The ventrolateral prefrontal cortex facilitates processing of sentential context to locate referents

Abstract

Left ventrolateral prefrontal cortex (VLPFC) has been implicated in both integration and conflict resolution in sentence comprehension. Most evidence in favor of the integration account comes from processing ambiguous or anomalous sentences, which also poses a demand for conflict resolution. In two eye-tracking experiments we studied the role of VLPFC in integration when demands for conflict resolution were minimal. Two closely-matched groups of individuals with chronic post-stroke aphasia were tested: the Anterior group had damage to left VLPFC, whereas the Posterior group had left temporo-parietal damage. In Experiment 1 a semantic cue (e.g., “She will eat the apple”) uniquely marked the target (apple) among three distractors that were incompatible with the verb. In Experiment 2 phonological cues (e.g., “She will see an eagle.” / “She will see a bear.”) uniquely marked the target among three distractors whose onsets were incompatible with the cue (e.g., all consonants when the target started with a vowel). In both experiments, control conditions had a similar format, but contained no semantic or phonological contextual information useful for target integration (e.g., the verb “see”, and the determiner “the”). All individuals in the Anterior group were slower in using both types of contextual information to locate the target than were individuals in the Posterior group. These results suggest a role for VLPFC in integration beyond conflict resolution. We discuss a framework that accommodates both integration and conflict resolution.

A common neural hub resolves syntactic and non-syntactic conflict through cooperation with task-specific networks

“…These are certainly important findings; however, as maintained throughout this paper, we caution against drawing strong conclusions about domain-specificity from non-significant correlations for theoretical reasons (see e.g., Miyake & Friedman, 2004). Other studies, moreover, do show clear correlations between sentence comprehension and non-verbal cognitive control (e.g., Nozari et al, 2016), so the findings on this issue are mixed. Here, we argue for domain-generality in LIFG that is unconstrained by syntactic boundaries, but future work should extend our approach to test how the combined co-localization and connectivity findings are modulated across verbal and non-verbal lines.…”

“…That is, the materials for our language task were designed to compare syntactically ambiguous to syntactically unambiguous sentences, to identify whether syntactic conflict engages a brain region that is involved in handling conflict in non-syntactic tasks, not whether simple sentence processing (absent conflict) draws on the MD system or the LIFG. While there may be some functional-anatomical specificity for language (and more specifically, syntactic) processing, some linguistic tasks also theoretically require domain-general input from the neurobiological “hub” that handles information-processing conflict (for reviews, see Novick, Trueswell, & Thompson-Schill, 2010; Novick et al, 2005; Nozari & Thompson-Schill, 2015; see also January et al, 2009; Novick et al, 2009, 2014; Nozari, Mirman, & Thompson-Schill, 2016; Ye & Zhou, 2009). …”

“…As intimated in the prior example, some researchers have hypothesized that one important cognitive control function may be to resolve incompatible representations of sentence meaning that arise due to the incremental nature of comprehension (Novick, Trueswell, & Thompson-Schill, 2005; Nozari, Mirman, & Thompson-Schill, 2016; see also Kaan & Swaab, 2002). Specifically, the control procedures that operate over syntactic material may be general-purpose in nature, engaging the same prefrontal brain systems that detect and resolve information-conflict in other domains such as recognition memory, when familiar-but-irrelevant memoranda interfere with target identification (as in the doppelgänger example above; Jonides & Nee, 2006; Nee, Jonides, & Berman, 2007).…”

The interplay of local attraction, context and domain-general cognitive control in activation and suppression of semantic distractors during sentence comprehension

“…Yet theories of sentence comprehension have disagreed on whether contextual information is consulted early or late during processing (see Dahan & Tanenhaus, 2004 for a review of competing accounts). In addition, in spite of growing evidence for the involvement of cognitive control in various aspects of sentence and discourse processing (Novick, Kan, Trueswell, & Thompson-Schill, 2009; Nozari, Arnold, & Thompson-Schill, 2014; Nozari, Mirman, & Thompson-Schill, 2016; Nozari & Thompson-Schill, 2015), the link between control processes and inhibition of context-incompatible information has received little attention (but see Brown-Schmidt, 2009; Nilsen & Graham, 2009). Critically, it is unclear whether inhibitory resources regulate the constraining effect of context, and whether such resources are shared between linguistic and non-linguistic domains or are domain-specific.…”

“…While there is solid evidence for the involvement of control processes in comprehension (e.g., Nozari et al, 2016; Sommers & Danielson, 1999; see Novick, Hussey, Teubner-Rhodes, Harbison, & Bunting, 2014; Novick, Kan, Trueswell, & Thompson-Schill, 2009 for reviews), relatively little work has explored the role and nature of such processes in limiting the consideration of context-incompatible information. An exception is a recent study by Brown-Schmidt (2009; see also Nilsen & Graham, 2009 for a similar concept in children).…”