A test of the reward-value hypothesis

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.     

A negative test of the drive-reduction hypothesis

A major deduction of the drive-reduction hypothesis of reinforcement was tested. A light which follows the termination of a shock coincides with a condition of drive or need reduction. If drive reduction is a sufficient condition for reinforcement, then the light should become a secondary reinforcing agent by virtue of its association with the drive-reduction event. If it becomes a secondary reinforcing agent, it should be able to reinforce an instrumental act.

This sequence of deductions was tested by placing rats in a stock, giving them a brief shock upon the termination of which a light was flashed for one second. After sixty such pairings, subjects were then placed in a Skinner box under operant test conditions; when they pressed the bar a light flashed on.

Animals subjected to this training programme were compared for rate of bar pressing with animals subjected to a variety of control conditions. No significant differences were found among the groups, and it was concluded that in so far as the deductions from drive-reduction theory were correct, the theory was not substantiated. The paper concludes with a discussion of various problems which might limit the interpretation of the experimental results.     

A strong test of the dual-mode hypothesis

One account of facial cognition, the dual-mode hypothesis, maintains that there are two sources of information in a human face, featural and configural, and that these sources are processed simultaneously and independently of one another. According to the hypothesis, the processing and identification of upright faces relies primarily on configural information, and this information is disrupted to such an extent upon inversion as to result in a reliance on featural information for identifying inverted faces (e.g., Searcy & Bartlett, 1996). When considered in terms of the general characteristics of human information processing, the foundational assumptions of the dual-mode hypothesis are as follows: Facial information processing is accomplished by a parallel self-terminating architecture with unlimited capacity to supercapacity and a preservation of independence between the rates of processing of featural and configural information. Although a number of studies have provided evidence consistent with the dual-mode hypothesis, until now there have been no direct tests of the foundational assumptions of the hypothesis. The present study provides that direct test, providing strong support for three of the assumptions (parallel self-terminating processing with unlimited capacity to supercapacity) while contradicting a fourth (independence in rates).     

Cities and the real world

It is generally recognized that modern cities pose many problems for their inhabitants and contribute to environmental damage. However, neither planners nor scientists give adequate consideration to cities’ place in the evolutionary process and the planet's ecological system. By recognizing these connections and natural laws, planning would become more realistic, and meaningful progress could be made in solving serious social and environmental problems. Some basic problems influencing urban form are discussed, and a schematic example of how we might approach the planning of urban settlements is presented.     

Bridging attentional control and reinvestment: A test of the interactionist hypothesis in an E-sport context

Attentional control and reinvestment are two competing mechanisms explaining why anxiety-provoking situations may undermine performance. To date, both perspectives have received empirical support, but neither of them perfectly explain how anxiety affects performance. In the present study, we examined a novel, interactionist hypothesis, that worry during task performance (i.e., a product of low attentional control) undermines performance to a greater extent when reinvestment (i.e., attempts to consciously control actions) is high compared to low, in an E-sport context. In a test of 84 experienced players in the Brawlhalla E-sport game, neither worry during the games nor reinvestment propensity on their own predicted ranked match performance, but the interaction between the two did. Specifically, players who were more worried during the ranked games (i.e., lower attentional control) tended to lose more games, of which the effect was evident only when movement-specific reinvestment was high, not low. However, decision-specific reinvestment did not moderate the effect of low attentional control on performance, nor predict performance on its own. Unlike movement-specific reinvestment, decision-specific reinvestment does not appear detrimental to E-sport performance. Overall, the findings provide the first evidence for the interactionist hypothesis of attentional control and reinvestment (especially movement-specific propensity), of which the interaction effect may be underpinned by availability of additional cognitive resources that assure adaptive task processing.     

A laboratory test of the constant risk hypothesis

It has been repeatedly suggested that subjects aim at maintaining a constant error probability in many variants of self-paced performance and that they adjust their behaviour so as to keep their risks relatively constant. This constant risk hypothesis is investigated in a simple computer-controlled addition task it which subjects manipulated exercise difficulty as a function of their own calculation proficiency and the allotted solution time. Error probability proved to be unrelated to level of skill and to amount of allotted computation time, but to depend onuncertainty with respect to exercise difficulty.     

A demonstration of a token economy for the real world

Token economies are rarely used in real-world psychiatric settings because of barriers to their implementation, such an institutional constraints and insufficient collegial support. The line-level treatment team at Elgin Mental Health Center was able to overcome these contraints and develop a user-friendly token economy. This article describes Elgin's simple yet effective token economy and the process used to develop it.     

A demonstration of a token economy for the real world

Token economies are rarely used in real-world psychiatric settings because of barriers to their implementation, such an institutional constraints and insufficient collegial support. The line-level treatment team at Elgin Mental Health Center was able to overcome these contraints and develop a user-friendly token economy. This article describes Elgin's simple yet effective token economy and the process used to develop it.     

Braking reaching movements: a test of the constant tau-dot strategy under different viewing conditions

Following F. Zaal and R. J. Bootsma (1995), the authors studied whether the decelerative phase of a reaching movement could be modeled as a constant tau-dot strategy resulting in a soft collision with the object. Specifically, they investigated whether that strategy is sustained over different viewing conditions. Participants (N = 11) were required to reach for 15- and 50-mm objects at 2 different distances under 3 conditions in which visual availability of the immediate environment and of the reaching hand were varied. Tau-dot estimates and goodness-of-fit were highly similar across the 3 conditions. Only within-participant variability of tau-dot estimates was increased when environmental cues were removed. That finding suggests that the motor system uses a tau-dot strategy involving the intermodal (i.e., visual, proprioceptive, or both) specification of information to regulate the decelerative phase of reaching under restricted viewing conditions. The authors provide recommendations for improving the derivation of tau;(x) estimates and stress the need for further research on how time-to-contact information is used in the regulation of the dynamics of actions such as reaching.     

Confidence in expectations: A test of the triangle hypothesis

Kelley and Stahelski's (1970) triangle hypothesis states that competitors hold homogeneous views of others by assuming that most others are competitive, whereas cooperators or pro-social people hold more heterogeneous views by assuming that others are either cooperative or competitive. To evaluate the triangle hypothesis, this study examines differences between pro-socials, individualists, and competitors not only in their expectations about others' choice behaviour, but also in the confidence with which such expectations are held. It was found that pro-social subjects expected more cooperation than individualists and competitors. More importantly, as predicted on the basis of the triangle hypothesis, pro-socials were less confident about their expectations than competitors, with individualists holding intermediate levels of confidence.     

Developmental psychology in the real world: A paradigm of parent education

Twenty years ago, William Kessen, Greta Fein and I developed and tested a model of parent education, a model which involved variation in curricular content, didactic approaches, and child outcomes–experimentally contrasted. Our experience yielded some valuable lessons about the extent to which researchers can influence parents' behaviour, and parents their children's development. In the present article I suggest that these lessons might be useful for researchers now as they were for us then. I present some observations about the research that developmental psychologists have done in the intervening two decades and suggest that we could learn much by using such a model of parent education to answer questions about the effets of parents' behaviour on children's development. Carefully done, parent education studies can yield valuable information about many of the questions raised in recent correlational research. Parent training research can suggest hypotheses that can be tested with data collected non-interventively and analysed in causal model analyses–and vice versa. What is more, because one reason for studying parent effects is so that we can offer guidance to parents about rearing their children, this design has a particular advantage; it is both the medium and the message.