摘要:

Responding maintained in rats under a variable‐interval 35‐sec food schedule was suppressed more by 60‐sec and 240‐sec fixed‐interval schedules of shock delivery than by 60‐sec and 240‐sec variable‐interval schedules of shock delivery. When the delivery of shock was preceded by a 5‐sec visual stimulus, little overall response suppression was found with either fixed‐interval or variable‐interval schedules. In a third experiment, the percentage of occasions on which a cue preceded each shock delivery was varied from 0% to 100%. For the fixed‐interval shock condition, the most suppression occurred with the 0% treatment, the least with 100%, and an intermediate amount with the 50% treatment. For the variable‐interval groups, the most suppression occurred in the 50% condition, the least in the 100% group, and an in

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-101

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Pigeons responded in a two‐key situation. Responses on the right key (food key) were reinforced with food presentation on a response‐initiated fixed‐interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed‐ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food prese

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-113

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Cebus albifronsmonkeys received electrical stimulation of the hindlimbs over a wide range of intensities. On trials signalled by a blue light, the animals were permitted to escape shock by pressing a disc, or shock was terminated after 8 sec (free escape). Escape force (disc pressure) was found to increase as stimulation intensity increased well beyond escape threshold, while shock duration curves reached plateau at the mid‐range of intensities. The shock duration curves generated by free escape responses should be comparable to pain detection functions obtained by similar operations in humans, and the curves were stable over months of testing, as is generally found in pain‐detection studies. On trials signalled by a red light, the animals received intense tail shock immediately after escape responses (punished escape), or, if they endured leg shock for 8 sec without escaping, then they could avoid tail shock with a panel press. The shock duration curves generated by punished escape responses should be comparable to pain tolerance functions as defined for human subjects, and the escape thresholds were considerably higher on red‐light trials. As in human studies, the tolerance curves were not stable over repeated testing sessions, and some feature of the paradigm forced a progression toward extremely high levels of tole

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-125

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

The effects of drugs were studied in pigeons whose responses were punished with electric shock during one component of a multiple fixed‐interval 5‐min fixed‐interval 5‐min schedule of food presentation. Most of the drugs analyzed for rate‐dependent effects increased low rates of both punished and unpunished responding, while increasing higher rates less, or decreasing them; however, low rates of punished responding sometimes were increased more by pentobarbital, diazepam, and chlordiazepoxide than were matched rates of unpunished responding. In contrast,d‐amphetamine and chlorpromazine usually increased low rates of unpunished responding more than matched rates of punished responding. These two drugs also decreased high rates of unpunished responding less than they decreased high rates of punished responding. Thus, the effects of drugs on punished responding depend on the control rate of punished responding; however, the rate‐dependent effects of drugs on punished responding are not always the same as they are for unpunish

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-133

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Six pigeons were trained on a variety of concurrent fixed‐interval fixed‐interval schedules. Matching between response or time ratios and ratios of obtained numbers of reinforcements was found for eight of 12 schedules studied. Cumulative records showed both typical burst‐and‐break patterns and also atypical response patterns in which response rate was constant between reinforcements on a schedule. Matching occurred only when the same pattern was present on both concurrent schedules. When different response patterns were generated by the two schedules, the pigeons consistently emitted fewer responses to the shorter fixed‐interval than required by

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-147

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Key pecks by six pigeons were reinforced on concurrent fixed‐interval fixed‐ratio schedules. The value of the fixed‐interval was held constant at 4 min while the fixed‐ratio varied from 25 to 450 responses. All of the pigeons responded on, with pecks reinforced under, both of the schedules over most of the concurrent pairings, and four of the six distributed responses between the schedules such that matching was obtained between the proportions of responses and reinforcements. Previous studies using concurrent variable‐interval schedules have shown that when response‐reinforcement matching occurs, a comparable match of time to reinforcement proportions is obtained. In the present study, time devoted to each response alternative was measured from the first response on that alternative to a subsequent response on the other alternative. Using that measure, large differences existed in the local rates of responding on the two schedules, and a time‐reinforcement match was not produced. These results indicate that in a situation where response‐reinforcement and time‐reinforcement matching are incompatible, the measurement of response proportions is the better means of evaluating the effects

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-155

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

In Experiment I, pigeons were given equal reinforcement (variable‐interval 1‐min) for responding during randomized presentations of eight line‐orientation stimuli. Then, only responding in the vertical orientation was reinforced. Stable generalization gradients soon formed and persistent behavioral and local (transient) contrast effects appeared. Local contrast effects were not a function of relative reinforcement frequency or of any other variable known to produce contrast. Instead, they were related to average response rates associated with each stimulus. Experiment II showed that local contrast effects represent increases and decreases in response rates relative to baseline responding, and that these effects are relative; a given stimulus might enhance responding during a subsequent presentation of one stimulus, but depress responding when followed by another. These data indicate that discrimination learning is not adequately described as the acquisition of excitatory properties by some stimuli and inhibitory properties by others. A more adequate account implies that stimuli exert both excitatory and inhibitory effects related to their

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-167

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Twelve pigeons were trained on matching‐to‐sample using either a 0‐, 5‐, 15‐, 25‐, or 60‐sec intertrial interval. Eight of these 12 pigeons were given one of the following intertrial interval changes: 0 to 60, 0 to 5, 5 to 0, 60 to 0, 15 to 25, 5 to 15, 60 to 5, 5 to 1, 1 to 5, 1 to 25, and 25 to 1 sec. Most intertrial interval changes were repeated at least once. The 0‐sec intertrial interval subjects failed to match beyond chance levels, while other intertrial interval values resulted in matching acquisition. Changes from 0 sec to other intertrial interval values increased and changes to 0 sec decreased matching performance. Changes to intertrial interval values other than 0 sec resulted in little change in matching accuracy once stable performance ha

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-181

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-187

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0022-5002    

DOI:10.1901/jeab.1973.19-191

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY