PNAS Journal just published my study “Motion Parallax in electric sensing”, which is a joint project with Jacob Engelmann and Federico Pedraja (Active Sensing Group) at Bielefeld University (in Germany) and John Lewis (Comparative Physiology Group) at the University of Ottawa (Canada) on the use of sensory flow for sensing in context of distance estimation.
In this study we provide the first direct experimental evidence for the long discussed hypothesis that weakly electric fish use cues from the spatiotemporal dynamic sensory flow to analyze their surroundings.
This adds substantial significance to a series of studies (both our own and from various other labs) regarding the benefits of sensory flow analysis for sensing in general and establishes weakly electric fish amongst the “champion animals” to study this phenomenon. In our experiments we combine experimentally measured and computationally modelled data (BEM & FEM) of the electric field geometry to predict the perceptual abilities. Using this we set up a behavioral test: while using the fishes motor behavior in a moving shuttle setup (see picture – courtesy of J. Engelmann) as a readout for their sensory performance, we manipulated specific parameters in the dynamic domain of electrosensory input experimentally. By moving the shuttle walls at differing speeds we were able to manipulate the fishes behavior in a predicted manner thereby showing that they use cues from the arising electrosensory flow (i.e. dynamic sensory input) to adjust their behavioral output. All of the above was shown for species from both independently evolved taxa, the African Mormyrids (we tested the elephant nose Gnathonemus petersii AND the South American Gymnotiforms (we tested both the glass knifefish Eigenmannia virescens as well as the blackghost knifefisch Apteronotus Albifrons) .