The language network reliably ‘tracks’ naturalistic meaningful non-verbal stimuli

Abstract

The language network, comprised of brain regions in the left frontal and temporal cortex, responds robustly and reliably during language comprehension but shows little or no response during many non-linguistic cognitive tasks (e.g., Fedorenko & Blank, 2020). However, one domain whose relationship with language remains debated is semantics—our conceptual knowledge of the world. Given that the language network responds strongly to meaningful linguistic stimuli, could some of this response be driven by the presence of rich conceptual representations encoded in linguistic inputs? In this study, we used a naturalistic cognition paradigm to test whether the cognitive and neural resources that are responsible for language processing are also recruited for processing semantically rich non-verbal stimuli. To do so, we measured BOLD responses to a set of ∼5-minute-long video and audio clips that consisted of meaningful event sequences but did not contain any linguistic content. We then used the inter-subject correlation (ISC) approach (Hasson et al., 2004) to examine the extent to which the language network ‘tracks’ these stimuli. Across all the regions of the language network, non-verbal meaningful stimuli elicited reliable ISCs. These ISCs were higher than the ISCs elicited by non-verbal stimuli without semantic content (e.g., a music clip), but substantially lower than the ISCs elicited by linguistic stimuli. Our results complement earlier findings from controlled experiments (e.g., Ivanova et al., 2021) in providing further evidence that the language network responds to meaningful content in non-verbal stimuli.

The human language system, including its inferior frontal component in ‘Broca’s area’, does not support music perception

“…The current results add to the growing body of evidence that the left-lateralized fronto-temporal brain network that supports language processing is highly selective for linguistic input (e.g., Fedorenko et al 2011; Monti et al 2009, 2012; Deen et al 2015; Pritchett et al 2018; Jouravlev et al 2019; Ivanova et al 2020, 2021; Benn, Ivanova et al 2021; Liu et al 2020; Deen and Freiwald 2021; Paunov et al 2022; Sueoka et al 2022; see Fedorenko and Blank 2020 for a review) and not critically needed for many forms of complex cognition (e.g., Lecours and Joanette 1980; Varley and Siegal 2000; Varley et al 2005; Apperly et al 2006; Woolgar et al 2018; Ivanova et al 2021; see Fedorenko and Varley 2016 for a review). Importantly, this selectivity holds across all components of the language network, including the parts that fall within ‘Broca’s area’ in the left inferior frontal gyrus.…”

“…Across three fMRI experiments, we obtained a clear answer: the brain regions of the language network, which support the processing of linguistic syntax (e.g., Fedorenko et al 2010Pallier et al 2011;Bautista and Wilson 2016;Blank et al 2016), do not support music processing (see Table 7 for a summary of the results). We found overall low responses to music (including orchestral pieces, solo pieces played on different instruments, synthetic music, and vocal music) in the language brain regions (Figure 3; see Sueoka et al 2022, for complementary evidence from the intersubject correlation approach applied to a rich naturalistic music stimulus), including in speakers of a tonal language (Figure 6), and no consistent sensitivity to manipulations of music structure (Figure 4). We further found that the ability to make well-formedness judgments about the tonal structure of music was preserved in patients with severe aphasia who cannot make grammaticality judgments for sentences (Figure 5), although we acknowledge the possibility that general ability to detect unexpected events may have contributed to performance on the critical music-structure tasks (e.g., Bigand et al 2014;Collins et al 2014) and that additional controls would be needed to conclusively determine whether these patients have preserved music-structure processing abilities.…”

“…Although it is certainly possible that some aspects of linguistic and/or musical processing would require domain-general executive resources, based on the available evidence from the domain of language, we would argue that any such engagement does not reflect the engagement of computations like syntactic structure building. In particular, Blank and Fedorenko (2017) found that activity in the brain regions of the domain-general MD network does not closely ‘track’ linguistic stimuli, as evidenced by low inter-subject correlations during the processing of linguistic input (see Paunov et al 2021 and Sueoka et al 2022 for replications). Further, Diachek, Blank, Siegelman et al (2020) showed in a large-scale fMRI investigation that the MD network is not engaged during language processing in the absence of secondary task demands (cf.…”

Precision fMRI reveals that the language-selective network supports both phrase-structure building and lexical access during language production

“…And in the visual event semantics (VisEvSem) condition, participants viewed photographs of events (as in SProd) and were asked to indicate whether the depicted event takes place indoors or outdoors (a relatively high-level judgment that requires visual event perception and also draws on world knowledge) via a two-choice button box (Figure 1a-iv). This condition targets visual and conceptual processing of events and was included to ensure that responses to the SProd condition, which uses these pictorial stimuli, were not due to these cognitive processes (see e.g., Ivanova et al, 2021 andSueoka et al, 2022 for some evidence of engagement of the language areas in visual event semantics).…”

The spatiotemporal dynamics of semantic integration in the human brain

“…Much work into linguistic coherence has utilized scalp event-related potentials or fMRI (Boudewyn et al, 2012; Camblin et al, 2007; Ferstl and von Cramon, 2002; Jouen et al, 2021), which lack the fine spatiotemporal resolution needed to comprehensively map cortical responses. Under some analyses, the cortical substrates for language and semantic processing overlap (Ivanova et al, 2021; Sueoka et al, 2022), while others point to dissociability (Colvin et al, 2019).…”