Specifying the role of the left prefrontal cortex in word selection

Abstract

Word selection allows us to choose words during language production. This is often viewed as a competitive process wherein a lexical representation is retrieved among semantically-related alternatives. The left prefrontal cortex (LPFC) is thought to help overcome competition for word selection through top-down control. However, whether the LPFC is always necessary for word selection remains unclear. We tested 6 LPFC-injured patients and controls in two picture naming paradigms varying in terms of item repetition. Both paradigms elicited the expected semantic interference effects (SIE), reflecting interference caused by semantically-related representations in word selection. However, LPFC patients as a group showed a larger SIE than controls only in the paradigm involving item repetition. We argue that item repetition increases interference caused by semantically-related alternatives, resulting in increased LPFC-dependent cognitive control demands. The remaining network of brain regions associated with word selection appears to be sufficient when items are not repeated.

Facilitation and interference in naming: A consequence of the same learning process?

“…Blocked-cyclic and continuous naming tasks are used often interchangeably to draw inferences about the nature of semantic interference effects in naming and the processes that underlie speech production in general (Blocked Cyclic Naming: e.g., Belke, 2008, 2013; Damian & Als, 2005; de Zubicaray et al, 2014; Meinzer et al, 2016; Navarrete, Mahon, Lorenzoni, & Peressotti, 2016; Schnur et al, 2006, 2009; Continuous Naming: e.g., Belke, 2013; Canini et al, 2016; Howard et al, 2006; Navarrete et al, 2010; Ries et al, 2015; Rose & Abdel Rahman, 2016a, b; Schnur, 2014). While previous research has discussed the extent to which these two tasks may or may not reflect the same processes (Belke & Stielow, 2013), to our knowledge, this is the first study which provides a direct empirical comparison of semantic interference effects across these two tasks.…”

“…Additionally, given that each task differs in how it elicits semantic interference (organization of related items, repetition of items) and differs in the degree to which it recruits working memory resources (Belke, 2008; Belke & Stielow, 2013), there is further question as to whether these tasks are as similar as has been proposed (see also Belke, 2013; Navarrete et al, 2012; Navarrete, Del Prato, Peressotti, & Mahon, 2014; Riley, McMahon, & de Zubicaray, 2015). Understanding whether semantic interference is caused by the same mechanism is important because these paradigms and semantic interference effects in general are used to test theories of the cognitive architecture in language production (e.g., Dell, Oppenheim, & Kittredge, 2008; Rapp & Goldrick, 2000; Levelt, Roelofs, & Meyer, 1999; Schnur et al, 2006), comprehension (e.g., Campanella & Shallice, 2011; Crutch, Connell, & Warrington, 2009; Wei & Schnur, 2016) and deficits in executive control (e.g., Biegler, Crowther, & Martin, 2008; Harvey & Schnur, 2015; Jefferies, Baker, Doran, & Ralph, 2007; Ries, Karzmark, Navarrete, Knight, & Dronkers, 2015; Schnur et al, 2009). …”

The Role of Task-Specific Response Strategies in Blocked-Cyclic Naming

“…Belke (2008) has shown that when speakers’ working memory is loaded by a concurrent digit retention task, they display bigger context effects, arguably because they are less efficient at biasing the set members top-down. Likewise, patients suffering from neurological damage to these left frontal areas show cumulative semantic context effects in blocked-cyclic naming, arguably because their ability to bias relevant set members top-down is impaired (see Belke and Stielow, 2013; but see Ries et al, 2015). So far, Howard et al (2006), Oppenheim et al (2010), and Navarrete et al (2014) have not addressed how their accounts would explain these findings for healthy and impaired speakers and for blocked as compared to continuous manipulations of semantic context.…”

Effects of Bilingualism on Verbal and Nonverbal Memory Measures in Mild Cognitive Impairment

“…Moreover, Antón-Méndez and Gollan (2010) showed that bilinguals and monolinguals differed in the type of responses on a word association task. Bilinguals were more likely to produce responses not listed in the norms than were monolinguals, suggesting that bilingualism influences the nature of lexical–semantic representations which may determine word selection (Riès, Karzmark, Navarrete, Knight, & Dronkers, 2015). The semantic interference effect could be explained by changes in the relationship between such semantic and lexical representations (Navarrete, Del Prato, & Mahon, 2012).…”