Intentional Control of Internal States in Gemma 3 27B

This research was done as my capstone project during ARBOx4.

Epistemic Status: I'm relatively sure the results I obtained and my interpretations are correct. I'm unsure if the effect would replicate in a different setting and how much it differs between models.

Summary

I replicated the Intentional Control of Internal States section of Anthropic's Emergent Introspective Awareness in Large Language Models (Lindsey, 2025) on Gemma 3 27B Instruct and found the same effect with smaller strength. When told to think about a concept while repeating an unrelated sentence, the model has a stronger internal representation of that concept than when it is told not to think about the same concept.
I extended the experiment with two additional ways of measuring internal representation: SAE latents and Natural Language Autoencoder (NLA) explanations of activations. In both cases, the effect is also present and much more visible.

Introduction

As part of their research on the introspection abilities of LLMs, Anthropic found that when explicitly prompted to think about a concept while writing an unrelated sentence, the concept has a stronger internal representation than when prompted not to think about it.

Figure 4 from Lindsey (2025): Claude Opus 4.1 shows a stronger internal representation of "aquariums" when told to think about it while writing an unrelated sentence than when told not to think about it.

The paper only reports results for Claude models. It has been shown that small models also have introspective abilities, but as far as I know, nobody had replicated the intentional-control experiment itself.
I reproduced it on Gemma 3 27B-it, and extended it by using SAEs (Gemma Scope 2) and an activation-decoder (NLA) as additional measurements of internal representations.

Methodology

I used the prompt templates, concepts and sentences from Anthropic's paper: 50 concept words, 50 neutral sentences, and 99[1]baseline words. The model is Gemma 3 27B-it in bf16; activations are the residual…