Further analysis of sensory coding in electroreceptors of electric fish.

Abstract

Sternopygus displays nonsynchronous, tonic "position" and phasic "movement" units and units which are synchronous (with electric organ discharge) and tonic in response to objects near the fish. Some of the latter code by systematically shifting spike phase (latency) relative to the electric organ; this may be a new form of nerve impulse code. Some code by shifting the probability of firing but, strangely, without any phase shift. Patterns of runs and misses in the last group show a strong negative serial correlation for 2 or more intervals. Non-synchronous units are not only uninfluenced by electric organ frequency but still respond to objects after electric organ silence. The remarkable variety of types of electroreceptors bespeaks differentiation of functions.