Neural signals steer. The walking policy handles balance.
Downloading brain and robot…
Fourteen joint targets from the trained walking policy.
Drag to rotate · scroll to zoom · slice through the tissue to reveal the interior
Walking policy: left/right activity in antennal-lobe projection neurons steers; descending activity supplies forward drive. Smell is measured through the graph. Clearing scent removes that drive after the neural activity settles. MicroDuck’s trained policy supplies balance and gait.
Direct motors: twenty-eight fixed groups of descending neurons form fourteen opposing pairs. Their filtered activity differences set fourteen servo-position targets around the standing pose. The ONNX policy is completely bypassed. There is no scripted gait or balance controller: the duck can twitch, shift, or fall. Switching modes resets its body.
The graph retains 139,255 neurons and 2,698,236 directed connections from FlyBrain’s FlyWire-derived data. Gain is reduced to prevent background activity from saturating the movement decoder. Neural wiring stays fixed and untrained. The sensory interface and output mappings are engineering choices.
Anatomy: the tissue surface is a real FlyWire brain mesh. Each point uses a supplied coordinate for that neuron, linked by its original ID. Brightness shows its actual modeled spikes. These points are representative locations, not complete neuron branches or measured living-brain activity. Slice reveals the interior.
Inside the head: the inset combines the real MicroDuck head mesh with an illustrative fly, enlarged for visibility, and four brain electrodes. The electrodes connect to the head’s inside ceiling. The cutaway slowly rotates, and the fly makes small wing and leg movements. Pause stops the animation; dragging still lets you inspect it. Its green link responds to modeled descending activity. The banana is a visual source of fermentation scent, a natural attractant for fruit flies; this model still uses the same artificial smell inputs. Reaching the banana collects it, then another appears after a brief pause. Removing it manually cancels that respawn.
Scent is an artificial bilateral sensor; no target coordinates enter the motor decoder. Turning responds to scent, but this does not establish biological behavior or reliable navigation.
This resets the neural state. Sensory neurons still fire, but downstream movement signals should go silent. “Brain connected” gates output while leaving the brain running.
Robot model and walking policy: Pollen Robotics. See methods and licenses.