摘要:

Pigeons received equal variable‐interval reinforcement during presentations of two line‐orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among compo

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-3

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Three approaches to the determination of behavioral stability were examined. In the first, a learning curve was fit to acquisition data (from Cumming and Schoenfeld, 1960), and the “experiment” stopped when the data approached sufficiently close to the theoretical asymptote. In the second, the data were analyzed for variability and linear and quadratic trend. In the third, the experiment was stopped when the magnitude of the daily changes in the data fell below a criterion. Accuracy was measured as deviation between the average value of the dependent variable when the experiment was stopped, and the average value over the last 100 sessions. The first approach was most accurate, but at the cost of requiring the most sessions and being the most difficult to apply. Both the second and third approaches provided acceptable criteria with a reasonable cost‐accuracy tradeoff. The second approach permits a continuous adjustment of the criteria to accommodate the variability intrinsic in the experimental paradigm. The third, nomothetic, approach also takes into account the decreasing marginal utility of extended training ses

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-17

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

In a series of three experiments the effects of variation in grain duration on automaintenance were evaluated. In the first experiment, key illumination was followed by grain only when pigeons did not peck the key. Each subject was exposed to 2‐, 4‐, and 8‐second feeder durations in blocks of 10 sessions. Subjects pecked on a high percentage of trials at all feeder durations. The mean peck latency was shorter in the 8‐second condition than in the two other conditions in five of six subjects. The conditional probability of pecking given successive keylight‐grain pairings did not increase as the number of pairings increased. The second experiment was identical to the first, except that key pecking had no scheduled consequence. Under these conditions, all three subjects showed substantial responding. The recorded measures showed no systematic relationship to feeder duration in this study. In the third experiment, two different stimuli were followed by feeder presentations of either identical (2‐ or 8‐second) or different (2‐ and 8‐second) durations within each session. Subjects tended to respond sooner and with a higher overall rate in the presence of the stimulus associated with the longer feeder duration only when different feeder durations were presented within the same session. This result was confirmed by direct observation of the pigeons. The results of these experiments suggest that the effects of varying grain duration may be small, compared to the effects of varying other variables. The results also suggest that the location as well as the frequency of pecking may be an important measure in the analysis of factors controlling the

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-27

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

In a concurrent‐chains procedure, pigeons chose between outcomes that differed in the rate of response‐independent delivery of food and electric shocks. The application of functional measurement techniques confirmed the matching relation—between choice and rate of reinforcement value—for two of three pigeons. Scale values of the outcomes were extracted for the two birds that conformed to matching, and the value of a single occurrence of shock per minute—in terms of negative food units—was estimated. A second experiment with concurrent chains provided a test of these parameter estimates. The close correspondence between predicted and obtained choice behavior found in Experiment II indicated that the estimates of outcome value were indeed reliable. Both experiments together support the contention that the effects on choice behavior of positive and aversive stimuli appear to be equal, though oppos

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-37

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

After pretraining with multiple variable‐interval avoidance schedules, two rats were exposed to a series of concurrent variable‐interval avoidance schedules. Responses on two levers cancelled delivery of electric shocks arranged according to two independent variable‐interval schedules. The ratio of responses and time spent on the two levers approximately matched the ratio of shocks avoided on each. Matching to the number of shocks received was not obtained. Concurrent variable‐interval avoidance can therefore be added to the group of positive and negative reinforcement schedules that can be expressed in the quantitative framework of the match

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-61

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Responding under fixed‐interval schedules usually generates either scalloped or break‐and‐run cumulative records. Earlier, it was generally accepted that the characteristic pattern was the scallop, but in recent years there has been an increasing emphasis on the break‐and‐run pattern. The break‐and‐run pattern has been shown quantitatively to provide a good fit of certain fixed‐interval patterns. In the present work, responding during fixed‐interval 1000‐second components of a multiple fixed‐interval 1000‐second fixed‐ratio 50 responses schedule was examined in two rhesus monkeys. Even after responding had started in an interval, there was a high tendency for responding to accelerate over subsequent 100‐second segments of the interval. In segments with responding, the rate increased from one segment to the next in 303 of 389 segments in one monkey and in 310 of 419 segments in the other. The size of the increase was substantial, the rate in the fifth segment after responding started being an average of 4.5 times higher than the rate in the first segment after responding started. Hence, the usual pattern of responding in individual intervals was of sustained and substantial acceleration, vindicating numerically the conclusion derived from inspection of the scalloped pattern

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-67

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Pigeons chose between fixed‐interval schedules of different durations presented in the terminal links of concurrent‐chains schedules. The pair of schedules was always in the ratio of 2:1, but the absolute duration of the fixed intervals varied. In one set of conditions, the different terminal‐link schedules were associated with different keylight stimuli (cued conditions). In a second set of conditions, the different terminal‐link schedules were associated with the same stimulus (uncued conditions). Results from the cued conditions replicated previous findings that preference for the shorter fixed‐interval schedule increased with fixed‐interval duration. Preferences in the uncued conditions were lower than in the corresponding cued conditions but also increased with fixed‐interval length. In addition, the degree of control under the uncued conditions was correlated with the extent to which the schedule during the terminal link was discriminated immediately upon entry into the terminal link. The pattern of results in both conditions was inconsistent with the notion that choice behavior matches relative immediacy of reinforcement. Reanalysis of previous evidence for matching (Chung and Herrnstein, 1967) showed that matching in fact did not occur, as the preferences of their subjects for the shorter of two delays also increased with the absolute size

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-77

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

On avoidance procedures, rats and pigeons typically show warmup effects, characterized by improving performance within sessions and loss of the improvement (“warmup decrement”) between sessions. Between‐session losses were examined by varying the time between periods of avoidance training. In one experiment, rats lived fulltime in conditioning chambers while intermission intervals were varied. In a second experiment, the animals lived in home cages between sessions; timeout intervals were introduced at midsession, producing recurrence of warmup in the second half‐session. In both experiments, the warmup decrements increased substantially as the timeout or intersession intervals were increased from zero to 30 minutes. With intervals of 60 or 120 minutes, the decrements approached or exceeded those obtained with intervals of a day or more. When avoidance was interposed between appetitive sessions, the appetitive responding was disrupted, but this seemed unrelated to the warmup or to the proficiency of avoidance. The warmup in avoidance shares characteristics with transient punishment effects, with the Kamin effect, and with habituation phenomena, but it is premature to assume that they reflect common pr

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-87

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

Four pigeons were trained on a matching‐to‐sample task in which reinforcers followed either the first matching response (fixed interval) or the fifth matching response (tandem fixed‐interval fixed‐ratio) that occurred 80 seconds or longer after the last reinforcement. Relative frequency distributions of the matching‐to‐sample responses that concluded intermatching times and runs of mismatches (intermatching error runs) were computed for the final matching responses directly followed by grain access and also for the three matching responses immediately preceding the final match. Comparison of these two distributions showed that the fixed‐interval schedule arranged for the preferential reinforcement of matches concluding relatively extended intermatching times and runs of mismatches. Differences in matching accuracy and rate during the fixed interval, compared to the tandem fixed‐interval fixed‐ratio, suggested that reinforcers following matches concluding various intermatching times and runs of mismatches influenced the rate and accuracy of the last few matches before grain access, but did not control rate and accuracy throughout the entire fixe

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-105

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY

摘要:

The purpose of this research was to investigate the phenomenon of misbehavior described by Breland and Breland (1961). Rats were trained to obtain ball‐bearings and drop them in a hole for food or water reinforcers. In confirmation of the Brelands' observation, many subjects were slow to deliver the balls, and frequently attempted to chew them before they were dropped. A series of four experiments, in which the same rats were used throughout, showed that delivery times tended to be longer with food than with water, and that these times increased when nylon balls were substituted. The effect of motivational level was investigated by varying both deprivation and amount of prefeeding; no effect on delivery time was detected, although other measures of performance were affected by motivational factors. Similar results were obtained in a final experiment that employed a new set of naive subjects. The studies demonstrated that misbehavior can be studied in an experimental situation, and the results supported an analysis in terms of competition between stimulus‐reinforcer and response‐reinforcer contingencies. The question of why such effects have not been reported in previous token reinforcer studies was unans

ISSN:0022-5002    

DOI:10.1901/jeab.1978.29-115

出版商:Blackwell Publishing Ltd    

年代:1978

数据来源: WILEY