Increasing motivation in effort-based decision-making tasks: effects of salience and reward expectancy manipulations

ABSTRACT

Background

A significant proportion of patients with affective and psychotic disorders show a marked reduction in goal-directed behaviour, which is also reflected in the behavioural outcomes of effort-based decision-making paradigms. The factors underlying this reduction are not yet fully understood. Reward salience and reward expectancy have been discussed as factors that potentially influence approach behaviour. The aim of this study was thus to test their effects on behaviour in an effort-based decision-making paradigm.

Methods

In two studies with community samples we applied a modified version of the Balloon Task. In study 1, we manipulated reward salience in a within-subject design (N = 32) by highlighting the monetary rewards. In study 2, we manipulated reward expectancy in a between-subject design (N = 72) by adding five practice trials with either positive or negative feedback prior to the task.

Results

The salience of rewards manipulation significantly increased effort expenditure and the allocation of effort to the level of rewards whereas the reward expectancy manipulation did not.

Conclusions

The finding that increasing the salience of rewards increases motivated behaviour in an effort-based decision-making paradigm offers promising possibilities for intervention in disorders characterised by motivational deficits, such asaffective and psychotic disorders.

KEYWORDS:

• Motivation
• negative symptoms
• salience
• reward expectancy
• intervention

Acknowledgements

We thank all participants for participating in our research.

Disclosure statement

None of the authors have a conflict of interest including any financial, personal or other relationships with other people or organisations within three years of beginning the work submitted that could inappropriately influence, or be perceived to influence, their work.

Contributors

Katharina E. Renz and Tania M. Lincoln designed the study and wrote the protocol. Katharina E. Renz managed the literature searches. Katharina E. Renz and Matthias Pillny managed the statistical analyses. Katharina E. Renz wrote the first draft of the manuscript and Tania M. Lincoln revised the manuscript. All three authors contributed to and have approved the final manuscript.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Notes on contributors

Katharina E. Renz

Katharina E. Renz is a clinical psychologist and studied at the Universität Hamburg, Germany, she is currently a PhD student at the department for Clinical Psychology and Psychotherapy at the Universität Hamburg and researches on negative symptoms in psychotic disorders.

Matthias Pillny

Matthias Pillny studied clinical psychology at the Ruhr–Universität Bochum, Germany. He currently works as a post–doctoral researcher at the department for Clinical Psychology and Psychotherapy at the Universität Hamburg, Germany. His current work investigates psychological meachnisms underlying motivational negative symptoms and interventions in psychotic disorders.

Tania M. Lincoln

Tania M. Lincoln is a clinical psychologist and studied at the Universität Marburg, Germany, where she also did her PhD. Currently she is a full professor at the Universität Hamburg, Germany, and head of the Department for Clinical Psychology and Psychotherapy. Her research focuses on psychological mechanisms and interventions in psychotic disorders.