Relevance Acquisition through Motivational Incentives

Abstract

Motivational relevance associated with symbolic stimuli impacts both neural and behavioral responses, similarly to visual stimuli that have inherent emotional valence. However, the specific effects of associated relevance on early sensory stages and lexico-semantic processing of these stimuli, particularly considering the role of low-level visual features in relevance acquisition, remain unclear. To address these questions, we employed an associative learning paradigm where we manipulated visual features, but not the stimuli themselves. The study (N = 48) included a learning session, where pseudowords were associated with either gain, loss, or neutral outcomes. This was followed by a test session the next day, involving an old/new decision task, in which stimuli were presented in either in the same or a different font. During both sessions, pupil responses and Event-related Brain Potentials (P1, EPN, LPC, P3) were measured. Stronger pupil responses and increased neural activation in early visual encoding (P1) and lexico-semantic processing (EPN) were observed during the acquisition of relevance, particularly for loss associations. Interestingly, after relevance acquisition, the most substantial effect on modulating lexico-semantic processing was observed for gain associations, evident in both behavioral responses and neural activity. During the test phase, exposure to incongruent visual features of the stimuli influenced the same processes that were observed during relevance acquisition. Notably, these effects of visual feature congruence were independent of those of associated motivational relevance. These results highlight the dynamic nature of motivational relevance effects, revealing differential effects observed during acquisition and the test phase, as well as between earlier perceptual processing and later neural and behavioral responses.