Periodic Reporting for period 4 - REMOTIVATE (Reward revisited: Towards a comprehensive understanding of motivational influences on human cognition)
Reporting period: 2020-04-01 to 2021-07-31
The REMOTIVATE project aimed to gain a more comprehensive understanding of how reward signals affect human cognition, which is relevant given that reward schemes are pervasive in professional and educational contexts. Reward prospect (monetary incentives) has been shown to improve a diversity of cognitive functions, but research into the underlying mechanisms and boundary conditions of different reward modulations remained scarce. The first focus was the systematic comparison of different cognitive control modes by associating reward to specific task elements and manipulating response types. The second focus was the contribution of affective valence in reward processing, which entailed the comparison between positive and negative reward signals, but also the overlap between reward and affective stimulus processing. These objectives were approached by combining rigorous behavioral testing using different paradigms (i.e. conflict tasks, valence recognition tasks, approach-avoidance tasks, incidental memory tests), as well as neurophysiological measures, i.e. functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and pupillometry, and inter-individual difference measures. First, we found that reward-triggered performance benefits are brought about by cognitive resource allocation if the task allows for preparation, or by seemingly effortless adjustments based on stimulus saliency in tasks requiring immediate responding. Intriguingly, while being beneficial in many cases, these latter adjustments can be detrimental when they are not in line with the task goal. In this case, they require additional cognitive resources to be overruled. Second, our data indicate that positive reward signals (wins) have a similar (or even larger) impact on cognition and performance than losses. Moreover, rewarding and positive affect stimuli share neural processing pathways and trigger similar performance adjustments in different task domains. Considering these parallels, it appears that reward effects on human cognition at least partly rely on the inherent affective valence. Beyond contributing to a more nuanced understanding of human motivation in a controlled lab context, the results of the project can be valuable for applied contexts such as illuminating motivational deficits in neuropsychiatric disorders and improving reward schemes in education and on the work floor. To this end, we fostered clinical collaborations throughout the project and recently started a project line on pro-environmental behavior.
The project was divided into four sub-projects (SP). In SP 1 we compared the effects of positive (win) and negative (loss) reward signals in the context of different cognitive control and response modes. In several behavioral paradigms, we found that reward cues improve performance globally, while reward-related target stimuli promoted valence-action biases (win=approach; loss=avoid). These biases are maladaptive when they are not in line with the task goal - e.g. when an avoid response is required to gain a reward. Neural data (fMRI) revealed that reward cues increase activity in attentional control regions globally, but there was also evidence for interactions where valence-incompatible responses were associated with enhanced neural activity compared to compatible ones, likely reflecting additional resources to overrule the inherent bias.
In SP 2, we investigated the effects of reward signals on cognitive control by embedding win and loss prospect in a conflict task. The main observation was that win and loss stimuli similarly improve performance, which challenges the common view that expected losses have a higher value than equivalent wins. Neurophysiological data from this paradigm (EEG and pupil) supports the notion that win outcomes have a stronger motivational value. A second set of studies focused on the effects of incidental action-outcome contingencies on cognitive control. We found evidence that these can have a selective impact on a certain trial type (i.e. conflict trials). Using a similar design, we tested in how far reward and affective (emotional) outcomes lead to similar performance adjustments (see SP3).
SP 3 further explored the overlap between reward and affective valence both in terms of behavioral and neural modulations. First, we observed similar valence-action biases triggered by the anticipation of affective stimuli, which are comparable to the biases for reward stimuli (SP 1). Second, we found overlapping neural activity modulations (fMRI) for reward-related and affective stimuli when considering their absolute valence (positive vs. negative). Third, we explored potential compatibility effects between reward and affective valence and found that positive affect stimuli facilitate performance in reward trials (compatible valence), while negative affect stimuli impair performance (incompatible valence). These behavioral effects were accompanied by neural modulations indexing effortless versus effortful processing, respectively.
SP 4 focused on the overlap between reward and affective valence in the context of long-term memory by employing an encoding-retrieval procedure (with fMRI during encoding). Behaviorally, we observed that both reward and positive affect improved subsequent retrieval independently. The neural data analysis is still in progress due to a major delay during the covid pandemic in 2020. The analysis will focus on the contribution of two neurotransmitter systems, noradrenalin and dopamine, which both have been implicated in memory processing, as well as processing rewarding and affective stimuli. Finally, in a pilot study we found that white matter integrity in several tracts was inversely related to reward-triggered response speeding, which may reflect higher susceptibility to reward stimuli.
Twelve articles directly emerging from the SPs have been published in peer-reviewed journals. Related studies and collaborations led to 12 additional publications (including 5 in the clinical domain), 3 book chapters, 2 articles in revision, and 1 under review. We have presented the above results at different (inter)national conferences and research facilities, and have organized a symposium.
In SP 2, we investigated the effects of reward signals on cognitive control by embedding win and loss prospect in a conflict task. The main observation was that win and loss stimuli similarly improve performance, which challenges the common view that expected losses have a higher value than equivalent wins. Neurophysiological data from this paradigm (EEG and pupil) supports the notion that win outcomes have a stronger motivational value. A second set of studies focused on the effects of incidental action-outcome contingencies on cognitive control. We found evidence that these can have a selective impact on a certain trial type (i.e. conflict trials). Using a similar design, we tested in how far reward and affective (emotional) outcomes lead to similar performance adjustments (see SP3).
SP 3 further explored the overlap between reward and affective valence both in terms of behavioral and neural modulations. First, we observed similar valence-action biases triggered by the anticipation of affective stimuli, which are comparable to the biases for reward stimuli (SP 1). Second, we found overlapping neural activity modulations (fMRI) for reward-related and affective stimuli when considering their absolute valence (positive vs. negative). Third, we explored potential compatibility effects between reward and affective valence and found that positive affect stimuli facilitate performance in reward trials (compatible valence), while negative affect stimuli impair performance (incompatible valence). These behavioral effects were accompanied by neural modulations indexing effortless versus effortful processing, respectively.
SP 4 focused on the overlap between reward and affective valence in the context of long-term memory by employing an encoding-retrieval procedure (with fMRI during encoding). Behaviorally, we observed that both reward and positive affect improved subsequent retrieval independently. The neural data analysis is still in progress due to a major delay during the covid pandemic in 2020. The analysis will focus on the contribution of two neurotransmitter systems, noradrenalin and dopamine, which both have been implicated in memory processing, as well as processing rewarding and affective stimuli. Finally, in a pilot study we found that white matter integrity in several tracts was inversely related to reward-triggered response speeding, which may reflect higher susceptibility to reward stimuli.
Twelve articles directly emerging from the SPs have been published in peer-reviewed journals. Related studies and collaborations led to 12 additional publications (including 5 in the clinical domain), 3 book chapters, 2 articles in revision, and 1 under review. We have presented the above results at different (inter)national conferences and research facilities, and have organized a symposium.
The project moved beyond the state of the art by investigating reward effects at the intersection with other cognitive phenomena and paradigms. Specifically, it features a systematic combination of reward manipulations and different interrelated factors, such as affective valence, response types, and control modes to move beyond the notion of an isolated “reward homunculus”. In this regard, behavioral paradigms were combined with different neurophysiological measures, which contribute to a more nuanced picture of the underlying mechanisms. Without reiterating the details, we found that reward-triggered performance modulations can be brought about in the presence or absence of controlled processes, depending on the nature of the task. Intriguingly, the more effortless adjustments can be detrimental when they are not in line with the task goal. We also observed striking parallels between reward an affective processing across several paradigms. These observations challenge the view that a) reward manipulations are primarily beneficial and b) the unique status of reward in the context of cognitive performance modulations. Finally, throughout the project we promoted open science practices in the lab.