摘要:

Local patterns of responding were studied when pigeons pecked for food in concurrent variable‐interval schedules (Experiment I) and in multiple variable‐interval schedules (Experiment II). In Experiment I, similarities in the distribution of interresponse times on the two keys provided further evidence that responding on concurrent schedules is determined more by allocation of time than by changes in local pattern of responding. Relative responding in local intervals since a preceding reinforcement showed consistent deviations from matching between relative responding and relative reinforcement in various postreinforcement intervals. Response rates in local intervals since a preceding changeover showed that rate of responding is not the same on both keys in all postchangeover intervals. The relative amount of time consumed by interchangeover times of a given duration approximately matched relative frequency of reinforced interchangeover times of that duration. However, computer simulation showed that this matching was probably a necessary artifact of concurrent schedules. In Experiment II, when component durations were 180 sec, the relationship between distribution of interresponse times and rate of reinforcement in the component showed that responding was determined by local pattern of responding in the components. Since responding on concurrent schedules appears to be determined by time allocation, this result would establish a behavioral difference between multiple and concurrent schedules. However, when component durations were 5 sec, local pattern of responding in a component (defined by interresponse times) was less important in determining responding than was amount of time spent responding in a component (defined by latencies). In fact, with 5‐sec component durations, the relative amount of time spent responding in a component approximately matched relative frequency of reinforcement in the component. Thus, as component durations in multiple schedules decrease, multiple schedules become more like concurrent schedules, in the sense that responding is affected by allocation of time rather than by local pattern of respo

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-309

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Two experiments investigated the extent to which response contingencies influence the choice between two schedules of reinforcement by exposing pigeons to a concurrent‐chains procedure in which reinforcers in one terminal link were response‐independent, and in the other terminal link, response‐dependent. In Experiment 1, the pigeons were indifferent between an aperiodic, response‐independent schedule and an aperiodic, response‐dependent schedule that required a minimum rate of responding. This finding limits the generality of a required‐rate contingency as a determinant of choice, which contingency had been previously demonstrated in a context of periodic reinforcement to evoke preference for an alternate schedule. In Experiment 2, the pigeons preferred a periodic, response‐independent schedule to a periodic, response‐dependent schedule that shared a feature with a required‐rate schedule: there was a requirement to respond early in the interreinforcement interval, when responding produced reinforcement only later. The results of the two experiments suggest the following general interpretation: pigeons prefer a second schedule to the extent that the response contingencies of the first schedule must be satisfied during discriminable periods of

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-339

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Choice between a signalled shock schedule and an unsignalled one was examined at various shock intensities. Three rats were given the opportunity to change from the unsignalled schedule to the signalled one at intensity values between 0.15 mA and 1.0 mA. Steps were usually 0.15 mA and both ascending and descending series were given. For two other rats, shock intensity increased from 0.20 mA to 1.0 mA in 0.20‐mA increments; for two additional rats, shock intensity was first 3.0 mA and was then reduced to 1.0 mA. Subjects tended to remain in the unsignalled schedule at the lower shock intensities, but spent most of each session under the signalled schedule at the higher intensities (1.0 mA and 3.0 mA). In addition, the time spent in the signalled schedule tended to vary systematically with shock intensity over at least part of the range of intensity values. It was concluded that the relationship between shock intensity and choice behavior is similar to the relationship between intensity and behavior in procedures involving avoidance, escape, and punishmen

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-349

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-356

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Three experiments evaluated whether behavioral similarity provided by an adult could serve as a reinforcer for the modelling behavior of four preschoolers. In each experiment, sessions consisted of two kinds of trials: (1) experimenter‐modelled trials, when the child's imitation of modelled motor responses was reinforced with praise and tokens, and (2) child‐modelled trials when experimenter imitation of child‐modelled responses was contingent upon the child's modelling one of three alternative responses: operation of a ball, horn, or clicker. Experiment I showed that the children consistently modelled whichever responses the experimenter imitated. Experiment II determined whether that performance was due to differences in the amount of experimenter behavior following imitatedversusnonimitated child models or to experimenter imitation. Neither reducing nor increasing the amount of experimenter behavior following the children's nonimitated models altered their modelling of imitated responses. Experiment III evaluated whether experimenter imitation of child models was a reinforcer because the child's imitative responses were reinforced on experimenter‐modelled trials. In Experiment III, the children's nonimitation of experimenter‐models was reinforced with praise and tokens on a schedule of differential reinforcement of other behavior, yet they continued to model experimenter‐imitated responses on child‐modelled trials. These results indicate behavioral similarity was reinforcing, though no conditioning history through which it acquired that function was

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-357

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Two male, albino rats were trained on a two‐valued, self‐paced, discrete‐trials auditory discrimination. In the presence of a high‐intensity stimulus (90 decibels SPL, 4 kiloHertz), response A was reinforced; in the presence of a low‐intensity stimulus (50 decibels SPL, 4 kiloHertz), response B was reinforced. When discrimination performance was asymptotic, stimuli intermediate in intensity were presented with the training stimuli in a maintained generalization paradigm. Generalization gradients were derived from the relative frequencies of response A in the presence of each stimulus. A relative frequency of 0.50 was then determined and used as the bisection point of the intensity interval defined by the 90‐ and 50‐decibel stimuli. The bisection point varied with the distribution of the stimuli presented in generalization. This effect was similar to context effects seen in human

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-369

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Three groups of rats received either 8, 23, or 53 sessions of multiple variable‐interval variable‐interval baseline training before being shifted to a multiple extinction variable‐interval schedule. The rate of responding during the unaltered component was higher for the groups shifted to multiple extinction variable‐interval than for control groups remaining on multiple variable‐interval variable‐interval (positive contrast). Furthermore, when the multiple variable‐interval variable‐interval schedule was re‐instated, stable negative contrast was found in the groups that had received 23 or 53 baseline sessions, but not for the group that had received only eight sessions. Positive and negative contrast were also demonstrated in the eight and 23‐session groups when the multiple extinction variable‐interval and multiple variable‐interval variable‐interval schedules were re‐administered in further phases of the experiment. These results suggest that both positive and negative behavioral contrast can be obtained reliably in a sp

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-377

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Failures to obtain a peak‐shift and inhibitory stimulus control following massed extinction in the presence of intra‐ and interdimensional stimuli confirm earlier results reported by Honig, Thomas, and Guttman (1959) and by Weisman and Palmer (1969). Peak‐shifts and inhibitory stimulus control were observed when any of the following procedures intervened for 3 min between massed extinction and generalization testing: (1) S+ presented, responding reinforced; (2) S+ presented, responding not reinforced; or, (3) noncontingent food presented in the presence of a dark key. Behavioral contrast was shown not to be a necessary antecedent for the occurrence of peak‐shift or inhibitory stimulus

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-385

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Lever pressing by rhesus monkeys was maintained by morphine injections during four equally spaced sessions each day. During other periods, lever pressing was maintained by timeout from a continuous naloxone infusion (escape), or by timeout from a stimulus that preceded naloxone injections, or termination of the injections (avoidance‐escape). As naloxone dose increased in the escape procedure, response rate increased to a maximum and then decreased. In the avoidance‐escape procedure, response rate generally increased as naloxone dose increased, but the changes in rate were small compared to the escape procedure. Substitution of saline for naloxone in the escape procedure led to very low response rates within three sessions. In the avoidance‐escape procedure, rate decrements produced by saline substitution appeared to be related to the behavioral history of the monkey. Previous escape experience led to more rapid decreases in responding when saline was introduced, whereas responding was maintained for 15 sessions in a monkey without prior escape conditioning. Morphine pretreatment produced comparable, dose‐dependent decreases in response rates in both procedures. The rate‐decreasing effects of morphine were exacerbated when no naloxone was delivered in the escape

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-415

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

Pigeons obtained food by making four responses on three keys in a specified sequence,e.g., left, right, center, right. Under the “tandem‐learning” condition, all three keys were the same color throughout the response sequence, and the sequence was changed from session to session. After total errors per session (overall accuracy) and within‐session error reduction (learning) had stabilized, the effects of varying doses of phenobarbital and chlordiazepoxide were assessed. For comparison, the drug tests were also conducted under a “performance” condition, in which the response sequence was the same from session to session, and under corresponding “chain‐learning” and “chain‐performance” conditions, where different colored keylights were associated with the response sequence. Under all four baseline conditions, the largest dose of each drug impaired overall accuracy. Under the two learning conditions, the error rate decreased across trials within each session, but the degree of negative acceleration was less in the drug sessions than in the control sessions. In contrast, under the two performance conditions, the error rate was relatively constant across trials, but was higher in the drug sessions than in the control sessions. Of the four baselines, the chain‐learning condition was the most sens

ISSN:0022-5002    

DOI:10.1901/jeab.1975.23-429

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY