How do reinforcers affect choice? Preference pulses after responses and reinforcers

In concurrent schedules, reinforcers are often followed by a brief period of heightened preference for the just‐productive alternative. Such ‘preference pulses’ may reflect local effects of reinforcers on choice. However, similar pulses may occur after nonreinforced responses, suggesting that pulses after reinforcers are partly unrelated to reinforcer effects. McLean, Grace, Pitts, and Hughes (2014) recommended subtracting preference pulses after responses from preference pulses after reinforcers, to construct residual pulses that represent only reinforcer effects. Thus, a reanalysis of existing choice data is necessary to determine whether changes in choice after reinforcers in previous experiments were actually related to reinforcers. In the present paper, we reanalyzed data from choice experiments in which reinforcers served different functions. We compared local choice, mean visit length, and visit‐length distributions after reinforcers and after nonreinforced responses. Our reanalysis demonstrated the utility of McLean et al.'s preference‐pulse correction for determining the effects of reinforcers on choice. However, visit analyses revealed that residual pulses may not accurately represent reinforcer effects, and reinforcer effects were clearer in visit analyses than in local‐choice analyses. The best way to determine the effects of reinforcers on choice may be to conduct visit analyses in addition to local‐choice analyses.     

Higher order influences on evaluative priming: Processing styles moderate congruity effects

A growing body of research challenges the automaticity of evaluative priming (EP). The present research adds to this literature by suggesting that EP is sensitive to processing styles. We relied on previous research showing that EP is determined by the extent to which the prime and the target events on a given trial are processed as a unified compound. Here, we further hypothesised that processing styles encouraging the inclusion of the prime to the target episode support congruity effects, whereas processing styles that enhance the exclusion of the prime from the target episode interrupt (or reverse) these effects. In Experiment 1, a preceding similarity search task produced a congruity effect, whereas a dissimilarity search task eliminated and (non-significantly) reversed this effect. In Experiments 2 and 3, we replicated and extended these findings using a global/local processing manipulation. Overall, these findings confirm that EP is flexible, open to top-down influences and strategic regulation.     

Local dominance effects on self-evaluations and intrinsic motivation

Previous research indicates that local comparisons with one or a few people in the immediate environment have a stronger influence on self-evaluations than general comparisons with larger samples. Two studies examined whether this local dominance effect extends to intrinsic motivation. Study 1 suggests that local comparisons have a stronger effect on both self-evaluations and task enjoyment than general comparisons. Study 2 suggests that local comparisons have a stronger effect on intrinsic motivation than general comparisons and that local comparisons have a significant indirect effect on persistence via intrinsic motivation. Altogether, the present findings are among the first to demonstrate the contribution of local social comparisons to intrinsic motivation. We highlight the implications of these findings for social comparison theories.     

Reinforcing staying and switching while using a changeover delay

Performance on concurrent schedules can be decomposed to run lengths (the number of responses before switching alternatives), or visit durations (time at an alternative before switching alternatives), that are a function of the ratio of the rates of reinforcement for staying and switching. From this analysis, a model of concurrent performance was developed and examined in two experiments. The first exposed rats to variable-interval schedules for staying and for switching, which included a changeover delay for reinforcers following a switch. With the changeover delay, run lengths and visit durations were functions of the ratios of the rates of reinforcement for staying and for switching, as found by previous research not using a changeover delay. The second directly assessed the effect of a changeover delay on run lengths and visit durations. Each component of a multiple schedule consisted of equivalent stay and switch schedules but only one component included a changeover delay. Run lengths and visit durations were longer when a changeover delay was used. Because visit duration is the reciprocal of changeover rate, these results are consistent with the established finding that a changeover delay reduces the frequency of switching. Together these results support the local model of concurrent performance as an alternative to the generalized matching law as a model of concurrent performance. The local model may be preferred when accounting for more molecular aspects of concurrent performance.     

On the need for negative local item dependence

While negative local item dependence (LID) has been discussed in numerous articles, its occurrence and effects often go unrecognized. This is due in part to confusion over what unidimensional latent trait is being utilized in evaluating the LID of multidimensional testing data. This article addresses this confusion by using an appropriately chosen latent variable to condition on. It then provides a proof that negative LID must occur when unidimensional ability estimates (such as number right score) are obtained from data which follow a very general class of multidimensional item response theory models. The importance of specifying what unidimensional latent trait is used, and its effect on the sign of the LIDs are shown to have implications in regard to a variety of foundational theoretical arguments, to the simulation of LID data sets, and to the use of testlet scoring for removing LID.This paper is based in part on a chapter in the first author's doctoral dissertation, written at the University of Illinois at Urbana-Champaign under the supervision of William Stout. Part of this research has been presented at the annual meeting of the National Council on Measurement in Education, San Diego, California, April 14–16, 1998.The research of the first author was partially supported by a Harold Gulliksen Psychometric fellowship through Educational Testing Service and by a Research and Productive Scholarship award from the University of South Carolina.     

The logic of the stimulus

This paper examines the contribution of stimulus processing to animal logics. In the classic functionalist S-O-R view of learning (and cognition), stimuli provide the raw material to which the organism applies its cognitive processes–its logic, which may be taxon-specific. Stimuli may contribute to the logic of the organism's response, and may do so in taxon-specific ways. Firstly, any non-trivial stimulus has an internal organization that may constrain or bias the way that the organism addresses it; since stimuli can only be defined relative to the organism's perceptual apparatus, and this apparatus is taxon-specific, such constraints or biases will often be taxon-specific. Secondly, the representation of a stimulus that the perceptual system builds, and the analysis it makes of this representation, may provide a model for the synthesis and analysis done at a more cognitive level. Such a model is plausible for evolutionary reasons: perceptual analysis was probably perfected before cognitive analysis in the evolutionary history of the vertebrates. Like stimulus-driven analysis, such perceptually modelled cognition may be taxon-specific because of the taxon-specificity of the perceptual apparatus. However, it may also be the case that different taxa are able to free themselves from the stimulus logic, and therefore apply a more abstract logic, to different extents. This thesis is defended with reference to two examples of cases where animals' cognitive logic seems to be isomorphic with perceptual logic, specifically in the case of pigeons' attention to global and local information in visual stimuli, and dogs' failure to comprehend means-end relationships in string-pulling tasks.This contribution is part of the special issue “Animal Logics” (Watanabe and Huber 2006).     

Constant latent odds-ratios models and the mantel-haenszel null hypothesis

In the present paper, a new family of item response theory (IRT) models for dichotomous item scores is proposed. Two basic assumptions define the most general model of this family. The first assumption is local independence of the item scores given a unidimensional latent trait. The second assumption is that the odds-ratios for all item-pairs are constant functions of the latent trait. Since the latter assumption is characteristic of the whole family, the models are called constant latent odds-ratios (CLORs) models. One nonparametric special case and three parametric special cases of the general CLORs model are shown to be generalizations of the one-parameter logistic Rasch model. For all CLORs models, the total score (the unweighted sum of the item scores) is shown to be a sufficient statistic for the latent trait. In addition, conditions under the general CLORs model are studied for the investigation of differential item functioning (DIF) by means of the Mantel-Haenszel procedure. This research was supported by the Dutch Organization for Scientific Research (NWO), grant number 400-20-026.     

Matching visual stimuli on the basis of global and local features by chimpanzees (Pan troglodytes) and rhesus monkeys (Macaca mulatta)

This study was designed to examine whether chimpanzees and monkeys exhibit a global-to-local precedence in the processing of hierarchically organized compound stimuli, as has been reported for humans. Subjects were tested using a sequential matching-to-sample paradigm using stimuli that differed on the basis of their global configuration or local elements, or on both perceptual attributes. Although both species were able to discriminate stimuli on the basis of their global configuration or local elements, the chimpanzees exhibited a global-to-local processing strategy, whereas the rhesus monkeys exhibited a local-to-global processing strategy. The results suggest that perceptual and attentional mechanisms underlying information-processing strategies may account for differences in learning by primates. Accepted after revision: 11 September 2001 Electronic Publication     

Psychological individual differences as predictors of refugees’ local language proficiency

Learning the local language is important for the successful integration of immigrants. Previous research has identified a number of sociodemographic factors that are associated with the effectiveness of local language acquisition among immigrants, but little is known about the influence of psychological differences on immigrants’ local language acquisition. In the present research, individual differences in general mental ability (GMA), work search intention, and personality traits Conscientiousness and Openness were studied among recently arrived Syrian (n = 1054) and Eritrean (n = 500) refugees in the Netherlands. The results revealed that in addition to the effects of age of arrival, local length of stay, premigration educational attainment, and psychological distress, GMA and work search intention were positively associated with refugees’ local language proficiency. Additionally, work search intention was found to strengthen the effect of GMA on local language proficiency. No positive linear effects were observed for Conscientiousness and Openness. Some evidence was found for curvilinear relationships between psychological predictors and local language proficiency. Implications are discussed.     

Leibniz Filters Revisited

Leibniz filters play a prominent role in the theory of protoalgebraic logics. In [3] the problem of the definability of Leibniz filters is considered. Here we study the definability of Leibniz filters with parameters. The main result of the paper says that a protoalgebraic logic S has its strong version weakly algebraizable iff it has its Leibniz filters explicitly definable with parameters.