Additional analog signal input How to acquire analog data simultaneously to the tracking experiment. Plug-In: Simple Analog Input

The Scenario Weakly electric fish, such as the african mormyrid Gnathonemus petersii use “acitve electrolocation” to navigate. They emit electric signals (electric organ discharges, EOD) which generate an electrical field around their body. By sensing field distortions, the fish can detect objects and analyze their properties. In this experiment, the electrical organ discharges (EOD) of the fish are registered with four electrodes. At the same time the Simple Analog Input Plug-In of the Viewer poses the frequencies of the electrical impulses in relation to swimming velocity and object distance, while the animal is tracked. The experiments serve for more informations about object recognition principles of the animals.

The Setup A DV-camera is placed over an aquarium with homogeneous, illuminated undreground and transfers the visual signal over framegrabber card to the PC that runs the Viewer software. In addition, four cross wired electrodes derive the EOD, transform it via a window discriminator into rectangle pulses and send these over the audio channel of a sound card into the Viewer. Test variables are swimming velocity, EOD frequency and distance to the object.

	The "Simple Analog Input" Plug-In logs the EOD frequency of the fish and shows it as an XY diagram over time. Apart from frequency, swimSpeed and distance to a predifined zone are calculated and presented in a table. After finishing the experiment, the data table can be exported as a CSV file for further processing. Results taken so far indicate that EOD transmitting frequency and swimming velocity of Gnathonemus petersii correlates positively. Furthermore the fish seems to increase its EOD frequency the closer he moves to the object.
	Summary The results illustrate the possibilities and advantages of the automated tracking solution “Viewer” and in particular the "Simple Analog Input" Plug-In for understanding the relation between swimming velocity as well as object distance and EOD frequency of the African elephant nose fish.

	If you have general questions about the "Viewer" software, please don't hesitate to use the following E-mail address: viewer@biobserve.com

Copyright © 2001-2008, BIOBSERVE GmbH. All rights reserved. Legal Notes & Privacy Policy

European headquarter: BIOBSERVE GmbH • Koenigswinterer Str. 418 • 53227 Bonn • Germany Phone: +49 228 2016020 • Fax: +49 228 2016029 info@biobserve.com

North America: 2125 Center Ave. • Suite 500 • Fort Lee, NJ 07024 Phone: 201-302-6083 • Fax: 201-302-6062 info@biobserve.com