Visual Orientation Behaviour

The Goal: Understanding of the underpinnings of autonomous orientation; i.e. the central steps of visual information processing following pre-processing in the optic ganglia.

The Virtual-Reality Paradigm: A fly is monitored by an over-head video camera while walking on an elevated platform amidst a water-filled moat. Virtual objects can be shown on a cylindrical screen composed of nearly 6000 LEDs. The objects can be manipulated at will depending on the fly’s actions.


View into the virtual-reality paradigm



Distance Estimation: Flies judge distances to objects on the basis of parallax motion. In order to understand the underlying processing we study the factors that interfere with distance estimation.

Persistence of Orientation: Flies can continue the approach to a previously chosen object, even if that object disappears from sight. In the Detour Paradigm flies can be lured away from the direct path to the vanished object but nevertheless find their way. We recently located the short-term orientation memory in the brain structure "ellipsoid body" which is a constituent of the of the central complex. (Neuser et al. (2008) Analysis of a spatial orientation memory in Drosophila. Nature 453: 1244-47)

Abandoning an Object: Specific brain neuropils mediate the ability to give up on a previously chosen attractive object if it proves to be non-rewarding. The pathways are being analyzed.

Course-Stabilization in Rotatory Large-Field Motion: Walking flies follow rotatory large-field motion by circling in an attempt to stabilize their retinal image. We study course stabilization because this pathway causing circling and turning on the spot is partially different from that engaged during object fixation.

For further details see:
Schuster S, Strauss R Götz KG (2002) Virtual reality techniques resolve the visual cues used by fruit flies to evaluate object distances. Curr. Biol. 12, 1591-4