Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - REMOTIVATE (Reward revisited: Towards a comprehensive understanding of motivational influences on human cognition)

Teaser

REMOTIVATE aims to gain a more comprehensive understanding of motivation effects on human cognition. Motivation (as triggered by extrinsic rewards) has shown to improve a diversity of cognitive functions, ranging from visual attention over conflict resolution and response...

Summary

REMOTIVATE aims to gain a more comprehensive understanding of motivation effects on human cognition. Motivation (as triggered by extrinsic rewards) has shown to improve a diversity of cognitive functions, ranging from visual attention over conflict resolution and response inhibition to memory formation. Since these effects have most often been observed in isolation, it still remains unclear to what extend the cognitive benefits rely on a common mechanism or whether reward acts in a function-specific manner. Moreover, reward-based modulations can only be understood when considering other interrelated factors, such as the control mode (pro-active or. re-active) or the response type (press or inhibit; approach or avoid) of a certain task. Third, while motivation has an intuitive overlap with emotion processing, especially with regard to ‘natural’ valence-action mappings, these two domains have typically been studied in isolation. The present project systematically combines reward manipulations with the before mentioned interrelated factors to understand how reward can guide (or misguide) cognitive operations and ultimately affect behavior. Considering that motivational processes are disturbed in a number of neuropsychiatric disorders, like attention-deficit hyperactivity disorder, addiction, and Parkinson’s disease, the project may help to further illuminate the nature of such impairments and to develop more targeted therapeutic approaches. Intriguingly, these disorders have been related to disturbances in the dopaminergic and/or the noradrenergic system, which are the very same systems that are also thought to be vital for the cognitive benefits of reward observed in the healthy mind. Hence, in order to understand the above relationships on a neuromechanistic level, it is critical to employ optimized neuroimaging methods that allow for a reliable, yet non-invasive investigation of neural activity in the brain regions that are implicated in reward and emotion processing, as well as regions associated with specific cognitive functions that can be modulated by reward.

Work performed

During the past 18 months, three out of four sup-projects have been initiated, each spear-headed by one team member (two PhD students and one postdoc). The main focus of project 1 is the interplay between pro-active and re-active reward manipulations, and how these may differentially affect valence-action biases. Specifically, we compared the effects of reward/punishment cues (pro-active) versus reward-/punishment-related target features (re-active) in a series of behavioral experiments. A second study line investigates similar effects with emotion-related cues and targets in the absence of extrinsic reward. Project 2 investigates the effects of relevant versus irrelevant reward and emotion signals on cognitive control. One study line focuses on the overlap between learned reward and emotion signals, and another set of studies compares the influence of reward and punishment manipulations in a conflict task, with extension to computational modeling. For project 3, we have piloted and conducted an fMRI study which directly compares the processing of reward-based and emotion-based valence and the effect on subsequent conflict processing. The fMRI study included recordings of cardiac and respiratory data, which were then used for physiological artefact correction to increase the signal-to-noise ratio in small subcortical regions. This is a major achievement as the acquisition protocol and analysis pipeline will be adopted for all subsequent fMRI studies. Beyond these main projects, several additional exploratory pilot studies and affective rating studies were performed by the team members. Two behavioral manuscripts (projects 1 and 2) and one fMRI manuscript (project 3) will soon be sent out for peer review. I have moreover worked on additional related projects, one of which has resulted in a recent publication in a peer-reviewed journal, and written a book chapter on reward effects in cognitive control. Moreover, the postdoc and I presented different results of the project at national and international scientific meetings, and the PhD students presented their work at a national expert workshop.

Final results

The project steps on new ground with respect to different aspects. First, it features a systematic combination of reward manipulations and different interrelated factors, such as emotional valence, action tendencies, and control modes to move beyond the notion of an isolated “reward homunculus”. To this end, we implement for example closely matched paradigms to investigate the overlap between reward and emotional valence processing, which have typically been studied in separate research lines. This is not only relevant at the conceptual level, but also with regard to the underlying neural mechanisms. One focus of the project is to study the joint contribution of two important neurotransmitter systems (dopamine and noradrenalin) to the implementation of reward-based performance changes, again considering interrelated factors which may rely on the same systems. In order to assess neural activity modulations, especially in small subcortical regions, the project employs modern neuroimaging approaches, including high-resolution fMRI with physiological noise correction. Moreover, standard analyses will be complemented with multivariate approaches and computational modeling, and we aim to integrate results from different imaging modalities, i.e., fMRI, EEG, and pupil dilation measures to gain insights into the spatial and temporal dynamics of the underlying processes. The integrative nature of the project is further mirrored in the layout of the sub-projects, in that the results of one project will inform and complement studies of the other projects – both in terms of content and methods. The result of the project can be highly valuable for different applied contexts, the most important ones being the transfer of our insights to neuropsychiatric disorders and the implementation of reward schemes in education. Moreover, insights on how rewards are translated into behavioral changes are very interesting for occupational contexts, e.g., in terms of improving efficiency, commitment, and work-life-balance, and even safety. For all these contexts, it is key that the present projects not only investigates reward-based benefits, but also under which circumstances reward manipulations can in fact impair performance or even lead to dysfunctional behavior.