摘要:

Operant temporal discrimination learning was investigated in goldfish. In the first experiment, there was a fixed daily change in illumination. Eight subjects were trained to operate a lever that reinforced each press with food. The period during which responses were reinforced was then progressively reduced until it was 1 hr in every 24. The final 1‐hr feeding schedule was maintained over 4 weeks. The feeding period commenced at the same time each day throughout. The food dispensers were then made inactive, and a period of extinction ensued for 6 days. The pattern of responding suggested that the fish were able to exhibit temporal discrimination in anticipation of feeding time. This pattern of responding persisted for a limited number of days during the extinction procedure. The second experiment produced evidence that operant temporal discrimination could develop under continuous illuminatio

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-1

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Under a psychophysical trials procedure, pigeons were presented with a red light of one duration followed by a green light of a second duration. Eight geometrically spaced base durations were paired with one of four shorter and four longer durations as the alternate member of a duration pair, with different pairs randomly intermixed. One choice was reinforced if red had lasted longer than green, and a second choice was reinforced if green had lasted longer. Performance was compared when all the base durations and their pair members were included (entire‐range condition) or when only the four longest base durations and their comparison durations (restricted‐range condition) were used. Discrimination sensitivity decreased for longer duration pairs under both conditions, supporting a memory‐based account. Sensitivity was lower under the restricted‐range condition. Under both conditions, a bias to report “green as longer” increased as the second green duration increased. Bias changed as a matching function of the green‐duration predictiveness of the correct choice. The results are related to a quantitative model of timing and remembering propos

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-15

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Five pigeons served as subjects in an experiment that examined the effects of variable as opposed to fixed delays on preference in a self‐control paradigm (choice between larger, more delayed and smaller, less delayed reinforcers). Nonindependent concurrent variable‐interval schedules were used to measure choice. When delays to the larger, more delayed reinforcers were variable as opposed to fixed, the subjects showed an increased preference for that alternative (the self‐control alternative). A series of regressions revealed that the hyperbolic decay model and incentive theory provided poor fits to the data, but a modified version of the generalized matching law provided an adequate fit. Together, consistent with a general prediction made by discounting models, the data supported the conclusion that variable delays can increase self‐control. However, specific discounting models were not able to explain the present da

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-33

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Four squirrel monkeys responded daily under a fixed‐interval 5‐min or 8‐min schedule of food‐pellet delivery. Cocaine (0.03 to 1.7 mg/kg) and saline were injected before occasional daily sessions (acute administration). Some doses of cocaine produced substantial overall increases in response rate for 3 of the subjects; effects were less substantial for the remaining subject, who exhibited modest increases in response rate early in the session and during the middle portion of the intervals. A dose that increased response rate when administered acutely was then administered before each session (chronic administration). Chronic administration resulted in a reduction in the increases in response rate seen under acute administration for all s

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-45

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Changes in respiration associated with schedule‐controlled behavior were determined in seated rhesus monkeys prepared with a pressure‐displacement head plethysmograph for monitoring ventilation continuously during behavioral experiments. Subjects were trained to press a lever under fixed‐ratio 40 and fixed‐interval 300‐s schedules of stimulus termination. Episodic increases in ventilation were closely associated with periods of responding under both schedules. Recurring episodes of increased ventilation occurred during fixed‐ratio responding, and were separated by brief 10‐s timeouts during which ventilation decreased. Under the fixed‐interval schedule, both ventilation and response rate typically increased as the 300‐s interval elapsed. The effects of cocaine, caffeine, and two adenosine agonists, 5′‐N‐ethylcarboxamidadenosine (NECA) and 2‐(carboxyethylphenylamino)adenosine‐5′‐carboxamide (CGS 21680), on behavior and respiration were determined using a cumulative‐dosing procedure. Drug‐induced suppression of behavior eliminated the episodic increases in ventilation during the performance components of both schedules. Schedule‐related increases in ventilation were compared to those produced by elevated levels of CO2in inspired air. Exposure to 4% CO2mixed in air increased ventilation in all subjects, and the combined effects of CO2exposure and schedule‐controlled responding on respiration appeared to be additive. The results suggest that behavioral activities may increase ventilation through increased metab

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-57

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

In three experiments, 8 human subjects participated in a study of the effects of smoked marijuana on progressive‐interval schedule performance. A two‐component chained progressive‐interval fixed‐interval schedule of point delivery was used. In the progressive‐interval component, the interval length began at 20 s and increased either geometrically or arithmetically (by either 20 s, 40 s, 80 s, 100 s, or 160 s) on each subsequent interval. After this interval elapsed, a single button press produced the fixed‐interval component, with a total of five reinforcers of varying magnitude ($0.05, $0.20, or $0.40) available on a fixed‐interval 20‐s schedule. After the five reinforcer deliveries, the schedule returned to the initial progressive‐interval component. Several relationships were found among rates of responding, postreinforcement pauses, and drug administration in the progressive‐interval component: (a) Postreinforcement pauses increased as the temporal requirements of the progressive‐interval schedule increased; (b) rates of responding during successive progressive‐interval components rapidly decreased to low rates of responding after the first few progressions; (c) postreinforcement pauses decreased systematically as dose of smoked marijuana increased; and (d) rates of responding increased after smoking active marijuana but not after smoking placebo cigarettes. Results are discussed in the context of behavioral control and relevance to other studies that have investigated the effects of smoked marijuana

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-73

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Five pigeons were trained on a procedure that has been used as a laboratory analogue to natural patch residence. Trials commenced with two responses available. One of these might provide a reinforcer if the patch was a prey patch; the other ended the residence time in the patch and, after a fixed travel time in blackout, produced another patch that might or might not provide a reinforcer. Patch residence also ended, and was followed by the same travel time, after a reinforcer was obtained or after a fixed maximum time was spent in the patch. The dependent variable was patch residence time, from the commencement of the patch to the time at which the subject emitted a response to exit from the patch or until the maximum patch residence time had elapsed. In Parts 1 to 3, the duration of the imposed travel time was varied from 0.25 to 16 s at three different probabilities (.05, .1, and .2) of food per second (λ) in prey patches. As reported in previous research, both increasing travel time and decreasing probabilities of reinforcers per second increased patch residence time. In Parts 4 to 7, the probability of prey trials (p) was varied in an irregular order from .1, through .2, .5, and .7, to .9 for different combinations of λ and travel time. Respectively, these were in Part 4, .05 per second and 0.25 s; in Part 5, .05 per second and 16 s; in Part 6, .2 per second and 0.25 s; and in Part 7, .2 per second and 16 s. A previously offered model, based on optimization assumptions, substantially and consistently underpredicted patch residence time. However, a modification of that model, which assumes that the subjects could not accurately discriminate the residence time that provided the minimum interreinforcer interval, described the data well. The same model also described previously reported residence times in a different species with a uniform distribution of prey‐arrival ti

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-89

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Pigeons' key pecking was reinforced by food delivered by several fixed‐interval, variable‐ratio, and differential‐reinforcement‐of‐low‐rate schedules. Rate of responding, number of responses per reinforcer, length of postreinforcement pause, running response rate, and the time required to collect an available reinforcer changed systematically within sessions when the schedules provided high rates of reinforcement, but usually not when they provided low rates. These results suggest that the factors that produce within‐session changes in responding are generally similar for different schedules of reinforcement. However, a separate factor may also contribute during variable‐ratio schedules. The results question explanations for within‐session changes that are related solely to the passage of time, to responding, and to one interpretation of attention. They support the idea that one or more factors related to reinforc

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-109

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

In the first two experiments, subjects' choices to earn points (exchangeable for money) either by competing with a fictitious opponent or by not competing were studied. Buskist, Barry, Morgan, and Rossi's (1984) competitive fixed‐interval schedule was modified to include a second response option, a noncompetitive fixed‐interval schedule. After choosing to enter either option, the opportunity for reinforcers became available after the fixed‐interval's duration had elapsed. Under the no‐competition condition, points were always available after the interval had elapsed. Under the competition condition, points were available based on a predetermined probability of delivery. Experiments 1 and 2 examined how reinforcer probabilities and reinforcer magnitudes affected subjects' choices to compete. Several general conclusions can be made about the results: (a) Strong preferences to compete were observed at high and moderate reinforcer probabilities; (b) competing was observed even at very low reinforcer probabilities; (c) response rates were always higher in the competition component than in the no‐competition component; and (d) response rates and choices to compete were insensitive to reinforcer‐magnitude manipulations. In Experiment 3, the social context of this choice schedule was removed to determine whether the high levels of competing observed in the first two experiments were due to a response preference engendered by the social context provided by the experimenters through instructions. In contrast to the first two experiments, these subjects preferred the 60‐s fixed‐interval schedule (formerly the no‐competition option), indicating that the instructions themselves were responsible for the preference to compete. This choice paradigm may be useful to future researchers interested in the effects of other independent variables (e.g., drugs, social context, instructions) on com

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-133

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

An apparatus was developed to study social reinforcement in the rat. Four Long‐Evans female rats were trained to press a lever via shaping, with the reinforcer being access to a castrated male rat. Responding under a fixed‐ratio schedule and in extinction was also observed. Social access was found to be an effective reinforcer. When social reinforcement was compared with food reinforcement under similar conditions of deprivation and reinforcer duration, no significant differences were obser

ISSN:0022-5002    

DOI:10.1901/jeab.1994.62-149

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY