Specialized parallel pathways for adaptive control of visual object pursuit

• Parallel pathways detect a visual object in the central versus peripheral visual field • The pathway for objects in the central visual field has adjustable gain • In this pathway, gain depends on the direction of object motion and running speed • This pathway is recruited by arousal and increases the vigor of visual pursuit Parallel pathways detect a visual object in the central versus peripheral visual field The pathway for objects in the central visual field has adjustable gain In this pathway, gain depends on the direction of object motion and running speed This pathway is recruited by arousal and increases the vigor of visual pursuit To pursue a moving visual object, the brain must continuously steer the object to the center of the visual field via feedback. The gain of this control loop is flexible, yet the biological mechanisms underlying such adaptive control are not well understood. Here, we show that adaptive control in the Drosophila pursuit system involves two parallel pathways. One detects objects in the periphery and steers them toward the center of the visual field. The other detects objects near the center of the visual field and steers them to the visual midline while also increasing forward velocity. This latter pathway is flexible: gain increases when the object is moving away from the midline and when the pursuer is running fast—situations that demand rapid steering—and this pathway is preferentially recruited during arousal. Our findings demonstrate how adaptive control can emerge from parallel sensory-motor pathways with specialized properties.