摘要:

Emitting a certain response and waiting for a specified time without making that response had the same consequence. In Experiment 1, food‐deprived pigeons were as likely to wait as to respond only if waiting provided food at a much higher frequency than did pecking. In Experiment 2, the consequence for humans was a brief light flash and tone. People were not biased for responding over waiting. Instead, their choices suggested crude payoff maximization. In Experiment 3, pigeons again obtained food, but they were not food deprived and could eat freely at each opportunity. Their behavior was more like that of the humans of Experiment 2 than that of food‐deprived pigeons given small quantities of food at each feeding opportunity. The three experiments together showed that biases for responding over waiting were neither inherent characteristics of species nor inevitable outcomes of particular schedules. Choice between active search and waiting depended on ecological‐motivational factors even when species and schedules were held con

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-433

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Three experiments examined adult humans' choices in situations with contrasting short‐term and long‐term consequences. Subjects were given repeated choices between two time‐based schedules of points exchangeable for money: a fixed schedule and a progressive schedule that began at 0 s and increased by 5 s with each point delivered by that schedule. Under “reset” conditions, choosing the fixed schedule not only produced a point but it also reset the requirements of the progressive schedule to 0 s. In the first two experiments, reset conditions alternated with “no‐reset” conditions, in which progressive‐schedule requirements were independent of fixed‐schedule choices. Experiment 1 entailed choices between a progressive‐interval schedule and a fixed‐interval schedule, the duration of which varied across conditions. Switching from the progressive‐ to the fixed‐interval schedule was systematically related to fixed‐interval size in 4 of 8 subjects, and in all subjects occurred consistently sooner in the progressive‐schedule sequence under reset than under no‐reset procedures. The latter result was replicated in a second experiment, in which choices between progressive‐ and fixed‐interval schedules were compared with choices between progressive‐ and fixed‐time schedules. In Experiment 3, switching patterns under reset conditions were unrelated to variations in intertrial interval. In none of the experiments did orderly choice patterns depend on verbal descriptions of the contingencies or on schedule‐controlled response patterns in the presence of the chosen schedules. The overall pattern of results indicates control of choices by temporally remote consequences, and is consistent with versions of optimality theory that address perfo

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-445

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Steady and blinking white lights were projected on three nose keys arranged horizontally on one wall. The procedure was a conditional discrimination with a sample stimulus presented on the middle key and comparison stimuli on the side keys. Three rats acquired simultaneous “identity matching.” Accuracy reached 80% in about 25 sessions and 90% or higher after about 50 sessions. Acquisition progressed through several stages of repeated errors, alternation between comparison keys from trial to trial, preference of specific keys or stimuli, and a gradual lengthening of strings of consecutive trials with correct responses. An analysis of the acquisition curves for individual trial configurations indicated that the matching‐to‐sample performance possibly consisted of separate discrimi

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-471

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

The effects of income (money available to spend during the experimental session) on human choice were examined in a concurrent‐schedule arrangement. Subjects were 7 nicotine‐dependent smokers, and reinforcers were puffs on the subject's usual brand of cigarette (“own”) and puffs on a less preferred brand of cigarette with equal nicotine content (“other”). Across sessions, income varied and the price of the two reinforcers was held constant, with the other puffs one fifth the price of the own puffs. As income increased, consumption of own puffs increased while consumption of the less expensive other puffs decreased. These effects of income on choice were highly consistent across subjects. For some subjects, however, income had little effect on total puff consumption. Finally, an additional condition examined whether price and income manipulations would have functionally equivalent effects on choice by repeating an income condition in which the price of the other brand was increased. Although the increased price of the other puffs decreased their consumption in 4 subjects, 2 subjects showed increased consumption of the other puffs at the higher price. The results, when defined in economic terms, indicate that the own puffs were anormalgood (consumption and income are directly related), the other puffs were aninferiorgood (consumption and income are inversely related), and the direct relationship between consumption of the other puffs and their price is defined as aGiffen‐goodeffect. The latter result also suggests that for these 2 subjects, price and income manipulations had equivalent effects on choice. These results extend findings from previous studies that have examined the effects of income on choice responding to human subjects and drug reinforcers, and provide a framework for further experimental tests of the effects of income on human choice behavior. Methodological and theoretical implications for the study of choice and for behavioral pharmacology

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-483

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Two experiments explored the effects of two types of concurrent activity on human fixed‐interval performance. Eight adult subjects were given access to either reading material or a working television set across three fixed‐interval values (60 s, 300 s, and 600 s). During Experiment 1, 2 subjects produced “scalloped” patterns and reported no verbal regulation (e.g., counting) in the presence of the reading material, but shifted to low‐rate patterns and reported verbal regulation when the reading material was withdrawn. The 2 other subjects in Experiment 1 produced consistent low‐rate performances and reported verbal regulation during access to reading material. However, when these subjects were given access to a working television set, they produced scalloped patterns and reported no verbal regulation. During Experiment 2, 4 experimentally naive subjects showed consistent scalloped patterning and no verbal regulation across fixed‐interval values when they were allowed to watch television. When access to the television was denied, subjects reliably reported verbal regulation, and low‐rate patterns emerged. These behavioral effects focus our attention on the contingencies that control human performance on fixed‐i

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-501

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Using horses, we investigated the control of operant behavior by a tactile stimulus (the training stimulus) and the generalization of behavior to six other similar test stimuli. In a stall, the experimenters mounted a response panel in the doorway. Located on this panel were a response lever and a grain dispenser. The experimenters secured a tactile‐stimulus belt to the horse's back. The stimulus belt was constructed by mounting seven solenoids along a piece of burlap in a manner that allowed each to provide the delivery of a tactile stimulus, a repetitive light tapping, at different locations (spaced 10.0 cm apart) along the horse's back. Two preliminary steps were necessary before generalization testing: training a measurable response (lip pressing) and training on several reinforcement schedules in the presence of a training stimulus (tapping by one of the solenoids). We then gave each horse two generalization test sessions. Results indicated that the horses' behavior was effectively controlled by the training stimulus. Horses made the greatest number of responses to the training stimulus, and the tendency to respond to the other test stimuli diminished as the stimuli became farther away from the training stimulus. These findings are discussed in the context of behavioral principles and their relevance to the training of horse

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-521

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast‐acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed‐time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step‐down) or increasing from 15 to 45 s (step‐up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood‐interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step‐up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood‐interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions—discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-529

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

Bar presses by one group of rats were conditioned under a differential‐reinforcement‐of‐low‐rate reinforcement schedule immediately prior to conditioning under a fixed‐interval schedule. In a second group of rats, bar presses were conditioned first under a differential‐reinforcement‐of‐low‐rate schedule and then under a fixed‐ratio schedule prior to conditioning under a fixed‐interval schedule. Low response rates occurred under the fixed‐interval schedule only when it was immediately preceded by low‐rate conditioning. Otherwise, fixed‐interval responding was similar to responding under the fixed‐ratio schedule. This finding suggests that responses of laboratory animals are sensitive to immediate history, and, unlike human responses, are relatively insensitive to a history of low‐rate conditioning when it is fol

ISSN:0022-5002    

DOI:10.1901/jeab.1993.59-543

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY