Variability of response location for pigeons responding under continuous reinforcement, intermittent reinforcement, and extinction

The effect of several reinforcement schedules on the variability in topography of a pigeon's key-peck response was determined. The measure of topography was the location of a key peck within a 10-in. wide by 0.75-in. high response key. Food reinforcement was presented from a magazine located below the center of the response key. Variability in response locus decreased to a low value during training in which each response produced reinforcement. Variability increased when fixed intervals, variable intervals, random intervals, or extinction were scheduled.     

Perseveration of the partial reinforcement effect in extinction with rats over two phases of extinction and two stages of continuous reinforcement

One group of 10 male albino rats was given partial reinforcement while the other 10 rats received continuous reinforcement in a straight alley. Subjects then experienced five consecutive stages of Extinction 1, Continuous Reinforcement 1, Extinction 2, Continuous Reinforcement 2, and finally, Extinction 3. Analysis showed the partial reinforcement effect in extinction was sustained over two stages of extinction and two stages of continuous reinforcement, since subjects receiving partial reinforcement ran faster than rats given continuous reinforcement throughout all three of the extinction periods. The results seem to support those of Amsel's (1967) and Cabpaldi's (1967) theoretical formulations of the partial reinforcement effect in extinction.     

Resistance to continuous delay of reinforcement or extinction following partial delay or partial reinforcement in acquisition: A direct comparison

Rats received either partial reward (PR) or partial delay (PD) in acquisition with one, two, or three delay or nonreward trials followed by an immediately rewarded trial or one delay or nonreward trial followed by an immediately rewarded trial. These four groups were then split in half and given either continuous delay or continuous nonreward (extinction) in a “response persistence” phase. In addition, two continuously reinforced groups, one experiencing continuous delay, and the other experiencing extinction were included. The results showed that response persistence was greater when PD groups were given continuous delay rather than extinction, but the opposite was true for PR groups. The “length” (1, 2, or 3 versus 1 nonreward or delay trial) also transferred to the response persistence phase with the length 1, 2, and 3 conditions being more persistent than the 1 length conditions. The results were discussed with respect to theoretical notions of response persistence.     

Transfer of approach responding between punishment and frustrative nonreward sustained through continuous reinforcement

A block of continuously reinforced nonpunished trials was interpolated between acquisition of a runway response with either partial reinforcement or intermittent punishment and subsequent tests for resistance of that response to the suppressive effects of either extinction or continuous punishment. As previous investigations have shown, both the partial reinforcement effect (PRE) and the intermittent punishment effect (IPE) were sustained through the block of continuously reinforced nonpunished trials. Furthermore, the increased resistance to extinction following intermittent punishment and the increased resistance to punishment following partial reinforcement were also sustained through the interpolated continuous reinforcement. These results support a hypothesized similarity of punishment and frustrative nonreward and were interpreted in an extension of Amsel's conditioning model theory of the role of nonreinforcement in the PRE.     

Survival of the partial reinforcement extinction effect after contextual shifts

The effects of contextual shifts on the partial reinforcement extinction effect (PREE) were studied in autoshaping with rats. Experiment 1 established that the two contexts used subsequently were easily discriminable and equally salient. In Experiment 2, independent groups of rats received acquisition training under partial reinforcement (PRF) or continuous reinforcement (CRF). Significant PREEs were observed whether extinction occurred in the same or in a different context. In Experiment 3, after PRF or CRF acquisition training, each group received extinction of the same conditioned stimulus in both the same and different contexts. PREEs were observed under both conditions, although extinction was accelerated after a contextual shift. These results were discussed in relation to the role of mediational states in the PREE.     

Fixed-ratio reinforcement of spaced responding

Responses by rats were reinforced with food under a second-order schedule involving fixed-ratio reinforcement of temporally spaced responses. Requirements of 20, 8, and 3 responses were examined. The typical characteristic of spaced responding was maintained under the ratio schedules: interresponse time distributions were similar to those typically seen, and were not noticeably affected by the ratio value. Comparison of total response rate, correct response rate, and accuracy showed correct response rate to be the most consistently affected by changes in the ratio value. Substantial evidence of schedule control was seen only for correct responses. Incorrect response records were erratic, but rates generally declined as reinforcement was approached. Correct response records were characterized by increasing rate as reinforcement was approached. It was suggested that the pattern of fixed-ratio performance revealed may be affected by the behavioral unit examined.     

Early extinction effects following intermittent reinforcement: Little evidence of extinction bursts

The occurrence of extinction bursts—transient increases in response rate in excess of those observed in baseline during the period immediately following discontinuation of reinforcement of a response—was examined. In Experiment 1, key pecking of pigeons was reinforced according to a multiple schedule in which a variable-ratio schedule alternated with an interval schedule in which the reinforcers were yoked to the preceding variable-ratio component. In Experiments 2 and 3, rats were screened such that the lever-press response rates of different rats maintained by variable-interval schedules were either relatively high or relatively low. Following these baseline conditions, in Experiments 1 and 2 responding was extinguished by eliminating the food reinforcer and in Experiment 3 by removing the response–reinforcer dependency. Responses immediately following extinction implementation were examined. Response increases relative to baseline during the first 20 min of a 324.75-min extinction session (Experiment 1) or during the first 30-min extinction session (Experiments 2 and 3) were rare and unsystematic. The results (a) reinforce earlier meta-analyses concluding that extinction bursts may be a less ubiquitous early effect of extinction than has been suggested and (b) invite further experimentation to establish their generality as a function of preceding reinforcement conditions.     

Effects of US-Presentation and CS-termination contingencies on avoidance extinction following partial and continuous reinforcement

The present study assessed the role of both the US-presentation (punishment) and CS-termination contingencies on the maintenance of the shuttlebox avoidance responding in gerbils following acquisition under either partial reinforcement (PR) or continuous reinforcement (AV). Following PR, a stronger relationship obtained between delay of CS termination CR frequency than was found between delay of punishment and extinction performance. Following AV training, however, delay of CS termination and delay of punishment were equally effective determinants of avoidance extinction. These results were interpreted in terms of both the enhanced efficacy of the CS-termination contingency, possibly due to its increased informational value, and the attenuation of punishment suppression in PR-trained Ss.     

Resistance to extinction in the goldfish following schedules of continuous and variable interval reinforcement

Four goldfish (Carassius auratus, comet) were reinforced with food when they intercepted a beam of light. Each fish performed on both CRF and VI 50-sec schedules. In subsequent extinctions, the CRF schedule produced more responses on the first day than did VI, but after the first day the post-CRF rate dropped much more rapidly. These results agree with those previously obtained in birds and mammals.     

Key pecking during extinction after intermittent or continuous reinforcement as a function of the number of reinforcers delivered during training.

Key pecking by 7 pigeons was established and maintained on a multiple variable-ratio variable-ratio (VR) schedule of food presentation. The schedule in one of the components was then changed to fixed-ratio (FR) 1 for a predetermined number of reinforcers. Both components were then changed to extinction (i.e., multiple extinction, extinction). This sequence was repeated a different number of times for each pigeon to determine the relation between the number of reinforcers delivered during each component of the multiple VR FR 1 schedule and the number of responses during extinction. For most pigeons, there were fewer responses during extinction in the presence of a stimulus recently correlated with FR 1, regardless of the number of reinforcers received. The ratio of the total responses in extinction in the former VR component to the total responses in the former FR 1 component increased as the number of reinforcers delivered during each component of the multiple schedule increased. Within-subject replications of the partial-reinforcement extinction effect generally occurred, and there were no overall reductions in the number of responses in extinction with repeated exposures to extinction.