Outline of a Cue Editor - Brain Theory from a Circuits and Systems Perspective - page 89

Fig. 5.6 Pulse counter using toggle elements

The ModCues signal is reapplied after each failure to find a match, that is, for each
NoHit signal. ModCues(i) is assumed to lower the frequency of multivibration very
slightly each time it . Consequently, as successive

modifications occur there will be an ever-decreasing number of cues, and an ever-
increasing chance of a match in long-term memory.

is applied i ¼ 1, 2, 3,

...

Pseudorandom Cue Selection

The section mentions an entirely different approach based on a pseudorandom
number generator. Recursive neurons that toggle are available and may constitute
various registers and counters, in analogy to classical digital design. It is helpful to
have an overview of these in order to understand pseudorandom number generation
using toggles.

Pulse Burst Counter

Figure 5.6 sketches a plan for a pulse burst counter.
Synapse S1 serves to convert a first pulse burst into a single pulse that is used to
toggle Tog1 from 0 to 1. This produces the least significant bit of a binary count Q 0 .
The next pulse to Tog1 returns Q 0 back to 0; before this occurs, U1 enables a pulse
to Tog2 moving Q 1 from 0 to 1. The result for two stages is a binary count Q 1 ,
Q 0 ¼ 0, 0; 0, 1; 1, 0; 1, 1. A two-bit counter element is defined in the figure. These

counter elements may be cascaded to produce a count of any number of bits.