Reinforcement learning in young adults with developmental language impairment

Abstract

The aim of the study was to examine reinforcement learning (RL) in young adults with developmental language impairment (DLI) within the context of a neurocomputational model of the basal ganglia-dopamine system (Frank et al., 2004). Two groups of young adults, one with DLI and the other without, were recruited. A probabilistic selection task was used to assess how participants implicitly extracted reinforcement history from the environment based on probabilistic positive/negative feedback. The findings showed impaired RL in individuals with DLI, indicating an altered gating function of the striatum in testing. However, they exploited similar learning strategies as comparison participants at the beginning of training, reflecting relatively intact functions of the prefrontal cortex to rapidly update reinforcement information. Within the context of Frank’s model, these results can be interpreted as evidence for alterations in the basal ganglia of individuals with DLI.

Sentence Repetition Accuracy in Adults With Developmental Language Impairment: Interactions of Participant Capacities and Sentence Structures

“…Other studies of adults with DLI have also found that adults with DLI score lower on tests of PIQ (Fidler et al, 2011;Lee & Tomblin, 2012;Rost & McGregor, 2012) and have lower educational attainment (Conti-Ramsden & Durkin, 2012). This suggests that our group with DLI was representative of the population of adults with DLI; however, the group with typical language had several members with higher than typical PIQ.…”

“…The group with DLI differed from the group with typical language in both language ability and PIQ. This has frequently been the case in studies of adults with DLI (Fidler et al, 2011;Lee & Tomblin, 2012;Rost & McGregor, 2012;Tomblin et al, 1992). Because somewhat lower PIQ is characteristic of adults with DLI, matching on PIQ risks creating groups that are not representative of the population.…”

“…As a result, studies have not matched adults with DLI to peers with typical language on nonverbal intelligence (Fidler, Plante, & Vance, 2011;Lee & Tomblin, 2012;Tomblin et al, 1992). In fact, researchers have argued that matching or statistically controlling for nonverbal ability may result in groups that are no longer representative of the populations they are meant to represent (Dennis et al, 2009).…”

“…Studies have shown that children (Kemeny & Lukacs, 2010;Lum, Gelgic, & Conti-Ramsden, 2010), adolescents (Tomblin, Mainela-Arnold, & Zhang, 2007), and adults (Lee & Tomblin, 2012) with DLI have more limited procedural memory ability for verbal information. Findings are less consistent with the PDH when the procedural memory task involves nonverbal information (Lum & Conti-Ramsden, 2013) or when the task does not involve learning discrete sequences (Hsu & Bishop, 2014).…”

The minority report: some common assumptions to reconsider in the modelling of the brain and behaviour

“…For instance, with regard to the posited role of the basal ganglia in language acquisition and use, an impairment of RL in general appears to accompany developmental language impairment (Lee & Tomblin, 2012). 18 Likewise, with regard to the posited involvement of the hippocampus in language acquisition (Edelman, 2011), individual differences in hippocampal neuroanatomy in infancy predict language performance a few months later (Can, Richards, & Kuhl, 2013).…”