Optimal learning strategies and their spontaneous use: The importance of task-appropriate processing

College students were given three verbal learning tasks to perform, with some subjects instructed to use a particular verbal or imaginal encoding strategy for all three tasks and other subjects not instructed to use any particular strategy. It was found that the relative effectiveness of the assigned encoding strategies varied as a function of the learning task. In addition, “uninstructed” subjects, for the most part, spontaneously employed strategies that produced recall comparable to that observed for subjects assigned the most effective strategy for a particular learning task. In Experiment 2, subjects were instructed to perform a different encoding strategy for each learning task. Subjects who were assigned the strategies in a “task-appropriate” fashion recalled more, in general, than subjects who were assigned the same strategies paired with the learning tasks in a haphazard fashion. Subjects not instructed to use a particular strategy again demonstrated relatively high recall and were found to vary processing across learning tasks. It was concluded that optimal learning for a range of tasks can require deployment of several semantic/elaborative strategies in a task-appropriate fashion. Furthermore, mature learners seem to spontaneously utilize semantic and imaginal strategies and do so task appropriately.     

Autonomy and coercion in disease prevention and health promotion

Most of the attention regarding the balance between autonomy and paternalism has been focused on the therapeutic relation. Much less attention has been devoted to the problem of autonomy in the application of medical knowledge for preventive purposes. Here, because the good to be achieved is social as well as individual, an unavoidable dilemma ensues. Effective preventive measures of benefit to all must necessarily limit autonomy and involve some coercion. I argue that there are principles which can be established to guide society in a moral use of coercion. The question of employing medical knowledge is not, as it is in therapeutic medicine, to preserve or enhance autonomy. Rather its aim is to enhance voluntary co-operation. Principles for moral use of coercion must thereby be derived from health as a moral value.     

Simultaneously contrasting anchors

Subjects were required to judge a series of weights in the presence of two opposing anchor weights, one heavier and one lighter than the series members. It was predicted that the anchors would enhance each other’s effectiveness (contrast). The findings are similar to that found for the single-anchor experiment, with the exception that, and contrary to prediction, the heavier-weight anchor reduced the effectiveness of the lighter-weight anchor. The opposite effect was not true. It is suggested that a pair of opposing anchors could be identified that would completely cancel each other’s effectiveness.     

Ethical dilemmas in the treatment of adolescent gang members

Therapists treating adolescent gang members face unique ethical dilemmas. These dilemmas arise from clinical issues that inevitably emerge in the treatment of this population. Clinical issues related to the adolescent gang member having great difficulty trusting, having experienced and observed much violence, and usually having participated in criminal activities are central to the treatment process. In this article I discuss the ethical problems that subsequently emerge: maintaining confidentiality, discharging one's duty to warn or protect, and imposing one's personal values. Suggestions for future research are offered.     

Secondary reinforcement and number of primary reinforcements

Pigeons' pecks on either of two concurrently available response keys produced secondary reinforcers according to independent one-minute variable-interval schedules. Different secondary reinforcers, in the presence of which the rates of primary reinforcement were equal, were associated with each key. The rate of pecking maintained by each secondary reinforcer varied directly, but nonproportionally, with the number of primary reinforcements given in the presence of the secondary reinforcer.     

The sunk‐time effect: An exploration

We explored the potential for a sunk‐cost effect in the realm of time. Questionnaire studies (Experiments 1–4) obtained a sunk‐time effect that was robust to manipulations of prospective value, individual versus group consequences, and the effort or enjoyment inherent in the time. Behavioral experiments (Experiments 5–7) also suggested a sunk‐time effect and found support for a personal responsibility by sunk‐cost interaction on choice behavior. We discuss theoretical implications and a potential connection to animal sunk‐cost phenomena. Copyright © 2008 John Wiley & Sons, Ltd.     

An attractor network in the hippocampus: theory and neurophysiology

A quantitative computational theory of the operation of the CA3 system as an attractor or autoassociation network is described. Based on the proposal that CA3-CA3 autoassociative networks are important for episodic or event memory in which space is a component (place in rodents and spatial view in primates), it has been shown behaviorally that the CA3 supports spatial rapid one-trial learning and learning of arbitrary associations and pattern completion where space is a component. Consistent with the theory, single neurons in the primate CA3 respond to combinations of spatial view and object, and spatial view and reward. Furthermore, single CA3 neurons reflect the recall of a place from an object in a one-trial object-place event memory task. CA3 neurons also reflect in their firing a memory of spatial view that is retained and updated by idiothetic information to implement path integration when the spatial view is obscured. Based on the computational proposal that the dentate gyrus produces sparse representations by competitive learning and via the mossy fiber pathway forces new representations on the CA3 during learning (encoding), it has been shown behaviorally that the dentate gyrus supports spatial pattern separation during learning, and that the mossy fiber system to CA3 connections are involved in learning but not in recall. The perforant path input to CA3 is quantitatively appropriate to provide the cue for recall in CA3. The concept that the CA1 recodes information from CA3 and sets up associatively learned back-projections to neocortex to allow subsequent retrieval of information to neocortex provides a quantitative account of the large number of hippocampo-neocortical back-projections.