Contributions of memory circuits to language: the declarative/procedural model

Abstract

The structure of the brain and the nature of evolution suggest that, despite its uniqueness, language likely depends on brain systems that also subserve other functions. The declarative/procedural (DP) model claims that the mental lexicon of memorized word-specific knowledge depends on the largely temporal-lobe substrates of declarative memory, which underlies the storage and use of knowledge of facts and events. The mental grammar, which subserves the rule-governed combination of lexical items into complex representations, depends on a distinct neural system. This system, which is composed of a network of specific frontal, basal-ganglia, parietal and cerebellar structures, underlies procedural memory, which supports the learning and execution of motor and cognitive skills, especially those involving sequences. The functions of the two brain systems, together with their anatomical, physiological and biochemical substrates, lead to specific claims and predictions regarding their roles in language. These predictions are compared with those of other neurocognitive models of language. Empirical evidence is presented from neuroimaging studies of normal language processing, and from developmental and adult-onset disorders. It is argued that this evidence supports the DP model. It is additionally proposed that "language" disorders, such as specific language impairment and non-fluent and fluent aphasia, may be profitably viewed as impairments primarily affecting one or the other brain system. Overall, the data suggest a new neurocognitive framework for the study of lexicon and grammar.

Implicit learning seems to come naturally for children with autism, but not for children with specific language impairment: Evidence from behavioral and ERP data

“…Ullman described that language learning involves both procedural (or implicit) memory involving frontal/basal ganglia circuits, particularly the nigro‐striatal system, and declarative (or explicit) memory mainly relying on hippocampal structures [Ullman, 2004]. Based on findings of a Go‐NoGo study including patients with basal ganglia disorders, it has been suggested that the N2 is associated with the nigo‐striatal system for pre‐motor inhibition, whereas the P3 is more associated with the mesocortico‐limbic system involved in outcome monitoring [Beste, Willemssen, Saft, & Falkenstein, 2010].…”

“…Explicit learning relies mainly on the Medial Temporal Lobe, including the hippocampus, with connections to other brain areas such as the prefrontal cortex [e.g., Reber, 2013]. However, it has been found that in some situations the hippocampus is also involved in implicit learning [e.g., Hannula & Greene, 2012; Poldrack & Rodriguez, 2003], and that the neural networks of implicit and explicit learning interact [Destrebecqz et al, 2005; Ullman, 2004]. Thus, the different neural networks involved in implicit and explicit learning can overlap and interact depending on the learning task.…”

Rule and similarity in grammar: Their interplay and individual differences in the brain

“…aaf gum *aaf trul pel rüfi). The reader is referred to previous studies (Opitz & Friederici, 2003;2004) employing this artificial language for further examples and a schematic presentation of the underlying grammar system.…”

Syntactic and thematic components of sentence processing in progressive nonfluent aphasia and nonaphasic frontotemporal dementia

“…Consistent with previous findings, however, PNFA patients were not sensitive to either class of syntactic error (morphosyntactic or word class substitution errors). One possible explanation is that the rule governing regular verb morphological processing (adding "-ed" to the citation form of the verb) is degraded or cannot be processed in these patients (Ullman, 2004;Ullman et al, 1997), although other data conflicts with this interpretation (Ash, Koenig, Moore, & Grossman, submitted;Bird, Lambon Ralph, Seidenberg, McClelland, & Patterson, 2003;Patterson, Lambon Ralph, Hodges, & McClelland, 2001). …”