Relationship between response rate and reinforcement frequency in variable-interval schedules: II. Effect of the volume of sucrose reinforcement

Three rats were exposed to variable-interval schedules specifying a range of different reinforcement frequencies, using three different volumes of .32 molar sucrose (.10, .05, and .02 milliliters) as the reinforcer. With each of the three volumes, the rates of responding of all three rats were increasing, negatively accelerated functions of reinforcement frequency, the data conforming closely to Herrnstein's equation. In each rat the value of the constant K_H, which expresses the reinforcement frequency needed to obtain the half-maximal response rate, increased with decreasing reinforcer volume, the values obtained with .02 milliliters being significantly greater than the values obtained with .10 milliliters. The values of the constant R_max, which expresses the theoretical maximum response rate, were not systematically related to reinforcer volume. The effect of reinforcer volume upon the relationship between response rate and reinforcement frequency is thus different from the effect of the concentration of sucrose reinforcement: In a previous experiment (Bradshaw, Szabadi, & Bevan, 1978) it was found that sucrose concentration influenced the values of both constants, R_max increasing and K_H decreasing with increasing sucrose concentration.     

ASSESSING AND TRAINING TEACHERS IN THE GENERAUZED USE OF BEHAVIOR MODIFICATION WITH AUTISTIC CHILDREN1

This study investigated the feasibility of developing reliable, valid criteria for measuring and training the skills necessary to teach autistic children. The behaviors of 11 teachers and 12 autistic children were recorded in a series of different teaching situations. Teacher-training was initiated at different times for different teachers. The results showed: (1) it was possible to assess empirically whether a teacher was correctly using defined behavior-modification techniques; (2) generally, for any given session, systematic improvement in the child's behavior did not occur unless the teacher working in that session had been trained to use the techniques to a high criterion; (3) all 11 teachers were rapidly trained to use these techniques; and (4) the teachers learned generalized skills effective with a variety of children and target behaviors.     

Multiple and concurrent schedule performance: independence from concurrent and successive schedule contexts

Six pigeons were trained on multiple variable-interval schedules and performance was measured in the presence or absence of another variable-interval schedule (the common schedule) arranged concurrently with both components. Manipulations included varying the rate of reinforcement on the common schedule, leaving the common schedule unchanged while the components of the multiple schedule were varied, varying the multiple schedule components in the absence of the common schedule, and varying one component of the multiple schedule while the other component and the common schedule were unchanged. The normal rate-increasing and rate-decreasing effects of reinforcement rate increase were found, except that changing one multiple schedule component did not affect the response rate in the successively available common schedule component. Both concurrent and multiple schedule performance undermatched obtained reinforcement-rate ratios, but the degree of undermatching in multiple schedules was reliably greater. Allocation of responses between multiple schedule components was unaffected by the concurrent availability of reinforcement, and allocation of responses between concurrent schedules was unaffected by the successive availability of different reinforcement rates.     

Session duration and the VI response function: Within-session prospective and retrospective effects

Two experiments examined the effects of session duration on responding during simple variable-interval schedules. In Experiment 1, rats were exposed to a series of simple variable-interval schedules differing in both session duration (10 min or 30 min) and scheduled reinforcement rate (7.5 s, 15 s, 30 s, and 480 s). The functions relating response rate to reinforcement rate were predominantly monotonic for the short (10-min) sessions but were predominantly bitonic for the long (30-min) sessions, when data from the entire session were considered. Examination of responding within sessions suggested that differences in the whole-session data were produced by a combination of prospective processes (i.e., processes based on events scheduled to occur later in the session) and retrospective processes (i.e., processes based on events that had already occurred in the session). In Experiment 2, rats were exposed to a modified discrimination procedure in which pellet flavor (standard or banana) predicted session duration (10 min or 30 min). All rats came to respond faster during the short (10-min) sessions than during the first 10 min of the long sessions. As in Experiment 1, the results seemed to reflect the simultaneous operation of both prospective and retrospective processes. The results shed light on the recent controversy over the form of the variable-interval response function by identifying one variable (session duration) and two types of processes (prospective and retrospective) that influence responding on these schedules.     

Response deprivation, reinforcement, and economics

Reinforcement of an instrumental response results not from a special kind of response consequence known as a reinforcer, but from a special kind of schedule known as a response-deprivation schedule. Under the requirements of a response-deprivation schedule, the baseline rate of the instrumental response permits less than the baseline rate of the contingent response. Because reinforcement occurs only if the schedule deprives the organism of the contingent response, reinforcement cannot result from any intrinsic property of the contingent response or any property relative to the instrumental response. Two typical effects of response-deprivation schedules—facilitation of the instrumental response and suppression of the contingent response—are discussed in terms of economic concepts and models of instrumental performance. It is suggested that response deprivation makes the contingent response function as an economic good, the instrumental response as currency.     

The effect of increased response requirements on discriminative performance of the domestic hen in a visual acuity task.

Six domestic hens were trained in a spatial discrimination task. A controlled reinforcement procedure insured that the ratio of scheduled and obtained reinforcement remained equal. Gray stimuli and gratings ranging in spatial frequency from 1 to 10 cycles per millimeter were presented in seven descending series of probes. The response requirement to the sample key was varied from fixed ratio 1 to fixed ratio 40 in seven experimental conditions. An increase in response requirements from fixed ratio 1 to fixed ratio 5 and fixed ratio 10 resulted in significantly higher accuracy at discriminable grating values. Further increases in response requirements did not consistently improve performance. Generally, response biases increased and occasionally became extreme for probes at finer gratings with increased response requirements.     

从归因理论的角度探讨我国大学生的社会性评价

本文采用归因理论研究方法测试我国大学生对五种生理病症和五种心理、行为引起的疾患或缺陷的责任归因、情感反应和帮助行为的关系,借以探讨我国大学生对疾患者的社会评价的特点和研究方法。研究结果表明这是一种可用于研究社会性评价的方法。同时,这项研究也体现了我国大学生对某些社会性评价的特点。     

驾驶员的动态反应时研究

本研究应用DFY-1型动态反应时测试仪,以解放CA10B 型卡车为实验用车,结合日常运输任务,对三种年龄组(20—29岁、30—39岁、40—49岁)的30名驾驶员,在三种车速(静态,30公里/小时及50公里/小时)条件下的反应时、动作时及制动反应时进行了测试。结果表明:车速对驾驶员的反应时及制动反应时有显著影响,而对动作时则无显著影响;驾驶员的年龄对反应时、动作时及制动反应时均无显著影响.本研究结果为加强驾驶员的安全教育与管理,控制车速提供了佐证。更高车速条件下驾驶员的反应时特点尚待进一步研究。     

Teaching a chained task with a simultaneous prompting procedure

Simultaneous prompting, a type of antecedent prompt and test procedure, was used to teach the chained task of making juice from a frozen concentrate using a pictorial recipe to four elementary-aged students with moderate intellectual disabilities. Using a multiple probe design, all students acquired the task and maintained the behavior with at least 85% accuracy up to 60 days after training was terminated. In addition, students generalized the skill across settings and materials. The students' ability to expressively identify the words shown on the recipe cards was tested prior to and after training. Although not directly trained, three of the four students increased their ability to read the words.     

Conditioned reinforcement value and choice.

The delay-reduction hypothesis of conditioned reinforcement states that the reinforcing value of a food-associated stimulus is determined by the delay to primary reinforcement signaled by the onset of the stimulus relative to the average delay to primary reinforcement in the conditioning situation. In contrast, most contemporary models of conditioned reinforcement strength posit that the reinforcing strength of a stimulus is some simple function only of the delay to primary reinforcement in the presence of stimulus. The delay-reduction hypothesis diverges from other conditioned reinforcement models in that it predicts that a fixed-duration food-paired stimulus will have different reinforcing values depending on the frequency of its presentation. In Experiment 1, pigeons' key pecks were reinforced according to concurrent-chains schedules with variable-interval 10-second and variable-interval 20-second terminal-link schedules. The initial-link schedule preceding the shorter terminal link was always variable-interval 60 seconds, and the initial-link schedule requirement preceding the longer terminal link was varied between 1 second and 60 seconds across conditions. In Experiment 2, the initial-link schedule preceding the longer of two terminal links was varied for each of three groups of pigeons. The terminal links of the concurrent chains for the three groups were variable-interval 10 seconds and 20 seconds, variable-interval 10 seconds and 30 seconds, and variable-interval 30 seconds and 50 seconds. In both experiments, preference for the shorter terminal link was either a bitonic function or an inverse function of the initial-link schedule preceding the longer terminal-link schedule. Consistent with the predictions of the delay-reduction hypothesis, the relative values of the terminal-link stimuli changed as a function of the overall frequency of primary reinforcement. Vaughan's (1985) melioration model, which was shown to be formally similar to Squires and Fantino's (1971) delay-reduction model, can be modified so as to predict these results without changing its underlying assumptions.