ABSTRACT
Figure 1: RAW EXPERIMENTAL DATA. SENSORY TRANSDUCTION. SPIKE TRAINS IN FIRST-ORDER AFFERENTS. I. LENGTH MODULATION AT DIFFERENT FREQUENCIES. NOISE WITH DIFFERENT AMPLITUDES. INDIVIDUAL CYCLES. (Crayfish fast adapting stretch receptor organ FA 0). As compared with the clean case (A), discharges with noise become less regular, occupy a larger portion of the cycle and show more spikes per cycle. This increases from weaker (B) to stronger (C) noise. Upper record from first order afferent. Lower record length: modulation depth 0.180mm (receptor length 6.0mm), frequency O.2Hz and 1.0Hz (time calibrations 0.505s, 0.100s). [16] II. SPATIAL ORIENTATION MAINTAINED AND TRANSITIONS. NOISE. CHANGE IN RATES, IN VARIABILITIES, AND IN CHARACTER FROM PHASIC TO TONIC AFFERENT. (isolated guitar-fish utricle) Upper record, electrical activity from a single twig with action potentials from two cells. Lower record, orientations A and B; the representations of the transitions and of the noise or jitter .J are only approximate. The small spike without jitter slows on passing from A to B, and its fully-adapted rate at B is lower than at A; with jitter (+J) it irregularized, accelerated on passing back from B to A and its fully-adapted rate is higher than at B. The large spike without jitter (upper part) is active only during the transition, and not otherwise. With jitter {+J} it fires during transitions; furthermore, shows a fully adapted discharge at both orientations, firing faster at A, than at B {where firing was very slow, and no spike appears in the figure}, thus shifting its character from a phasic to a tonic.
