Described here is a compact and battery-operated unit that produces a short audible signal at uniform intervals, variable from 2 sec to 2 min.
A shock scrambler using photoelectric conductors which operate relays is described. The scrambler has advantages of low cost and reliable operation.
Three primary methods of recall (free association, free recall, stimulated recall) and two modifications of them (modified free association, modified stimulated recall) were defined by use of three variables: (a) presence or absence of prior laboratory training, (b) presence or absence of E controlled test stimulation, and (c) test instructions to free associate or to recall Data ...
An electric retraction mechanism, which is adaptable to a wide range of operant manipulanda, was developed. Miniaturized, inexpensive toy railroad equipment was used to simplify construction. The mechanism, utilized as a retractable rat lever, has operated reliably and uniformly over a range of independent retraction and extension times.