05 / Continual learning

Plastic Signal Garden

Watch a recurrent agent and its fast weights as the beacon rule changes.

Saved checkpoint replay · arena and neural telemetry

05 / Checkpoint replay

Inside Signal Garden.

The white agent chooses actions as the rewarded beacon changes. The panels show recorded activity from the same model step.

AgentRewarded beaconHazard

Recurrent activity

24 sampled units

Fast weights

Memory slots

Plastic norm—
Goals collected0
RuleInitial

Loading saved episode…

Recorded from garden_200k_v2 / best checkpoint. Fixed seeds 118–120; 320 steps each. Colors indicate activity magnitude, not new connections.

Activity through the episode

Plastic weight norm across the episode. The vertical mark follows playback; the orange line marks the rule switch.

The project

Three timescales of state

The agent has slow learned recurrent weights, fast Hebbian weights updated at each step, and twelve gated memory slots. A cue selects a rewarded beacon; the cue-to-beacon mapping changes once during each episode.

Observations & lessons

What the replay reveals

Neural activity and plastic weights remain active when the rule changes. In these three fixed replays, the selected checkpoint collects zero goals. The training run also finishes with negative episode reward. The next useful test is whether plasticity improves navigation over the same recurrent model with fast weights disabled.

Recorded training

The 200,000-step run.

Signal Garden episode reward, plastic norm, and firing over training steps
Top: episode reward. Middle: plastic weight norm. Bottom: firing activity. Resets follow the batched episode schedule.