The Role of Reward in Word Learning and Its Implications for Language Acquisition

Abstract

The exact neural processes behind humans' drive to acquire a new language--first as infants and later as second-language learners--are yet to be established. Recent theoretical models have proposed that during human evolution, emerging language-learning mechanisms might have been glued to phylogenetically older subcortical reward systems, reinforcing human motivation to learn a new language. Supporting this hypothesis, our results showed that adult participants exhibited robust fMRI activation in the ventral striatum (VS)--a core region of reward processing--when successfully learning the meaning of new words. This activation was similar to the VS recruitment elicited using an independent reward task. Moreover, the VS showed enhanced functional and structural connectivity with neocortical language areas during successful word learning. Together, our results provide evidence for the neural substrate of reward and motivation during word learning. We suggest that this strong functional and anatomical coupling between neocortical language regions and the subcortical reward system provided a crucial advantage in humans that eventually enabled our lineage to successfully acquire linguistic skills.

Beta oscillations and reward processing: Coupling oscillatory activity and hemodynamic responses

“…However, the effects of monetary gains in gambling tasks-which we replicate here-are very robust and have been widely studied both in EEG and fMRI (Camara et al, , 2010Ripollés et al, 2014;Carlson et al, 2011;Marco-Pallarés et al, 2008Sescousse et al, 2013;Cohen et al, 2007;Padrao et al, 2013). In addition, in the gambling task used in this study, the amounts of overall monetary gains and losses were fixed and equal for all participants and sessions.…”

“…2B and Table 1). At the selected threshold, the Loss N Gain contrast yielded no significant activations, suggesting that a similar brain network is involved in processing both gains and losses but with a differential amount of activation (increasing with gains and decreasing with losses; Dreher, 2007;Tom et al, 2007;Ripollés et al, 2014;Càmara et al, 2009 andCàmara et al, 2010). Thus, this contrast was not further analyzed.…”

Neural correlates of specific musical anhedonia

“…These cortical-subcortical impoverished interactions could be crucial for the correct attainment of language learning milestones, probably because of the reduced capacity in these children to experience auditory processing and language learning experiences as rewarding (43). On the other hand, enhancements to this system may be observed in musicians.…”

Neurobiological Basis of Language Learning Difficulties

“…Recent work shows that creating sound–meaning links also recruits the striatum. The ventral striatum (nucleus accumbens) is activated as these links are learned, suggesting a role for reward-based circuitry in learning novel words [55]. The dorsal striatum also responds to feedback in verbal paired-associate tasks [56], especially when participants believed that the feedback was indicative of achievement [57].…”