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911.
    
We investigated how different numbers of responses prior to the presentation of a stimulus influenced preferences for the stimulus in three Japanese monkeys (Macaca fuscata). Monkeys were trained for two kinds of simultaneous discriminations that followed a high‐effort or a low‐effort response. In probe test trials, the stimulus that followed the high‐effort and the stimulus that followed the low‐effort response during discriminations were presented simultaneously. All monkeys chose stimuli that in training followed a low‐effort response. This result suggested that monkeys avoided stimuli that followed high‐effort responses because of the association between those stimuli and the preceding greater effort. The present result is consistent with our previous study conducted with humans, but contradicts analogous studies carried out with pigeons that reported either opposite results (i.e. pigeons preferred the stimuli after high‐effort) or non‐biased preferences. The differences between mammals and birds are discussed in terms of the lack of a successive negative contrast effect in birds.  相似文献   
912.
    
The current study examined the utility of multiple-exemplar training to teach children with autism to share. Stimuli from 3 of 4 categories were trained using a treatment package of video modeling, prompting, and reinforcement. Offers to share increased for all 3 children following the introduction of treatment, with evidence of skill maintenance. In addition, within-stimulus-category generalization of sharing was evident for all participants, although only 1 participant demonstrated across-category generalization of sharing. Offers to share occurred in a novel setting, with familiar and novel stimuli, and in the presence of novel adults and peers for all participants during posttreatment probes.  相似文献   
913.
    
We evaluated the effects of fixed-interval (FI), fixed-time (FT), and conjoint (combined) FI FT reinforcement schedules on the responding of 3 adults who had been diagnosed with schizophrenia. Responding on vocational tasks decreased for 2 of 3 participants under FT alone relative to FI alone. Responding under FI FT resulted in response persistence for 2 of 3 participants. Results have implications for the maintenance of desirable behavior, as well as for situations in which FT treatment has been implemented for problem behavior and problem behavior is nevertheless reinforced by caregivers.  相似文献   
914.
    
A brief training package consisting of modeling, rehearsal, and feedback was evaluated to train caregivers to use incidental teaching to teach 3 children with autism to request an item or activity. The training package improved correct implementation of the incidental teaching procedure by caregivers. In addition, probes indicated that caregivers could apply these skills to teach the child an additional skill.  相似文献   
915.
    
This study describes an unexpected behavioral process that influenced behavior during the teaching of concepts to a 4-year-old girl. The efficacy of and preference for three strategies that varied in teacher directedness were assessed in a multielement design and concurrent-chains arrangement, respectively. The strategy that involved the most teacher direction was most efficacious and preferred. In addition, embedded teacher prompts, common in child-led teaching procedures, functioned as a punisher for the child's toy play. Implications for designing effective and preferred teaching conditions are discussed.  相似文献   
916.
    
Previous research has shown that rats can learn matching-to-sample relations with olfactory stimuli; however, the specific characteristics of this relational control are unclear. In Experiment 1, 6 rats were trained to either match or nonmatch to sample in a modified operant chamber using common household spices as olfactory stimuli. After matching or nonmatching training with 10 exemplars, the contingencies were reversed with five new stimuli such that subjects trained on matching were shifted to nonmatching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new exemplars. In Experiment 2, 9 rats were trained with matching procedures in an arena that provided for 18 different spatial locations for comparison stimuli. Five subjects were trained with differential reinforcement outcomes and 4 with only one type of reinforcer. Differential outcomes and multiple exemplars facilitated learning, and there was strong evidence for generalization to new stimuli for most rats that acquired several conditional discriminations. Performances with novel samples were generally above chance, but rarely reached the high levels obtained during baseline with well-trained stimulus relations. However, taken together, the data from the two experiments extend previous work, show that rats can learn both match and nonmatch relations with different experimental protocols, and demonstrate generalization to novel sample stimuli.  相似文献   
917.
    
Twelve rats made repeated choices on an adjusting-delay schedule between a smaller reinforcer (A) that was delivered immediately after a response and a larger reinforcer (B) that was delivered after a delay which increased or decreased by 20% depending on the subject's choices in successive blocks of trials. In two phases of the experiment (100 sessions and 40 sessions), reinforcer sizes were selected which enabled theoretical parameters expressing the rate of delay discounting and sensitivity to reinforcer size to be estimated from the ratio of the indifference delays obtained in the two phases. Indifference delays, calculated from adjusting delays in the last 10 sessions of each phase, were shorter when the sizes of A and B were 14 and 25 μl of a 0.6 M sucrose solution than when they were 25 and 100 μl of the same solution. The ratio of the indifference delays was significantly smaller than that predicted on the basis of an assumed linear relation between reinforcer size and instantaneous reinforcer value, consistent with a previous proposal that this relation may be hyperbolic in form. Estimates of the rate of delay discounting based on the ratio of the two indifference delays (mean, 0.08 s(-1)) were similar to values obtained previously using different intertemporal choice protocols. Estimates of the size-sensitivity parameter (mean 113 μl) were similar to estimates recently derived from performance on progressive-ratio schedules. In both phases of the experiment, adjusting delays in successive blocks of trials were analyzed using the Fourier transform. The power spectrum obtained from individual rats had a dominant frequency that corresponded to a period of oscillation of the adjusting delay between 30 and 100 trial blocks (mean, 78). Power in the dominant frequency band was highest in the early sessions of the first phase and declined with extended training. It is suggested that this experimental protocol may have utility in neurobehavioral studies of intertemporal choice.  相似文献   
918.
    
Undergraduates were exposed to a series of reinforcement schedules: first, to a fixed-ratio (FR) schedule in the presence of one stimulus and to a differential-reinforcement-of-low-rate (DRL) schedule in the presence of another (multiple FR DRL training), then to a fixed-interval (FI) schedule in the presence of a third stimulus (FI baseline), next to the FI schedule under the stimuli previously correlated with the FR and DRL schedules (multiple FI FI testing), and, finally, to a single session of the multiple FR DRL schedule again (multiple FR DRL testing). Response rates during the multiple FI FI schedule were higher under the former FR stimulus than under the former DRL stimulus. This effect of remote histories was prolonged when either the number of FI-baseline sessions was small or zero, or the time interval between the multiple FR DRL training and the multiple FI FI testing was short. Response rates under these two stimuli converged with continued exposure to the multiple FI FI schedule in most cases, but quickly differentiated when the schedule returned to the multiple FR DRL.  相似文献   
919.
  总被引:1,自引:0,他引:1  
Despite its frequent use to assess effects of environmental and pharmacological variables on short-term memory, little is known about the development of delayed matching-to-sample (DMTS) performance. This study was designed to examine the dimensions and dynamics of DMTS performance development over a long period of exposure to provide a more secure foundation for assessing stability in future research. Six pigeons were exposed to a DMTS task with variable delays for 300 sessions (i.e., 18,000 total trials; 3,600 trials per retention interval). Percent-correct and log-d measures used to quantify the development of conditional stimulus control under the procedure generally and at each of five retention intervals (0, 2, 4, 8 and 16-s) individually revealed that high levels of accuracy developed relatively quickly under the shorter retention intervals, but increases in accuracy under the longer retention intervals sometimes were not observed until 100-150 sessions had passed, with some still increasing at Session 300. Analyses of errors suggested that retention intervals induced biases by shifting control from the sample stimulus to control by position, something that was predicted by observed response biases during initial training. These results suggest that although it may require a great deal of exposure to DMTS prior to obtaining asymptotic steady state, quantification of model parameters may help predict trends when extended exposure is not feasible.  相似文献   
920.
    
FRANS SVENSSON 《Theoria》2011,77(3):238-260
My main thesis in this article is that Descartes' ethics should be understood as involving a distinction between happiness and well‐being. The distinction I have in mind is never clearly stated or articulated by Descartes himself, but I argue that we nevertheless have good reason to embrace it as an important component in a charitable reconstruction of his ethical thought. In section I , I present Descartes' account of happiness and of how he thinks happiness can (and cannot) be acquired. Then, in section II , I introduce and develop the distinction between happiness and well‐being. I do this via a discussion of a difficult passage in one of Descartes' letters to Elisabeth, where he may seem first to grant and then immediately to reject the view that people's happiness can vary in degree depending on the possession of goods or perfections that are outside their power to control. I believe my proposed distinction can help us make good sense of this passage. In the last two sections (III and IV ), I then offer some further grounds or reasons for why the proposed distinction should be ascribed to Descartes.  相似文献   
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