Armin Hinterwirth    

PhD research

I'm currently a fourth-year graduate student in biology at the University of Washington. My main research interest lies in how animals respond to cues from their environment & how they use this information to successfully navigate through space.

Moth flight control

I have recently finished building a flight arena for the large hawkmoth Manduca sexta, in which I can test how mechanosensory and visual inputs are integrated to provide a moth with a reliable flight control system. The setup is very much inspired by the Rock'n'Roll arena in Michael Dickinson's lab at Caltech. Working with Manduca allows me to expand the analysis to detailed wing kinematics and, most importantly, electrophysiological measurements.

Moths also show very strong abdominal responses, which might be used to initiate body rotations during flight. (Due to shifts in center of mass, like a hang-glider pilot.) Such abdominal steering responses are elicited both by pure visual, as well as pure mechanical rotations. Right now, I'm in the process of characterizing how the response strength of each modality depends on the frequency of rotation and how the responses of each modality are integrated by the moth's flight control system.

Merry-Moth-Go-Round™

At the heart of the experimental setup sits a modular LED display system that was developed by Michael Reiser in the Dickinson Lab. The LEDs wrap around a moth centered in the middle of the arena and allow me to present a multitude of visual stimuli to the animal. The display itself is mounted onto a ball bearing, so it can be rocked back and forth by a computer-controlled stepper motor. It was initially build to allow rotation in the pitch axis, but I am in the process of adding a hinge, so the whole assembly can be turned to look at the yaw axis as well.

Construction of the arena

The rotating arena is held by a stable 80/20 frame. I designed the geometry with Unix-based 3D rendering software that can be obtained for free (BRL-CAD).

The images below show a few stages of the arena's construction:

Schematic of my experimental setup

The schematic below shows a simplified view of the experimental setup. One personal computer is driving the LED display and records physical parameters of the stimuli, as well as behavioral and electrophysiological responses of the animal. The other PC is dedicated for capturing high-speed video.