Date of Award
Union College Only
Bachelor of Science
target, moving, second, trace, control, excitation
While previous research on target selective descending neurons (TSDNs) in the dragonfly has focused on single target responses, there have been no studies examining responses to multiple moving targets. In this study, we intracellularly recorded the responses of TSDNs in dragonflies of family Aeshnidae to single and paired targets presented in the visual field. The stimuli consisted of 52 black, circular targets arranged in a 13 x 13 target square projected onto a screen in front of the dragonfly. Target movements were presented in either the horizontal or vertical direction, chosen based on the preference of the TSDN’s receptive field. The paired targets stimulus used pairings of targets separated by 10°, 15 °, 20°, 30°, or 40° in the visual field. These targets were presented in the following four ways: two targets moving in parallel from side A to side B, two targets moving in parallel from side B to side A, one target moving toward side A and the other to side B, and vice-versa. The electrophysiological recordings were then analyzed using MatLab software and compared side-by-side. Two preferred targets led to inhibition, while two inhibitory signals combined to produce excitation. Attentional mechanisms were observed at further distances and receptive fields were shown to be much larger than previously thought.
Nguyen, Randy, "The Influence of a Second Object on the Responses of Target Selective Descending Neurons in the Dragonfly" (2016). Honors Theses. 192.