Health Promotion through Monetary Incentives: Evaluating the Impact of Different Reinforcement Schedules on Engagement Levels with a mHealth App

Background: Financial rewards can be employed in mHealth apps to effectively promote health behaviors. However, the optimal reinforcement schedule—with a high impact, but relatively low costs—remains unclear. Methods: We evaluated the impact of different reinforcement schedules on engagement levels with a mHealth app in a six-week, three-arm randomized intervention trial, while taking into account personality differences. Participants (i.e., university staff and students, N = 61) were awarded virtual points for performing health-related activities. Their performance was displayed via a dashboard, leaderboard, and newsfeed. Additionally, participants could win financial rewards. These rewards were distributed using a fixed schedule in the first study arm, and a variable schedule in the other arms. Furthermore, payouts were immediate in the first two arms, whereas payouts in the third arm were delayed. Results: All three reinforcement schedules had a similar impact on user engagement, although the variable schedule with immediate payouts was reported to have the lowest cost per participant. Additionally, the impact of financial rewards was affected by personal characteristics. Especially, individuals that were triggered by the rewards had a greater ability to defer gratification. Conclusion: When employing financial rewards in mHealth apps, variable reinforcement schedules with immediate payouts are preferred from the perspective of cost and impact.

A Biosemiotic Perspective on Reward-Based Animal Training Techniques

In this paper, I examine the way humans interact with domestic companion animals, with a focus on ‘positive reward-based training’ methods, particularly for dogs. From a biosemiotic perspective, I discuss the role of animal training in today’s society and examine what binary reward- based reinforcement schedules communicate, semiotically. I also examine the extent to which reward-based training methods promote better welfare, when compared to the more traditional methods which rely on aversive stimuli and punishment, if and when they are relied upon excessively. I conclude that when used as the primary means of communication, they have the potential to be detrimental to animal welfare, because the underlying social signal is control and resource dominance. As an alternative view to behaviourist-based learning theory and conditioning, I outline how enactivist theories of cognition support a semiotic approach to interspecific human-animal communication. I therefore propose a move toward a dynamic semiosis and mutual understanding based upon Peirce’s phenomenology, resulting in a more balanced merging of Umwelten. The aim is to create rich and more complex semiospheres around humans and domestic animals, which allow for individual agency and autonomy.

Intelligence Predicts Sensory Discrimination Ability but not Implicit Reward Learning

Previous research has made use of sensory discrimination tasks that incorporate differential reinforcement schedules as a method for measuring individual differences in implicit reward learning. One such task utilizing a differential reinforcement schedule was popularized by Pizzagalli et al. (2005) with the intent of behaviorally assessing anhedonia and reward sensitivity. Various studies have examined implicit reward learning in relation to clinical symptoms and personality traits, including anhedonia, depression, and Extraversion. Despite extensive use of these tasks, they have not been extensively examined in relation to intelligence. Other research suggests positive associations of intelligence with sensory discrimination ability. The present study utilized a probabilistic reward task incorporating differential reinforcement in a large community sample to determine the relations among IQ, sensory discrimination ability, and implicit reward learning. Participants (N = 298) completed a sensory discrimination task, as well as an IQ test. IQ was not associated with participants’ levels of implicit reward learning but was positively associated with sensory discrimination ability. These findings provide further understanding of the complex relations among implicit learning, sensory discrimination ability, and intelligence.

The Partial Reinforcement Extinction Effect: The Proportion of Trials Reinforced During Conditioning Predicts the Number of Trials to Extinction

Four experiments compared the extinction of responding to a continuously reinforced (CRf) conditioned stimulus (CS) consistently reinforced on every trial, with extinction of responding to a partially reinforced (PRf) CS that had been inconsistently reinforced. To equate the acquisition of responding between the two CSs, the average duration of the CRf CS was extended so that it scheduled the same overall rate of reinforcement per unit time as the PRf CS. Experiment 1 used a within-subjects design to compare the rates of extinction for a 10-s PRf CS reinforced on 33% of trials versus a 30-s CRf CS. Experiment 2 made the same comparison but using a between-subjects design. Experiment 3 compared extinction in a group trained with a 10-s PRf CS reinforced on 20% of trials and a group trained with a 50-s CRf CS. Experiment 4 compared the rates of extinction following two partial reinforcement schedules, a 10-s PRf CS reinforced on 33% of trial versus a 20-s CRf CS reinforced on 66% of trials. In each experiment, responding took longer to extinguish for the CS that scheduled a lower per-trial probability of reinforcement. Modelling of individual extinction curves using Weibull functions indicated that the latency to initiate extinction was directly related to the per-trial probability of reinforcement learned during acquisition. For example, compared to training with a CRf CS, rats reinforced on 33% of trials took approximately three times as many trials to initiate extinction, and rats reinforced on 20% of trials took five times as many trials to initiate extinction. These results provide support for trial-based accounts of extinction (e.g. Capaldi, 1967), whereby rats learn about the expected number of trials per reinforcer, and extinction depends on the number of expected reinforcers that have been omitted rather than on the number of extinction trials per se.

Dissociable dopaminergic and pavlovian influences in goal-trackers and sign-trackers on a model of compulsive checking in OCD

Rationale Checking is a functional behaviour that provides information to guide behaviour. However, in obsessive-compulsive disorder (OCD), checking may escalate to dysfunctional levels. The processes underpinning the transition from functional to dysfunctional checking are unclear but may be associated with individual differences that support the development of maladaptive behaviour. We examined one such predisposition, sign-tracking to a pavlovian conditioned stimulus, which we previously found associated with dysfunctional checking. How sign-tracking interacts with another treatment with emerging translational validity for OCD-like checking, chronic administration of the dopamine D2 receptor agonist quinpirole, is unknown. Objectives We tested how functional and dysfunctional checking in the rat observing response task (ORT) was affected by chronic quinpirole administration in non-autoshaped controls and autoshaped animals classified as sign-trackers or goal-trackers. Methods Sign-trackers or goal-trackers were trained on the ORT before the effects of chronic quinpirole administration on checking were assessed. Subsequently, the effects on checking of different behavioural challenges, including reward omission and the use of unpredictable reinforcement schedules, were tested. Results Prior autoshaping increased checking. Sign-trackers and goal-trackers responded differently to quinpirole sensitization, reward omission and reinforcement uncertainty. Sign-trackers showed greater elevations in dysfunctional checking, particularly during uncertainty. By contrast, goal-trackers predominantly increased functional checking responses, possibly in response to reduced discrimination accuracy in the absence of cues signalling which lever was currently active. Conclusions The results are discussed in terms of how pavlovian associations influence behaviour that becomes compulsive in OCD and how this may be dependent on striatal dopamine D2 receptors.

Desperately Seeking Support: Negative Reinforcement Schedules in the Formation of Adult Attachment Associations

Much is unknown about adult attachment style formation. We investigate whether negative reinforcement schedules promote hallmark features of secure and anxious attachment styles in a shock-threat support-seeking paradigm. Participants ostensibly asked for help from another participant seated in another room. Each time a shock threat signal appeared they were to press a button to indicate their need for help. The supporter could then stop the imminent shock. The reliability of the supporters was varied such that some supporters were consistent (continuous reinforcement) whereas others were inconsistent (variable-ratio reinforcement). Results indicated that inconsistently responsive others, reinforcing on a variable-ratio schedule, led to heightened approach related attentional biases toward the supporter, measured by event related potentials, increased positive attachment associations with the supporter, implicitly measured via a lexical decision task, and more negative explicit evaluations of the supporter.