Meeting Abstract
How do sensorimotor computations change in relation to modulations in the salience of sensory information? To address this question, we examined how the refuge-tracking response of the weakly electric glass knifefish Eigenmannia virescens changes as a function of electrosensory and visual salience. Our system commanded a refuge to follow a pseudo-random input signal and measured the resulting fish motion. Electrosensory salience was modulated by changing the conductivity of the water, and visual salience was modulated with a light switch. In the light, electrosensory salience had little effect on the input-output response, but in the dark, the phase lag of the tracking response increased with increasing conductivity (i.e., decreasing electrosensory salience). This suggests that the nervous system takes more time to integrate sensory information for control in a manner similar to luminance-dependent tracking in crepuscular moths (Sponberg et al., 2015). We fit these data using the McRuer Crossover Model, a parsimonious model developed to explain visuomotor control in humans. This model captured the salience-dependent change in phase lag with a commensurate change in the time delay parameter with negligible change to other model parameters. More experiments are needed to test the generality of these results.
