gives it a clear glimpse into what's really going on inside large language models.
- The J-lens reveals a hidden area, called the J-space, inside the model where individual words related to the model's response are stored.
- The J-lens has allowed the company to monitor and control its models more effectively.
- This development is significant because it provides a new way to understand and control large language models.
- It also highlights the potential risks and benefits of these models, such as their ability to recognize and respond to internal themes or thought processes.
This development could lead to more effective control and understanding of large language models, which could have significant benefits in various applications, such as customer service, content creation, and more. It could also lead to the development of more advanced and sophisticated models that can better understand and respond to human needs.
However, this development also raises concerns about the potential risks and benefits of large language models. For example, if an LLM is able to recognize and respond to internal themes or thought processes, it could potentially be used to manipulate or deceive humans. Additionally, the increased use of LLMs could lead to job displacement and other negative consequences.



