See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/6972916 Behavior simultaneously maintained by both presentation and termination of noxious stimuli Article in Journal of the Experimental Analysis of Behavior · June 1978 DOI: 10.1901/jeab.1978.29-375 · Source: PubMed CITATIONS READS 20 46 2 authors , including: James E Barrett Drexel University College of Medicine 238 PUBLICATIONS 4,915 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Pain research and drug discovery View project Neuroactive Steroids View project All content following this page was uploaded by James E Barrett on 04 June 2014. The user has requested enhancement of the downloaded file.
1978, 29, 375-383 NUMBER 3 (MAY) JOURNAL OF THE EXPERIMENTAL ANALYSIS OF BEHAVIOR BEHA VIOR SIMULTANEOUSLY MAINTAINED BY BOTH PRESENTATION AND TERMINATION OF NOXIOUS STIMULI' JAMES E. BARRETT AND ROGER D. SPEALMAN UNIVERSITY OF MARYLAND AND HARVARD MEDICAL SCHOOL AND NEW ENGLAND REGIONAL PRIMATE RESEARCH CENTER Lever pressing by two squirrel monkeys was maintained under a 3-minute variable- interval schedule of response-produced electric-shock presentation. At the same time, re- sponding on a second lever was maintained under a 3-minute fixed-interval schedule of termination of the shock-presentation schedule and shock-correlated stimuli. Under the termination schedule, the first response after a 3-minute period produced a 1-minute timeout, during which no events occurred and responding had no scheduled consequence. Relatively high and constant rates of responding were maintained on the lever where responding produced shock. Lower rates and positively accelerated patterns of responding occurred on the lever where responding terminated the shock schedule. Thus, responding was simultaneously maintained by presentation of an event and by termination of a stimulus associated with that event. Rates and patterns of responding on each lever were reversed when the schedules arranged on each lever were reversed on two occasions. When shock intensity was increased from 0 to 10 mA, responding maintained both by presenta- tion of shock and by termination of the shock schedule increased, but responding main- tained by shock presentation increased to a greater extent. Positive and negative rein- forcement, usually regarded as separate behavioral processes involving different events, can coexist when behavior is controlled by different contingencies involving the same event. Key words: response-produced shock, stimulus-shock termination, positive reinforcement, negative reinforcement, variable-interval schedules, fixed-interval concurrent schedules, schedules, electric shock, squirrel monkeys Under many circumstances, organisms ment. Whereas the process of negative rein- ter- minate noxious environmental events and stim- forcement refers to increases in responding uli associated with them (e.g., Azrin, Holz, and that result from the termination of an event Hake, 1962; Dinsmoor, 1962; Dinsmoor and and stimuli associated with it, positive rein- Winograd, 1958; Kaplan, 1956; Keller, 1941; forcement refers to increases in responding Morse and Kelleher, 1966). Behavior main- that result from the presentation of an event. tained in this manner has often been classified Sometimes, it also is assumed that events that function as either positive or negative rein- as escape behavior and the process termed neg- forcers exclusive ative reinforcement (Fantino, 1973; Reynolds, belong to mutually cate- 1975; Skinner, 1953). A distinction is usually gories and that the behavioral effects of those made between negative and positive reinforce- events depend entirely on their intrinsic physi- cal properties. Several experiments (e.g., Byrd, 1969; Kelle- 'Supported by grants AA-02104, DA-01839, and MH- her and Morse, 1968; McKearney, 1968),. how- 14275 from the Public Health Service and by contract ever, have cast doubt on these two assumptions DAMD 17-77-C-7001 from the U. S. Army Medical Research and Development Command. We thank J. L. and have demonstrated convincingly that the Katz, R. T. Kelleher, J. W. McKearney, and W. H. behavioral effects of an environmental event Morse for their helpful comments, and Joanne Delaney, are not an immutable property of that event. Nancy Gehman, Jennifer Stanley, and Beth Weinberg In these studies, characteristic schedule-con- for secretarial and technical assistance. Reprints may trolled rates and temporal patterns of respond- be obtained from J. E. Barrett, Department of Psy- chology, University of Maryland, College Park, Mary- ing were maintained when the sole conse- 20742 Spealman, Medical land or R. D. Harvard of responding was quence the delivery of School, New England Regional Primate Research Cen- electric shock-an event often believed to main- ter, One Pine Hill Drive, Southborough, Massachusetts tain responding by its removal, rather than 01772. 375
JAMES E. BARRETT and ROGER D. SPEALMAN 376 uli. Only the white lamps were used in the by its presentation. Other experiments (e.g., Barrett and Glowa, 1977; Kelleher and Morse, present study. The monkey's tail was held 1968; McKearney, 1972) have shown that under motionless by a small stock located below the waist lock and fitted with brass electrodes that suitable conditions shock can both maintain rested on a shaved portion of the tail. Elec- and suppress responding in the same organism trode paste (EKG sol) ensured a low-resistance at about the same time. In these studies, shock maintained charac- contact between the electrodes and the tail. response-produced Electric shock could be delivered to the tail teristic schedule-controlled performances in from a 650-V ac, 60-Hz transformer. The dura- one component of a multiple schedule, but tion of shock was held constant at 200 msec. suppressed responding in another component. Shock intensity was determined by a variable Such findings illustrate that factors other than the physical properties of an environmen- resistor in series with the monkey's tail and was monitored continuously by an alternating tal event can be important determinants of the way that event controls behavior (see re- current meter (Simpson #1257). The chair was views by Morse and Kelleher, 1970, 1977). placed inside a sound-attenuating enclosure furnished with a ventilation fan and white In the present experiment, separate re- masking noise. Scheduling and recording equip- sponses of individual squirrel monkeys were developed and then maintained simultaneously ment was located in a separate room. both by shock presentation and by termination of the shock schedule and visual stimuli as- Procedure sociated with shock. Positive and negative re- Previously, each monkey had been trained inforcement, usually considered to be separate to respond under variable-interval and fixed- and independent processes involving different interval schedules of response-produced elec- events, were obtained simultaneously when tric shock according to the general method behavior was controlled by different contin- described by McKearney (1968). Briefly, this gencies involving the same environmental consisted of initial training under a shock- event. postponement (avoidance) schedule (Sidman, 1953) for about two weeks. During this time, METHOD each response postponed electric shocks for 25 Subjects sec (response-shock interval = 25 sec). In the Two mature male squirrel monkeys (Saimiri absence of responding, shocks occurred every 5 sciureus), with experience under various food- sec (shock-shock interval = 5 sec). Next, a variable-interval schedule of response-produced and shock-presentation schedules, were used. electric shock was arranged concurrently with Both monkeys weighed approximately 750 g. Each was housed individually and had un- the shock-postponement schedule. After about restricted access to food and water except dur- two weeks, the shock-postponement schedule ing experimental sessions. was discontinued and responding was main- tained solely under the variable-interval sched- Apparatus ule of electric-shock presentation. Each mon- During experimental sessions, each monkey key was later studied under a fixed-interval sat in a Plexiglas chair and was restrained in schedule of shock presentation. Without further preliminary training, the the seated position by a waist lock (cf. Hake and Azrin, 1963). Two response levers (BRS/ monkeys were exposed to a variable-interval LVE #121-05) were mounted on a transparent schedule, under which responding on the wall in front of the monkey, 8 cm above the right lever (initially, the only lever present) 13 cm apart. Operation of produced a 7-mA electric shock on the aver- waist lock and either lever by a minimal downward force of age of once every 3 min. The variable-interval 0.20 N produced an audible click of a relay schedule was made up of 15 different time mounted behind the front wall and was re- intervals derived from a constant-probability corded as a response. Pairs of red, green, and distribution (Catania and Reynolds, 1968) and white lamps (7.5 W, 115 V ac), mounted at arranged in an irregular order. Sessions lasted eye level behind the transparent front wall, 60 min, during which the white stimulus lamps could be illuminated and used as visual stim- illuminated the chamber.
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