Some Electronic Control Units for Operant Behavior Studies: I. A Response and Reinforcement Contingency Translator1

We have developed in our laboratory a versatile translator for response events and reinforcement contingencies.We have used it extensively, and it has reached a stage of de- velopment in which its functioning is of high reliability.The unit is a central one around which various types of auxiliary apparatus may b'e employed to produce a wide variety of experimental conditions.In subsequent apparatus notes, we will describe several of the supplementary systems we are using in the study of temporal schedules of reinforcement.Among the functions of the translator the following may be noted: (a) it accepts re- sponse data electronically (in the form of pulses); (b) it passes these data to recording devices; (c) on external signal, it provides a timed reinforcement for the next response or for any number of subsequent responses; (d) on another external signal, it removes rein- forcement availability; (e) on an external panel, it permits manual testing of each of its functions.The control unit has a number of advantages for behavior researches, including the ability to handle very high rates of responding (surpassing the response rate of any known organ- ism, and approaching, if not surpassing, the limit of any currently available recording or print-out device).It can be driven by any experimental programing system at virtually un- limited speed (up to 100 kilocycles).It is compact, and provides long trouble-free operation.The circuit diagrams of the apparatus are given in Figs. 1 and2, each accompanied by an index of components.The operation of both circuits may be traced as follows:(1) The response pulse is generated by closure of the pigeon key (K), or, if switch SI is thrown, key pecks may be manually simulated by push button BI on the control panel.K, of couse, may be any manipulandum operating as a switch.(2) Each closure of K operates relay RYI, feeding a response pulse into the one-shot (El), which in turn puts out a square wave of consistent amplitude and duration.The latter operates the Sodeco response counter through the circuit involving half of tube T1 and relay RY3.The occurrence of a response is also indicated on the panel face by a flash of neon light N3.The duration of the standard pulse from El is controlled by the magnitude of capacitor C2, for which a value must be chosen that provides an output pulse of sufficient duration for the operation of the particular recording mechanism being used.(We have found 0.05 microfarad a satisfactory value of C2 for both Sodeco counters and Gerbrands cumulative recorders.)Most recording devices have a sizable refractory period which must be taken into account in the setting of C2.Response events within the refractory period of the recorder can be reinforced by the present system, if so desired.Mechanical counters do not have the resolving power for responses which this electronic system provides, but elec- tronic counters of very short refractory period are available with counting resolution which can be made equal to the resolution of the present reinforcement system, if necessary.