Behavioral momentum and the partial reinforcement effect.

Free-operant behavior is more resistant to change when the rate of reinforcement is high than when it is low. The usual partial reinforcement extinction effect, demonstrating greater resistance to extinction after intermittent than after continuous reinforcement, seems to contradict this generalization. However, most free operant extinction data are reported as response totals, which confound the initial levels of responding and the rate at which responding decreases over the course of extinction. A reanalysis showed that after extended training, the slope of the extinction curve is shallower after continuous reinforcement than after intermittent reinforcement, suggesting greater rather than less resistance to change. The results, which hold for both independent-groups and within-subject comparisons, support the general finding that resistance to change of free-operant behavior is a positive function of the rate of reinforcement. This generalization does not, however, hold for discrete-trial performance. I discuss some consequences of these analyses for applications of behavioral research results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of intermittent and constant punishment on resistance to punishment in a free operant situation for the albino rat.

Trained male Wistar albino rats (10 experimental and 9 control Ss) to barpress for food reinforcement in a 2-bar cyclic response chain situation. Responding on 1 bar led also to a punishment (footshock) on either an intermittent or constant schedule. Both punishment schedules led to increased responding on the nonpunished bar and to initial response suppression followed by recovery on the punished bar. For Ss on the intermittent schedule, the response increase on the nonpunished bar was seen only after a punishment on the other bar. Similar effects were found for transfer time between the 2 bars. The effects of punishment on response to both bars were more pronounced for the intermittent punishment groups. Results are discussed in terms of the motivational constructs of A. Amsel and of R. K. Banks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Punishment of consummatory and instrumental behavior: Effects on licking and bar pressing in rats.

Maintained licking and bar pressing in 48 male hooded rats by intermittent water reinforcement. Shock punishment was delivered for either a reinforced or nonreinforced lick or bar-press response. Punishment suppressed licking more than bar pressing. Pairing punishment with reinforcement had little effect on overall response suppression. In Exp. II with 18 Ss, Ss punished for the 1st lick after a reinforced bar press showed more response suppression than Ss punished for the reinforced bar press. Results support R. Solomon's (see record 1965-00694-001) hypothesis than consummatory behavior is more sensitive to punishment than instrumental behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Punishment contingencies for the reduction of incorrect responses during articulation instruction

A comparison was made between the effects of punishment combined with positive reinforcement and reinforcement alone for the reduction of incorrect articulation responses. Three different punishers (a buzzer, response cost, and "No!") were studied for six young children while they were receiving programmed articulation instruction. The results indicated (1) that punishment in combination with positive reinforcement was generally more effective than positive reinforcement alone; (2) that whether or not a particular stimulus acted as a punisher could be determined only be empirical demonstration; and (3) that the introduction of punishment contingencies did not produce increased rates of disruptive, off-task behaviors. Conversely, off-task behaviors tended to increase in rate when punishement contingencies for articulation responses were removed.     

The effects of diagnostic category and reinforcer on learning without awareness.

Learning without awareness was tested by asking Ss to construct sentences using pronouns (I, we, he, they) and verbs presented to them. 3 groups were employed—normals, neurotics, and schizophrenics, under 4 experimental conditions: (a) E "rewarded" (said "good" to) 2 of the pronouns (I, we); (b) the use of he or they was "punished" ("not so good"); (c) differential reinforcement as was appropriate re: "punishment" and "reward" when employing the pronouns; (d) control. Results: normals profited well from all conditions of reinforcement; neurotics, only from reward or reward and punishment; schizophrenics, from punishment alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Persistence of runway performance after septal lesions in rats.

Assigned 32 male Wistar albino rats to groups receiving bilateral septal lesions or control operations. Septal lesions prevented the partial reinforcement extinction effect after 48 acquisition trials. Septal Ss showed increased resistance to extinction following continuous reinforcement but decreased resistance to extinction following partial reinforcement. Analysis of the acquisition data indicated that the lesions retarded the development of approach-avoidance conflicts associated with reward and nonreward. In a 2nd study, 16 septal and 16 control Ss received 96 acquisition trials. Extended training allowed the development of conflict responses under partial reinforcement, and the Ss with lesions were indistinguishable from controls during extinction. Following continuous reinforcement, septal lesions produced slower extinction of response. It is concluded that the lesions interfered with the development of feedback from frustration, approach-avoidance conflicts, and frustration tolerance. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extinction of persistence in a within-subject partial reinforcement experiment.

Male albino Wistar rats (N = 96) served as Ss in 2 within-S partial reinforcement experiments, designed to lessen generalization in acquisition as a means of eliminating the generalized partial reinforcement effect in extinction. When the use of a separate-phase mode of training alone proved to be unsuccessful for this purpose, a phase of extinction was interpolated between the continuously and partially reinforced acquisition phases. This manipulation was successful and Ss receiving the training sequence of partial reinforcement-extinction followed by continuous reinforcement-extinction did not show the generalized partial reinforcement effect in the final extinction phase. It is suggested that during the phase of interpolated extinction avoidance responses were counterconditioned to the stimulus complex which included nonreward. (French summary) (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of intermittent and continuous token reinforcement on bus ridership.

The following conditions were successively instituted on an experimental bus (the 11:00 AM–2:00 PM daily operation of a campus bus): baseline, VR-3 token reinforcement (every 3rd passenger, on the average, received a token worth about 10 cents for boarding the bus), continuous token reinforcement (every passenger received a token), VR-3 token reinforcement, and baseline. Compared to the experimental controls, experimental bus ridership increased significantly during token reinforcement manipulations. There was no difference in the effects of VR-3 and continuous token reinforcement. Results suggest that compared to continuous token reinforcement, intermittent token reinforcement may provide a viable and economical appproach to increasing bus ridership. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of partial reinforcement on tolerance to morphine-induced analgesia and weight loss in the rat.

Groups of 60 male Sprague-Dawley rats were presented a distinctive set of environmental cues on several occasions. For 1 group, morphine (40 mg/kg) was injected each time the cues were presented (morphine/continuous reinforcement). For a 2nd group, morphine was injected only following 1 of 4 cue presentations (morphine/partial reinforcement). Two additional groups were injected with only saline, one on the continuous reinforcement schedule and the other on the partial reinforcement schedule. Results demonstrate less tolerance to morphine in the partially reinforced morphine-injected Ss than in continuously reinforced morphine-injected Ss. Unlike other demonstrations of a tolerance-retarding effect of partial reinforcement, findings did not result from nonassociative factors related to differential novelty, stress, or practice. Clinical implications for the tolerance-retarding effect of partial reinforcement are discussed. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for a transitional period for development of persistence in infant rats.

Conducted 4 experiments with a total of 188 rat pups to test the hypothesis that rat pups can learn persistence at age 11 days but cannot express this learning in their behavior until they are a few days older. Exp I used a space-trial procedure to investigate the relative reinforcing effects of milk suckling, dry suckling, and contact without suckling at ages 11 and 14 days. Exp II used the Exp I procedure, manipulating schedule of reward at 2 ages and under 2 of the reward conditions. Exp III manipulated the dry suckling reward schedule in 11- and 14-day-old pups. Exp IV manipulated partial and continuous reinforcement on Day 11 but tested for persistence on Day 14. Results suggest the existence of a traditional period in neonatal rats for the learning of persistence. Partial reinforcement training with suckling on an anesthetized dam as reward induced greater persistence in extinction of the approach response than did continuous reinforcement in rat pups 14 days old but not in 11-day-old pups. Other aspects of this period of development are discussed. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of continuous and partial reinforcement and methylphenidate on learning in children with attention deficit disorder.

Measured the performance of 30 children (aged 5 yrs 11 mo to 11 yrs) with attention deficit disorder (ADD) on a nonsense-word spelling task. The effects of 2 reinforcement schedules, partial and continuous, and methylphenidate (MPHN [0.3 mg/kg]) were assessed. Ss were assigned to 1 of 3 groups—no reinforcement, continuous reinforcement, and partial reinforcement. They performed the spelling task twice, once after ingesting MPHN and once following placebo ingestion. Results indicate that both reward conditions had large and equivalent beneficial effects on learning, as did MPHN. When reinforcement was combined with MPHN, performance was maximized. The results fail to support V. I. Douglas's (1983, 1985) hypothesis that partial reinforcement schedules have adverse effects on hyperactive children. The results also demonstrate the incremental value of the combination of MPHN and reinforcement in treatment of ADD. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response suppression in humans as a function of contingent and non-contingent punishment: Signal properties of stimuli.

Trained an instrumental goal (G) response in 40 undergraduates in 4 groups under intermittent reward (money). When the acquisition criterion was met, reward was withdrawn and different punishment treatments administered. Group C received contingent punishment (electric shock) of the G response whenever it was omitted. Shock occurring on a variable interval schedule provided noncontingent punishment to another group (NC). Contingent and noncontingent punishments were combined and administered to Group C and NC. The 4th group (E) served as a control and received no punishment. This entire study was repeated, and both experiments indicate that the C treatment yielded most suppression, even exceeding that obtained under the C and NC procedure which administered more punishments. Results favor the notion that punishment acts in an analogous, but opposite direction to reward, and that its consequences may be predicted on the basis of the consistency of the information conveyed by a punisher. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fixed-ratio schedules increase generalized self-control: Preference for large rewards despite high effort or punishment.

Three experiments investigated the effects of FR reinforcement on generalized self-control involving high effort and punishment. In Experiment 1, rats received food in a runway for the completion of each round trip (continuous-reinforcement group) or every fifth round trip (FR group). Control rats received food at the same temporal intervals as these groups but without any instrumental requirement. When all rats were next given a series of choices between a large food reward requiring high lever force versus a small reward requiring low lever force, the FR rats showed the greatest self-control. In Experiments 2 and 3, rats were rewarded on a continuous or FR schedule followed by choice between a large food reward accompanied by intermittent shock vs a small or absent food reward without shock. The FR rats again showed the greatest self-control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Within subjects partial reinforcement extinction effects for a bar pressing task.

Trained 24 male albino Sprague-Dawley rats to barpress for water during both continuous and partial reinforcement of their responses. In extinction, Ss trained to press 1 bar during continuous reinforcement and a 2nd bar during partial reinforcement made more correct responses in the partial than in the continuous reinforcement condition. No difference in response rates was observed for Ss who learned the same response during both reinforcement schedules. Pairing different lighting conditions with the different schedules of reinforcement had no effect on these results, but did affect other response measures. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Durability and generalizability of persistence training.

40 male and 40 female college students experienced either partial reinforcement (persistence training) or continuous reinforcement on either of 2 instrumental tasks (finger shuttle or button press) as therapy for failure-induced depression and subsequently were exposed to protracted failure (extinction). Following this initial extinction phase all Ss received continuous reinforcement on a common instrumental task (button press) as therapy and then encountered extinction (consecutive failure trials) for a 2nd time. Results show that increased persistence occasioned by partial-reinforcement therapy was able to survive interpolated periods of extinction and continuous reinforcement; that is, durable persistence training effects were shown. Furthermore, persistence training effects were shown to be generalizable (the persistence advantage associated with partial-reinforcement therapy transferred across topographically different responses), but the generalization process was not a complete one. The results are discussed within the frameworks of frustration theory and alternative cognitive theories. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acquisition With Partial and Continuous Reinforcement in Rat Magazine Approach.

Partial reinforcement, compared with continuous reinforcement, is widely considered detrimental to Pavlovian conditioned responding. However, time-accumulation models predict an invariance in acquisition when learning is assessed as a function of number of reinforcements, not trials, and intertrial interval is held constant. Three experiments examined this prediction in a rat magazine-approach procedure. All experiments showed superior responding with continuous reinforcement. Experiments 1 and 3 used common tests in between- and within-subject designs, respectively. Experiment 2 showed the same pattern in a discrimination. Earlier results are reanalyzed informally and in a meta-analysis. Contrary to previous summaries of the literature, evidence points to superior conditioned responding with continuous reinforcement in a number of procedures. Results are generally consistent with traditional associative models of learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning theory approach to the deterrence of criminal recidivism.

Data on punishment and criminal arrests in a total birth cohort of men in Denmark (N?=?28,879) were used to test the following hypotheses derived from learning theory: (a) the imposition of sanctions reduces rates of subsequent criminal arrest; (b) the more severe the sanction received for an arrest, the lower the rate of recidivism; (c) different types of sanctions have similar effects on recidivism; (d) the higher the proportion of sanctions received for past arrests, the lower the rates of future arrest; (e) continuous sanctions reduce arrest rates more than intermittent sanctions; and (f) discontinuation of punishment results in recovery of criminal arrests. Results support the above hypotheses, except Hypothesis b; our results suggest that sanctions have similar effects on recidivism regardless of their severity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Importance of trials versus accumulating time across trials in partially reinforced appetitive conditioning.

Four experiments with rats examined partial reinforcement in appetitive conditioning. In Experiment 1, adding nonreinforced trials to a continuous reinforcement schedule slowed acquisition, whereas deleting reinforcers did not. Trial massing suppressed performance and learning. In Experiment 2, conditioning with a short conditioned stimulus (CS) was rapid, and partial reinforcement with a short CS was as effective as continuous reinforcement with equal accumulated time in the CS. In Experiment 3, conditioning was nevertheless influenced by the probability of reinforcement. In Experiments 3 and 4, conditioning was especially disrupted when nonreinforced trials preceded reinforced trials closely in time. The results underscore the importance of temporal variables in conditioning but are more consistent with trial-based accounts than time-accumulation accounts of conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of acquisition training schedule on extinction and reinstatement of cocaine self-administration in male rats.

Partial reinforcement is known to increase resistance to extinction (Rn) relative to training with continuous reinforcement. This phenomenon, referred to as the partial reinforcement extinction effect, is one of the most robust in learning and conditioning studies. Experiment 1 investigated manipulations known to affect the partial reinforcement extinction effect and determined their possible relevance for drug use patterns. Male rats received intravenous cocaine self-administration training under partial reinforcement (FR-10) training or continuous reinforcement (FR-1) conditions with either a low (0.25 mg/kg infusion) or a high cocaine dose (1.00 mg/kg infusion). Animals were placed on an extinction (recurrent nonreward) schedule for 10 days (1-hr sessions) prior to being tested for cue-induced reinstatement (single 2-hr session). Experiment 2 involved acquisition of cocaine self-administration under FR-1 conditions of short training (15 days) or extended training (30 days) with a low dose (0.25 mg/kg infusion) or a medium dose (0.50 mg/kg infusion) of cocaine reward prior to extinction or reinstatement. Experiment 1 showed that rats trained with FR-10-high dose outcomes exhibited greater Rn than the remaining groups. Additionally, FR-10-high dose and FR-10-low dose rats were more likely to return to active drug seeking during the reinstatement test. In Experiment 2, rats trained under FR-1-medium dose conditions were more persistent during extinction following short acquisition training than comparable rats experiencing extended acquisition training. The reinstatement test was conducted following extinction, in which it was observed that overtraining under FR-1-medium dose reward schedules resulted in a decrease in the tendency to return to active drug seeking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The strength of the orienting response during Pavlovian conditioning.

Exp I, with 8 male hooded-Lister rats, demonstrated that the orienting response toward a light that signaled food declined in strength during conditioning but was temporarily restored during extinction. In Exp II, using 24 male Sprague-Dawley rats, the light was paired immediately with the UCS; but in Exps III and IV (40 male Sprague-Dawley rats), it signaled a tone that in turn signaled the UCS. Exps II–IV showed that continuous reinforcement resulted in a decline in the strength of light orientation. Under conditions of partial reinforcement, orientation to the light was sustained. Exp V, with 32 male Sprague-Dawley rats, demonstrated that the decline in light orientation with a continuous reinforcement procedure was retarded either by preexposing the light for a number of trials prior to conditioning or by intermixing reinforced light trials with nonreinforced presentations of a tone. Reversing the reinforcement contingency associated with the tone restored orientation to the light. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)