The Differential Outcomes Effect

The Psychological Record - The differential outcomes effect refers specifically to the increase in speed of acquisition or terminal accuracy that occurs in discrimination training when each of two...     

On the fragility of medical virtue in a neoliberal context: the case of commercial conflicts of interest in reproductive medicine

Social, political, and economic environments play an active role in nurturing professional virtue. Yet, these environments can also lead to the erosion of virtue. As such, professional virtue is fragile and vulnerable to environmental shifts. While physicians are often considered to be among the most virtuous of professional groups, concern has also always existed about the impact of commercial arrangements on physicians’ willingness and capacity to enact their professional virtues. This article examines the ways in which commercial arrangements have been negotiated to secure medical virtue from real or perceived threats of erosion. In particular, we focus on the concern surrounding conflicts of interest arising from commercial arrangements that have developed as a result of neoliberal economic and social policies. The deregulation of medical markets and privatization of services have produced new commercial relationships that are often misunderstood by patients, publics, and physicians themselves. ‘Conflicts of interest’ policies have been introduced in an attempt to safeguard ethical conduct and medical practice. However, a number of virtue ethicists have critiqued these policies as inadequate for securing virtue. We examine the ways in which commercial arrangements have been seen to impact upon medical virtue, both historically and in the context of modern medicine (using the example of fertility services in Australia). We then describe and critique current efforts to restore clinical virtue through both conflict of interest policies and through virtue ethics. Finally, we suggest some possible ways of addressing the corrosive effects of neoliberalism on medical virtue.     

Choice between sequences of fixed-ratio schedules: effects of ratio values and probability of food delivery.

Pigeons were exposed to schedules of food delivery that consisted of two sequential fixed ratios. When alternative sequences provided two food deliveries per 50 responses, the schedule with the shorter initial fixed-ratio value was consistently preferred. Progressively reducing from 1.0 to .25 the probability of food delivery following completion of the second fixed ratio of the sequence with the shorter initial fixed ratio did not reduce preference for this sequence. Moreover, the sequence with the shorter initial fixed ratio also was preferred when the probability of food delivery following completion of the initial ratio in that sequence was progressively reduced from 1.0 to .5, although preference shifted to the alternative when the probability was reduced to 0. These findings suggest that the length of the initial fixed ratio was a primary determinant of choice. Subsequent manipulations demonstrated, however, that when the initial fixed ratios of the two alternatives were equal, changes in the ratio value and probability of food delivery following completion of the second fixed ratio lawfully affected choice.     

Choice between response units: The rate constancy model

In a conjoint schedule, reinforcement is available simultaneously on two or more schedules for the same response. The present experiments provided food for key pecking on both a random-interval and a differential-reinforcement-of-low-rate (DRL) schedule. Experiment 1 involved ordinary DRL schedules; Experiment 2 added an external stimulus to indicate when the required interresponse time had elapsed. In both experiments, the potential reinforcer frequency from each component was varied by means of a second-order fixed-ratio schedule, and the DRL time parameter was changed as well. Response rates were described by a model stating that time allocation to each component matches the relative frequency of reinforcement for that component. When spending time in a given component, the subject is assumed to respond at the rate characteristic of baseline performance. This model appeared preferable to the absolute-rate version of the matching law. The model was shown to be applicable to multiple-response concurrent schedules as well as to conjoint schedules, and it described some of the necessary conditions for response matching, undermatching, and bias. In addition, the pigeons did not optimize reinforcer frequency.     

A descriptive taxonomy of environmental operations and its implications for behavior analysis

Environmental operations may be classified according to whether they have evocative or function-altering effects. Evocative events, such as the presentation of unconditioned and conditioned stimuli, establishing operations, and discriminative stimuli, serve to increase, decrease, or maintain the momentary frequency of behavior. Function-altering operations, such as operant and respondent conditioning, the correlation of stimuli, and the presentation of certain verbal stimuli, serve to increase, decrease, or maintain the evocative and function-altering (e.g., reinforcing or punishing) functions of other events. This paper expands upon the functional taxonomy of environmental events described by Michael (1993a). The resulting classification scheme should permit behavior analysts to more easily respond to similarities and differences between functional environmental events. This paper discusses implications of the suggested taxonomy for how behavior analysts talk about motivational variables, discriminative stimuli, the operant unit of analysis, and the distinction between operant and respondent conditioning.     

Symptom reduction and termination: client change and therapist identified reasons for saying goodbye

Empirical efforts have focused on predicting whether or not clients prematurely terminate therapy, with nonattendance of last session equated to premature termination. However, this fails to explore the relationship between clients’ distress reduction and reasons for termination. With this study, we aimed to understand how clients’ distress change relates to premature termination and examine clients’ distress change in conjunction with therapists’ perceptions of termination reasons. We collected data from 797 clients who prematurely terminated or attended termination but completed therapy a minimum of three individual sessions provided by 38 therapists. Clients completed an assessment of psychological symptoms before each session. At the end of treatment, therapists identified the reasons they believed termination occurred for all clients in the sample. Results demonstrate that total sessions attended and missed predict premature termination, whereas distress change does not. Additionally, clients who were believed to accomplish goals do show greater change. However, therapists’ indicated that over half of clients did not reach goals at termination and they did not perceive nonattendance at last session to equate to drop out in all cases. Implications are discussed with respect to understanding why clients’ terminate, therapeutic goal conceptualization, and review of goals during termination in time-limited psychotherapy.