fMRI evidence for strategic decision-making during resolution of pronoun reference

Abstract

Pronouns are extraordinarily common in daily language yet little is known about the neural mechanisms that support decisions about pronoun reference. We propose a large-scale neural network for resolving pronoun reference that consists of two components. First, a core language network in peri-Sylvian cortex supports syntactic and semantic resources for interpreting pronoun meaning in sentences. Second, a frontal-parietal network that supports strategic decision-making is recruited to support probabilistic and risk-related components of resolving a pronoun’s referent. In an fMRI study of healthy young adults, we observed activation of left inferior frontal and superior temporal cortex, consistent with a language network. We also observed activation of brain regions not associated with traditional language areas. By manipulating the context of the pronoun, we were able to demonstrate recruitment of dorsolateral prefrontal cortex during probabilistic evaluation of a pronoun’s reference, and orbital frontal activation when a pronoun must adopt a risky referent. Together, these findings are consistent with a two-component model for resolving a pronoun’s reference that includes neuroanatomic regions supporting core linguistic and decision-making mechanisms.

Syntactic processing is distributed across the language system

“…Namely, whereas we have here focused on the regions of the language system, syntactic complexity manipulations also produce responses in the regions of the domain-general fronto-parietal “multiple demand (MD)” system (e.g., Barde, Yeatman, Lee, Glover, & Feldman, 2012), and damage to some MD regions can lead to difficulties with syntactically complex structures (e.g., Amici et al , 2007). More generally, MD regions respond to diverse executive tasks (e.g., Duncan & Owen, 2001; Corbetta & Shulman, 2002; Duncan, 2010; Fedorenko et al , 2013) across many domains, including language (e.g., Rodd, Davis, & Johnsrude, 2005; Novais-Santos et al , 2007; January, Trueswell, & Thompson-Schill, 2009; McMillan, Clark, Gunawardena, Ryant, & Grossman, 2012; McMillan et al , 2013; Nieuwland, Martin, & Carreiras, 2012; Wild et al , 2012). An important goal for future work is thus to understand the division of labor between language and MD regions during syntactic processing (see also Fedorenko, 2014, for discussion).…”

The N400 in processing repeated name and pronoun anaphors in sentences and discourse

“…Because the Nref has been suggested to mark referential ambiguity (Nieuwland, 2014; Van Berkum et al, 1999), its presence after both repeated full names and pronouns in the conjoined conditions suggests that readers may have been uncertain about whether the repeated name anaphor would end up referring to just one of the nouns or to the entire conjoined noun phrase. Additionally, while there are important differences between the timing of the EEG and BOLD signal, as well as limitations inherent in localizing ERP components, the Nref may be related to activity in the frontal cortex that has been shown to play a crucial role in the decision-making aspect of referring and assigning new reference (Nieuwland, Petersson, & Van Berkum, 2007; McMillan et al, 2012). …”

“…Similarly, McMillan, Clark, Gunawardena, Ryant, and Grossman (2012) showed that processing ambiguous referents evoke more frontal activity (the dorsolateral prefrontal cortex in particular) than processing non-ambiguous ones. While our focus in this paper is on the time course and ERP components involved in reference processing, we consider the implications of these various findings for the neural bases of reference processing in the general discussion.…”

Beyond words: Pragmatic inference in behavioral variant of frontotemporal degeneration

“…In this context, bvFTD patients appear to have minimal self-evaluation (Massimo et al, 2013; Rosen et al, 2010), and thus they may be less likely to evaluate the reasonableness of their responses. Likewise, they may have limited concern about the reward associated with a correct response or a penalty associated with an incorrect response (Grossman et al, 2010; McMillan, Clark, Gunawardena, Ryant, & Grossman, 2012). Additional work is needed to evaluate these possibilities.…”