Continuous reinforcement schedule

Experiments are conducted in commercially available operant chambers (Coulboum Instruments, Allentown, PA 18106, USA), equipped with two response levers, a food hopper and receptacle, stimulus lights and an exhaust fan. Male rats (225-250 g) are housed individually and maintained under a non-inverted 12/12 hr light/dark cycle with restricted access to food (15 g per day). Lever training begins under a continuous reinforcement schedule of food presentation. Daily sessions are terminated after 1 hour or 50 food presentations, whichever occurs first. Subsequently, the response requirement is increased by one response per daily session up to FR5. Once rats receive 50 food pellets in a single session under the FR5 schedule (typically within 5 days), food training is suspended and... 

McCullough LD, Cousins MS, Salamone JD (1993a) The role of nucleus accumbens dopamine in responding on a continuous reinforcement operant schedule a neurochemical and behavioral study. Pharmacol Biochem Behav 6(3) 581-586. 

In the real world, consequence stimuli do not necessarily follow every occurrence of the response. In fact, typically, consequences follow the response on an intermittent basis. Paychecks, for example, are typically distributed on a weekly, biweekly, or even monthly basis, not after each instance of work-related activity that occurs. The pianist plays the entire piece of music before the audience applauds. This strategy of intermittent reinforcement of responding actually provides greater behavioral efficiency and economy as well as greater response strength and persistence than does continuous reinforcement. A response that has been reinforced after every occurrence declines much more rapidly when reinforcement is withheld (extinction) than does one that has been reinforced on an intermittent schedule. 

Solinas M, Panlilio LV, Antoniou K, Pappas LA, Goldberg SR. The cannabinoid CB 1 antagonist N-piperidinyl-5-(4-chlorophenyl)-l-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide (SR-141716A) differentially alters the reinforcing effects of heroin under continuous reinforcement, fixed ratio, and progressive ratio schedules of drug self-administration in rats. J. Pharmacol. Exp. Ther. 306, 93-102 (2003). 

Consider some applications of these reinforcement schedules in the study of foods. A particularly useful feature of the Interval schedules is that they allow the investigator to space periods of food ingestion throughout a lengthy test session without sacrificing a continuous record of the indicator response. 

AntheneUi RM, Despres IP (2004) Effects of Rimonabant in the reduction of major cardiovascular risk factors. Results from the STRATUS-US trial (smoking cessation in smokers motivated to quit), American College of Cardiology 53rd Annual Scientific Session, New Orleans, LA Arroyo M, Markou A, Robbins TW, Everitt B1 (1999) Acquisition, maintenance and reinstatement of intravenous cocaine self-administration under a second-order schedule of reinforcement in rats effects of conditioned cues and continuous acces to cocaine. Psychopharmacology 140 331-344... 

Only a few behavioral studies have so far been reported with these modulated RF fields. Chicks exposed to 450 MHz, 1 or 5 mW/cm2 fields sinusoidally modulated at 3 or 16 Hz during performance of a fixed-time 30 sec schedule of water reinforcement showed trends towards longer latency of response (44). In Soviet studies, rabbits and rats chronically exposed for 120 days to extremely low levels of 50 or 2500 MHz continuous fields or 10 GHz fields pulsed at 1000 or 20 Hz showed statistically significant alterations in conditioned reflexes with field intensities between 1.9 and 2.0 yW/cm2. A 2450 MHz, 1 mW/cm2 microwave field pulsed at 1000/sec had a synergic effect on the action of Valium (chlordiazepoxide) on fixed-interval behavior in rats (46). 

Intermittent schedules may also be maintained by negative reinforcement, usually by a brief mild electric shock. The most popular of these is continuous or Sidman avoidance in which each response postpones a shock by a fixed amount of time. By spacing its successive responses within this time interval, the animal may postpone shock indefinitely. This schedule is particularly useful as a comparison to behavior generated by positive reinforcement if a toxicant is suspected of producing anorexia. Simple intermittent schedules such as these have been used fairly widely in behavioral toxicology and have proved to be sensitive to the effects of a number of industrial and environmental toxicants. 

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