Behavioral Neuroscience, Jamming Avoidance Response
USD Department of Biology
Behavioral Neuroscience
Electric Fish and JAR Behavior
Afferent Path of Electroreception
Control of Electric Organ Discharge
Efferent Output producing EOD
Jamming Avoidance Response
Electric field Glutamate
Electric Fish Figures
Electric Fish Circuitry
Acronyms/Abbreviations    end
Jamming Avoidance Response
1) Electric Field

2) Directional Changing of EOD

3) Interference and Reinforcement

The jamming avoidance response. a | Diagram of the electric field of a wave-type electric fish (shown in outline). Current vectors (blue arrows) and isopotential lines in 1-mV contours (green, red) are for the head-negative phase of the electric organ discharge (EOD). Reproduced, with permission, from REF. 58 © (1999) Company of Biologists. b | Representation of jamming avoidance responses (JARs) of two wave-type fish (Eigenmannia). The EODs of these fish are normally emitted at a highly regular frequency (250 Hz for one fish, 254 Hz for the other) and generate a quasi-sinusoidal signal. These two signals summate to produce the ‘beating’ waveforms (centre), wherein the peak-to-trough amplitude fluctuates over time at a rate equal to the frequency difference of the EODs of the two fish (4 Hz in this example). During the JAR, fish change their EOD frequency so as to increase the frequency difference; the higher frequency fish raises its EOD frequency and the lower frequency fish decelerates its signal. c | Sinusoidal representations of the EODs of two fish, and the signal that results from the addition of these signals (S1 + S2). The signal of the neighbour (S2) is smaller and of a higher frequency than that of the focal fish. The amplitude and phase of the combined signal fluctuates over time as the two signals slowly and regularly move in and out of phase. The amplitude peak of the combined signal corresponds to the point in time when S1 and S2 are in phase (reinforcement); at the beat minimum, the two signals are in antiphase (interference). The timing of zero-crossings of the combined signal, relative to those of S1, are delayed as the amplitude rises, and advanced as the amplitude falls; this relation between amplitude and phase modulations is reversed when the frequency of S2 is lower than that of S1 (phase advance accompanies increases in amplitude).

References on the WWW:

Electric Organ Discharge:


Electric fish:
Research of Dr. Harold Zakon @
Electric Rays:

Family of the elecrtric rays:

Marbled Electric Ray:

Torpedo californica:

Torpedo electric organ

Rays - what's that?

Fish Species database:
Jamming Avoidance Response: