We first study futility-induced passivity in larval zebrafish. We introduce 3M-Progress, a model-memory objective that compares an online world model with a frozen memory of normal action consequences, and train the agent using intrinsic motivation alone. When swim commands no longer move the visual world, the agent reproduces the active–passive cycling observed in zebrafish. Its latent dynamics also recapitulate the temporal structure of neural and glial activity in the biological circuit for passivity.

We then extend this perspective to walking Drosophila, whose articulated body and richer action repertoire provide a more complex embodied setting. A simulated fly on a spherical treadmill allows us to compare behavior and internal activity with biological experiments showing neural asymmetry before spontaneous turns. We evaluate whether the agent produces fly-like walking and turning behavior and whether its recurrent activity contains information about future turn direction before movement begins.

Finally, we ask whether this approach can extend to larger, more open-ended embodied environments that more closely resemble the settings in which human curiosity operates. Preliminary results reveal important limitations, suggesting that the underlying world-model agents must first learn reliable behavior in these environments before curiosity can be meaningfully evaluated.

Together, these projects treat world models as the substrate through which curiosity is expressed and assessed. They show that purpose-built models can reproduce biologically observed behavior and internal dynamics, while extending curiosity to richer settings depends on whether the underlying world-model agent can first learn the environment reliably.