产品类型对购物冲量效应的调节作用分析

基于享乐品-实用品有关研究及购物冲量效应, 考察产品类型对购物冲量效应的调节作用及其内在机制。实验一通过现场研究验证购买实用品提高后续购买概率, 购买享乐品降低其概率; 实验二为实验室实验, 再次验证该调节作用, 并验证内在原因：购买享乐品更可能激发内疚感、花钱的痛苦甚至负面自我形象和高层次目标, 导致理由性思维占主导, 前次购买引发的应用思维定式受到削弱。相比于实用品, 购买享乐品引发购物冲量效应的可能性更低。     

Using paired-choice assessment to identify variables maintaining sleep problems in a child with severe disabilities

In this study, we used a paired-choice assessment protocol to identify the relative reinforcing value of stimuli and activities for a child with severe disabilities when she failed to settle to sleep at night. The results of this assessment indicated that the child preferred the mother's attention relative to other activities presented. Assessment results were incorporated into an intervention, that produced a reduction in sleep disturbance that was maintained at a 12-month follow up.     

Effects of experience on preference between forced and free choice

Preference between forced choice and free choice in concurrent-chain schedules of reinforcement was investigated in pigeons after exposure to particular combinations of terminal links. In Experiment 1, in which terminal links always ended with reinforcers, one of three pairs of terminal links was arranged as preexposure: (a) both terminal links had only one key (forced choice), (b) both terminal links had two keys (free choice), or (c) a combination of forced and free choice was arranged across sessions. In test sessions following the preexposure, pigeons' preferences rapidly shifted to the terminal links with which they had no recent experience. In Experiment 2, the same procedure was repeated except that each terminal link ended intermittently with reinforcers with a probability of .5 and there was no terminal-link arrangement with a combination of free and forced choice. Pigeons showed the same preference changes as in Experiment 1, but the preference changes did not appear immediately at the beginning of test sessions. These data suggest that recent previous experience was a more important determinant of preference than the difference between forced-choice and free-choice terminal links.     

Independence of terminal-link entry rate and immediacy in concurrent chains

In Phase 1, 4 pigeons were trained on a three-component multiple concurrent-chains procedure in which components differed only in terms of relative terminal-link entry rate. The terminal links were variable-interval schedules and were varied across four conditions to produce immediacy ratios of 4:1, 1:4, 2:1, and 1:2. Relative terminal-link entry rate and relative immediacy had additive and independent effects on initial-link response allocation, and the data were well-described by a generalized-matching model. Regression analyses showed that allowing sensitivity to immediacy to vary across components produced only trivial increases in variance accounted for. Phase 2 used a three-component concurrent-schedules procedure in which the schedules were the same as the initial links of Phase 1. Across two conditions, the relative reinforcer magnitude was varied. Sensitivity to relative reinforcer rate was independent of relative magnitude, confirming results of prior studies. Sensitivity to relative reinforcer rate in Phase 2 did not vary systematically across subjects compared to sensitivity to relative entry rate in Phase 1, and regression analyses confirmed again that only small increases in variance accounted for were obtained when sensitivities were estimated independently compared with a single estimate for both phases. Overall, the data suggest that conditioned and primary reinforcers have functionally equivalent effects on choice and support the independence of relative terminal-link entry rate and immediacy as determiners of response allocation. These results are consistent with current models for concurrent chains, including Grace's (1994) contextual choice model and Mazur's (2001) hyperbolic value-added model.     

The repeated insertion model for rankings: Missing link between two subset choice models

Several probabilistic models for subset choice have been proposed in the literature, for example, to explain approval voting data. We show that Marley et al.'s latent scale model is subsumed by Falmagne and Regenwetter's size-independent model, in the sense that every choice probability distribution generated by the former can also be explained by the latter. Our proof relies on the construction of a probabilistic ranking model which we label the repeated insertion model. This model is a special case of Marden's orthogonal contrast model class and, in turn, includes the classical Mallows -model as a special case. We explore its basic properties as well as its relationship to Fligner and Verducci's multistage ranking model.The authors are grateful to the National Science Foundation for grants SES98-18756 to Regenwetter and Peke, and SBR97-30076 to Regenwetter. This collaborative research was carried out in the context of the conference Random Utility 2000 held at Duke University and sponsored by NSF, the Fuqua School of Business and the Center for International Business Education and Research. We thank the editor and four referees for helpful suggestions and we are grateful to Prof. J. I. Marden for providing useful information on contrast models. We thank Moon-Ho Ho for programming and running the data analyses.     

Modification of slot-machine preferences through the use of a conditional discrimination paradigm

The present experiment investigated the impact of contextually trained discriminations on gambling behavior. Nine recreational slot-machine players were initially exposed to concurrently available computerized slot machines that were each programmed on random-ratio schedules of reinforcement and differed only in color. All participants distributed responding equally across the two slot machines. A conditional discrimination procedure was then used to teach the contextual cues representing the arbitrary relations of "greater than" and "less than." Following contextual cue training, participants were reexposed to the concurrent slot-machine task. After training of the contextual cues, a higher proportion of responses were made to the slot machine that shared formal properties (i.e., color) with the contextual cue representing "greater than."     

Contextual control of delay discounting by pathological gamblers

The present study demonstrated the relative impact of gambling and nongambling contexts on the degree of delay discounting by pathological gamblers. We used a delay-discounting task with 20 pathological gamblers in and out of the natural context in which they regularly gambled. For 16 of the 20 participants, it appeared that the difference of context altered the subjective value of delayed rewards, thereby producing relative changes in delay-discounting rates that were generally consistent with a hyperbolic model of intertemporal choice. The current data suggest that empirically derived k values from delay-discounting tasks are context sensitive and are not constant across various settings for the individual. Implications for future transitional research on addictive disorders generally, and gambling specifically, are discussed.     

Influence of temporal context on value in the multiple-chains and successive-encounters procedures

This set of studies explored the influence of temporal context across multiple-chain and multiple-successive-encounters procedures. Following training with different temporal contexts, the value of stimuli sharing similar reinforcement schedules was assessed by presenting these stimuli in concurrent probes. The results for the multiple-chain schedule indicate that temporal context does impact the value of a conditioned reinforcer consistent with delay-reduction theory, such that a stimulus signaling a greater reduction in delay until reinforcement has greater value. Further, nonreinforced stimuli that are concurrently presented with the preferred terminal link also have greater value, consistent with value transfer. The effects of context on value for conditions with the multiple-successive-encounters procedure, however, appear to depend on whether the search schedule or alternate handling schedule was manipulated, as well as on whether the tested stimuli were the rich or lean schedules in their components. Overall, the results help delineate the conditions under which temporal context affects conditioned-reinforcement value (acting as a learning variable) and the conditions under which it does not (acting as a performance variable), an issue of relevance to theories of choice.     

Matching and conditioned reinforcement rate

Attempts to examine the effects of variations in relative conditioned reinforcement rate on choice have been confounded by changes in rates of primary reinforcement or changes in the value of the conditioned reinforcer. To avoid these problems, this experiment used concurrent observing responses to examine sensitivity of choice to relative conditioned reinforcement rate. In the absence of observing responses, unsignaled periods of food delivery on a variable-interval 90-s schedule alternated with extinction on a center key (i.e., a mixed schedule was in effect). Two concurrently available observing responses produced 15-s access to a stimulus differentially associated with the schedule of food delivery (S+). The relative rate of S+ deliveries arranged by independent variable-interval schedules for the two observing responses varied across conditions. The relation between the ratio of observing responses and the ratio of S+ deliveries was well described by the generalized matching law, despite the absence of changes in the rate of food delivery. In addition, the value of the S+ deliveries likely remained constant across conditions because the ratio of S+ to mixed schedule food deliveries remained constant. Assuming that S+ deliveries serve as conditioned reinforcers, these findings are consistent with the functional similarity between primary and conditioned reinforcers suggested by general choice theories based on the concatenated matching law (e.g., contextual choice and hyperbolic value-added models). These findings are inconsistent with delay reduction theory, which has no terms for the effects of rate of conditioned reinforcement in the absence of changes in rate of primary reinforcement.