“Wanted!” The effects of reward on face recognition: electrophysiological correlates

Abstract

The aim of the present study was to uncover the temporal dynamics of face recognition as a function of reward. Event-related potentials (ERPs) were recorded during the encoding and the subsequent old/new memory test in response to faces that could be associated with a monetary reward. The behavioral results showed that faces associated with reward at both encoding and retrieval were recognized better than the unrewarded ones. ERP responses highlighted that successful encoding predictive of subsequent memory was greater for faces associated with reward than for faces without reward-driven motivational learning. At retrieval, an early positive-going component was elicited for potentially rewarded faces on frontal regions, while the occipito-temporal N170 component showed priming effects as a function of reward. Later on, larger centro-parietal ERP components, related to recognition memory, were found selectively for reward-associated faces. Remarkably, electrophysiological responses varied in a graded manner, with the largest amplitude yielded by faces with double reward, followed by faces associated with reward only at encoding. Taken together, the present data show that the processing of outcome expectations affects face structural encoding and increases memory efficiency, yielding a robust and sustained modulation over frontal and temporal areas where reward and memory mechanisms operate in conjunction.

Reward modulates the neural dynamics of early visual category processing

“…Unexpectedly, however, this effect was limited to faces and did not extend to scene stimuli. While previous studies on similar tasks have used either faces (Marini et al, 2011) or scenes (Bunzeck et al, 2009) our results seem to suggest that when being used within one experimental session reward can have selective effects on reaction-times. This might, for instance, relate to differences in the biological significance of both stimulus categories (Park et al, 2010) and remains to be further explored.…”

“…4D). Indeed, earlier EEG studies on the link between reward and declarative memory have found similar response patterns (Gruber and Otten, 2010;Marini et al, 2011) and they suggest that neural activity over prefrontal sensors plays a critical role for improved learning by reward.…”

“…We expected early category sensitive ERF-components (i.e., M100 and M170) to be increased by reward (i.e., higher amplitudes in experiment 1 vs. 2) and that this effect could be source localized to the lateral occipital cortex (M100) and fusiform gyrus (M170). Furthermore, we also predicted improved recognition memory by reward prospect (Adcock et al, 2006) and further explored the temporal characteristics of the underlying neural mechanisms (Gruber and Otten, 2010;Marini et al, 2011).…”

Utilization of reward-prospect enhances preparatory attention and reduces stimulus conflict

“…With respect to the target, this enhanced N2 also indicates that participants were able to rapidly boost early processing of relevant information if they are cued with reward information. The early occipital brain activity was again paired with a frontal positivity and was followed by a notably more frontal P3 wave, perhaps a P3a like component (Luck, 2004; Luck & Kappenman, 2011; Polich, 2007), which would appear to reflect the reward-related boosting to improve processing of the target (Krebs et al, 2013; Goldstein et al, 2006; Marini, Marzi & Viggiano, 2011; Wu & Zhou, 2009). …”

Reward prospect interacts with trial-by-trial preparation for potential distraction

“…The incentive role of reward and its effects on behavior can be achieved through modulations of attentional and cognitive control. These modulations include enhancing attentional preparation under conditions of reward prospect (Van den Berg et al, 2014), enhanced recruitment of cognitive resources (Krebs, Boehler, Roberts, Song, & Woldorff, 2012; Vassena, Silvetti, Boehler, Achten, Fias et al, 2014), reduction of conflict (Padmala & Pessoa, 2011; Krebs, Boehler, & Woldorff, 2010), stopping-induced stimulus devaluation (Wessel, O'Doherty, Berkebile, Linderman & Aron, 2014), reactive response inhibition (Boehler, Schevernels, Hopf, Stoppel, & Krebs, 2014), and optimized memory encoding (Marini, Marzi, & Viggiano, 2011). Moreover, the Eriksen flanker task in association with monetary rewards has been already used in previous studies of selective attention (Seifert et al 2006; Hubner & Schlosser, 2010), cognitive control (Braem, Hickey, Duthoo & Notebaert, 2014) and conflict adaptation (van Steenbergen, Band & Hommel, 2009; Braem, Vertguts, Roggeman & Notebaert, 2012), suggesting the usefulness of this paradigm for the goals of the present study.…”