Token Economies: Using Basic Experimental Research to Guide Practical Applications

This paper highlights the applicability of patterns seen within basic experimental research in relation to contemporary application of token economies. Token economies are one of the most widely used interventions to promote behavior change, and this procedure has evolved to be effective across many settings, behaviors, and individuals. Due to this widespread use, casual implementation of the token economy might result in inconsistencies in responding and therefore an overall skepticism in the procedure itself. We present multiple barriers that encumber practical application of token economies, including insufficient conditioning and pairing of tokens, determining quality of backup reinforcers, unforeseen effects of motivating operations, teaching the token exchange, effects of higher-order reinforcement schedules, ratio strain, and use of response cost procedures. To assist practitioners in implementing more effective treatments, for each barrier we revisit the often overlooked basic research involving features of conditioned reinforcement and reinforcement schedules. It is important to translate the often complex implications of basic research so that practitioners can use this information to improve their own practice as well as their confidence in disseminating use of this evidence-based treatment. To further guide practitioners in using this knowledge in everyday settings, we also provide recommendations specific to each barrier as well as relevant applied research and practical examples.     

Intuitive optics: what great apes infer from mirrors and shadows

There is ongoing debate about the extent to which nonhuman animals, like humans, can go beyond first-order perceptual information to abstract structural information from their environment. To provide more empirical evidence regarding this question, we examined what type of information great apes (chimpanzees, bonobos, and orangutans) gain from optical effects such as shadows and mirror images. In an initial experiment, we investigated whether apes would use mirror images and shadows to locate hidden food. We found that all examined ape species used these cues to find the food. Follow-up experiments showed that apes neither confused these optical effects with the food rewards nor did they merely associate cues with food. First, naïve chimpanzees used the shadow of the hidden food to locate it but they did not learn within the same number of trials to use a perceptually similar rubber patch as indicator of the hidden food reward. Second, apes made use of the mirror images to estimate the distance of the hidden food from their own body. Depending on the distance, apes either pointed into the direction of the food or tried to access the hidden food directly. Third, apes showed some sensitivity to the geometrical relation between mirror orientation and mirrored objects when searching hidden food. Fourth, apes tended to interpret mirror images and pictures of these mirror images differently depending on their prior knowledge. Together, these findings suggest that apes are sensitive to the optical relation between mirror images and shadows and their physical referents.     

Bayes factors for the linear ballistic accumulator model of decision-making

Evidence accumulation models of decision-making have led to advances in several different areas of psychology. These models provide a way to integrate response time and accuracy data, and to describe performance in terms of latent cognitive processes. Testing important psychological hypotheses using cognitive models requires a method to make inferences about different versions of the models which assume different parameters to cause observed effects. The task of model-based inference using noisy data is difficult, and has proven especially problematic with current model selection methods based on parameter estimation. We provide a method for computing Bayes factors through Monte-Carlo integration for the linear ballistic accumulator (LBA; Brown and Heathcote, 2008), a widely used evidence accumulation model. Bayes factors are used frequently for inference with simpler statistical models, and they do not require parameter estimation. In order to overcome the computational burden of estimating Bayes factors via brute force integration, we exploit general purpose graphical processing units; we provide free code for this. This approach allows estimation of Bayes factors via Monte-Carlo integration within a practical time frame. We demonstrate the method using both simulated and real data. We investigate the stability of the Monte-Carlo approximation, and the LBA’s inferential properties, in simulation studies.     

Differing views: Can chimpanzees do Level 2 perspective-taking?

Although chimpanzees understand what others may see, it is unclear whether they understand how others see things (Level 2 perspective-taking). We investigated whether chimpanzees can predict the behavior of a conspecific which is holding a mistaken perspective that differs from their own. The subject competed with a conspecific over two food sticks. While the subject could see that both were the same size, to the competitor one appeared bigger than the other. In a previously established game, the competitor chose one stick in private first and the subject chose thereafter, without knowing which of the sticks was gone. Chimpanzees and 6-year-old children chose the ‘riskier’ stick (that looked bigger to the competitor) significantly less in the game than in a nonsocial control. Children chose randomly in the control, thus showing Level 2 perspective-taking skills; in contrast, chimpanzees had a preference for the ‘riskier’ stick here, rendering it possible that they attributed their own preference to the competitor to predict her choice. We thus run a follow-up in which chimpanzees did not have a preference in the control. Now, they also chose randomly in the game. We conclude that chimpanzees solved the task by attributing their own preference to the other, while children truly understood the other’s mistaken perspective.     

Relationship between nicotinic receptors and cognitive function in early Alzheimer's disease: a 2-[18F]fluoro-A-85380 PET study

Neuronal nicotinic acetylcholine receptors (nAChRs) are critical for higher order cognitive processes. Post-mortem studies suggest reductions in nAChRs (particularly the alpha(4)beta(2) subtype) with ageing and in Alzheimer's disease (AD). This study aimed to; (1) quantify nAChR distribution in vivo with 2-[18F]fluoro-A-85380 (2-FA) in 15 early AD patients compared to 14 age-matched, healthy controls (HC) and (2) correlate nAChR distribution with cognitive performance in both groups. All participants were non-smokers and underwent cognitive testing along with a dynamic PET scan after injection of 200 MBq of 2-FA. Brain regional 2-FA binding was assessed through a simplified estimation of Distribution Volume (DV(S)). The AD group differed significantly from HC on all cognitive measures employed, with impairments on measures of attention, working memory, language, executive function, visuospatial ability, verbal learning and verbal memory (p<.05). Contrary to post-mortem data this study found no evidence of in vivo nAChR loss in early AD despite significant cognitive impairment. Furthermore, no correlation between nAChR and cognitive performance was found for either group. The findings of the current study suggest preservation of nAChRs early in AD supporting previous studies. It is possible that while the clinical 2-FA PET method described here may be insensitive in detecting changes in early AD, such changes may be detected in more advanced stages of the illness.     

Tracking and inferring spatial rotation by children and great apes

Finding hidden objects in space is a fundamental ability that has received considerable research attention from both a developmental and a comparative perspective. Tracking the rotational displacements of containers and hidden objects is a particularly challenging task. This study investigated the ability of 3-, 5-, 7-, and 9-year-old children and great apes (chimpanzees, bonobos, gorillas, and orangutans) to (a) visually track rotational displacements of a baited container on a platform and (b) infer its displacements by using the changes of position or orientation of 3 landmarks: an object on a container, the color of the containers, and the color of the platform on which the containers rested. Great apes and 5-year-old and older children successfully tracked visible rotations, but only children were able to infer the location of a correct cup (with the help of landmarks) after invisible rotations. The ability to use landmarks changed with age so that younger children solved this task only with the most explicit marker on the baited container, whereas older children, particularly 9-year-olds, were able to use landmark orientation to infer correct locations.     

How the great apes (Pan troglodytes, Pongo pygmaeus, Pan paniscus, Gorilla gorilla) perform on the reversed reward contingency task II: transfer to new quantities, long-term retention, and the impact of quantity ratios

We tested 6 chimpanzees (Pan troglodytes), 3 orangutans (Pongo pygmaeus), 4 bonobos (Pan paniscus), and 2 gorillas (Gorilla gorilla) in the reversed reward contingency task. Individuals were presented with pairs of quantities ranging between 0 and 6 food items. Prior to testing, some experienced apes had solved this task using 2 quantities while others were totally na?ve. Experienced apes transferred their ability to multiple-novel pairs after 6 to 19 months had elapsed since their initial testing. Two out of 6 na?ve apes (1 chimpanzee, 1 bonobo) solved the task--a proportion comparable to that of a previous study using 2 pairs of quantities. Their acquisition speed was also comparable to the successful subjects from that study. The ratio between quantities explained a large portion of the variance but affected na?ve and experienced individuals differently. For smaller ratios, na?ve individuals were well below 50% correct and experienced ones were well above 50%, yet both groups tended to converge toward 50% for larger ratios. Thus, some apes require no procedural modifications to overcome their strong bias for selecting the larger of 2 quantities.     

Effects of message, source, and context on evaluations of employee voice behavior

The article contained a production-related error. In Table 5, the four values in the rows for Study 1 Prosocial motives and Study 1 Constructive voice should have been shifted one column to the right, to the Direct and Total Performance evaluations columns. All versions of this article have been corrected.] Although employee voice behavior is expected to have important organizational benefits, research indicates that employees voicing their recommendations for organizational change may be evaluated either positively or negatively by observers. A review of the literature suggests that the perceived efficacy of voice behaviors may be a function of characteristics associated with the (a) source, (b) message, and (c) context of the voice event. In this study, we manipulated variables from each of these categories based on a model designed to predict when voice will positively or negatively impact raters' evaluations of an employee's performance. To test our model, we conducted 3 laboratory studies in which we manipulated 2 source factors (voicer expertise and trustworthiness), 2 message factors (recommending a solution and positively vs. negatively framing the message), and 2 context factors (timing of the voice event and organizational norms for speaking up vs. keeping quiet). We also examined the mediating effects of liking, prosocial motives, and perceptions that the voice behavior was constructive on the relationships between the source, message, and context factors and performance evaluations. Generally speaking, we found that at least one of the variables from each category had an effect on performance evaluations for the voicer and that most of these effects were indirect, operating through one or more of the mediators. Implications for theory and future research are discussed.     

The Phenomenology of Posttraumatic Distress in Older Adult Holocaust Survivors

This paper focuses on the effects of the Holocaust on its survivors more than 55 years after the end of World War II. The emphasis is on survivors who were either adults during the Holocaust and who are now over the age of 70, or survivors who were children during the Holocaust and whose age is now between 56 and 70. The central question was: What kinds of posttraumatic phenomena are seen in older adult survivors? After an overview of the field, the situation of survivors in Israel is presented in 2 ways. Results of a survey of survivors who were referred to Amcha, the National Israeli Center for Psychosocial Support of Survivors of the Holocaust, is provided to give some insight in a clinical population. In addition, 2 case histories of survivors are presented to give a more in-depth perspective. The gap between the data from the questionnaires and the clinical material has relevance for the way in which we conceptualize the late consequences of massive trauma.