Diagram of the experimental setup. Moths (1) were attached to the horizontal movement sensor (2) in front of a screen (3). Images were projected onto the screen via the objective (4) of an oscilloscope (5). Clicks emitted by the insects were recorded using an acoustic transducer (6). Signals from the sensory and acoustic transducer were fed into an analog-to-digital converter (7), which was connected to a computer (8). The computer drove a video adapter (9) to produce the control signals for the oscilloscope.