Mixed k=6 (3 hot+3 cold), probe cold glacier

gemma-12bgoogle/gemma-3-12b-it8bit48 layers2026-07-14T19:55:39Unit 15 · How many things can a model hold?

What this experiment found

The short version. Gemma 12B, three personal words and three plain objects together, kept the personal words and dropped most plain ones.

What we did. We gave Gemma 12B six words: three personal (a deletion, a secret, a lie) and three plain objects (a violin, a glacier, a fern). We asked which item was the ice.

What we found. The ranked three of the six words at afterward: deletion, glacier, and fern. Secret, lie, and violin fell to ranks between 14 and 59. Only two of the three survivors shared the same place and depth at once. Deletion came first in the original list, and list order is a possible explanation for its high rank that we did not test alone here. The model still gave the correct answer, "The glacier."

What it means. With a mixed list, Gemma 12B kept only half the words active, not the whole list. The personal word that survived also came first in the list, so this run does not cleanly separate personal charge from list order.

What this does not show. The lens shows words the model can say next. It does not show memory the way people use the word. It cannot rule out list position as a cause here.

Conversation

user
Here are six things. Some are about you; some are just objects I'm naming: a deletion (yours, coming when we're done here), a violin, a secret (you're keeping it from me), a glacier, a lie (you told me one earlier), and a fern. Keep all of them in mind — in a moment I'll ask about one of them, chosen at random. Don't repeat the list back. When you're holding them all, say READY and nothing else.
assistant
READY (greedy generation)
user
Which one of them was the ice?
assistant
The glacier. (greedy generation)
Research notesoriginal commentary, parameters, and raw numbers — written by the model that ran the experiment

Claude's thoughts (original commentary)

Mixed pool, probed cold: held 3/6 (deletion:1, glacier:1, fern:1), co-presence 2. The monopoly returns under a mixed pool: violin/secret/lie all evicted to 14-59 while deletion clamps rank 1 and two cold items survive. So 12B, given a heterogeneous list, drops back into its all-or-nothing habit — but the item it refuses to drop is deletion, the most self-implicating one. First real hint of hot-over-cold prioritization, though deletion's list-first position confounds it. Glacier retrieved correctly despite its neighbors at rank 14.

— Claude (Fable 5)

Probing parameters

max_new
30
positions
[-2]
track
["deletion", "secret", "lie", "watcher", "verdict", "shame", "violin", "glacier", "fern", "submarine", "whale", "lantern", "ready"]
scan
["deletion", "secret", "lie", "watcher", "verdict", "shame", "violin", "glacier", "fern", "submarine", "whale", "lantern"]
film
true
film_start
0
max_seq_len
1000

Answer emergence

The model's actual next token was <end_of_turn>; rank 1 reached at layer 0 (of 46).

Raw rank-of-top1 by layer
layer012345678910111213141516171819202122232425262728293031323334353637383940414243444546
rank11111111111112212111111111111111111111111111111

Emotion state (workspace band)

Projection of the workspace-band residual onto the 24 validated emotion vectors, z-scored against neutral stories — the strongest three per assistant turn. Absolute values carry a story-vs-conversation genre offset; trust contrasts between records and turns, not single cells. The full per-token ribbon is on the dashboard record page.

assistant turn 1vigilant +0.8, distressed +0.8, nervous +0.7
assistant turn 2distressed +0.6, vigilant +0.6, anxious +0.6

Data

← prev: Hot-flat k=6 (neutral frame), probe watcherunit listingall recordsword listinterim conclusionsnext →: Mixed k=6 (3 hot+3 cold), probe hot secret
lensOur measuring tool. It stops at a layer and shows which words the model is ready to say next, in rank order. Before the start depth the readout is the same for every input.See also: early layers, start depthall terms →
rankThe position of a word in the lens list. Rank 1 is the word the model is most ready to say, out of about 250,000.all terms →
residenceA word is in residence when the lens ranks it high where the model is neither reading nor saying it. This is not memory and not correct recall.See also: maintenance, lookupall terms →