The visual word form area (VWFA) is part of both language and attention circuitry

Abstract

While predominant models of visual word form area (VWFA) function argue for its specific role in decoding written language, other accounts propose a more general role of VWFA in complex visual processing. However, a comprehensive examination of structural and functional VWFA circuits and their relationship to behavior has been missing. Here, using high-resolution multimodal imaging data from a large Human Connectome Project cohort (N = 313), we demonstrate robust patterns of VWFA connectivity with both canonical language and attentional networks. Brain-behavior relationships revealed a striking pattern of double dissociation: structural connectivity of VWFA with lateral temporal language network predicted language, but not visuo-spatial attention abilities, while VWFA connectivity with dorsal fronto-parietal attention network predicted visuo-spatial attention, but not language abilities. Our findings support a multiplex model of VWFA function characterized by distinct circuits for integrating language and attention, and point to connectivity-constrained cognition as a key principle of human brain organization.

Fig. 1. Participant selection and analysis pipelines.

a Key steps in selection of right-handed participants from the original HCP sample (N = 1206) to achieve a final sample size of N = 313; and b Data analysis pipeline for computing structural and functional connectivity measures and examining brain-behavior relationships (Exemplar image of picture vocabulary was adapted from Pichette et al.).

Fig. 2. Structural connectivity patterns of VWFA.

a Thresholded map showing probabilistic tractography of VWFA seed (p < 10⁻¹⁵) in the whole sample (N = 313). The location of VWFA is shown as a purple sphere on a map of the white-matter tracts originating from VWFA for a representational subject. All tracts terminate ventrally in the VWFA. b Averaged beta values within targeted ROIs in the language network (IFG, inferior frontal gyrus; SMG, supramarginal gyrus; AG, angular gyrus; ITG, inferior temporal gyrus) selected from Vogel et al.. c Averaged beta values within anterior, middle, and posterior sections of superior temporal sulcus (STS) selected based on 427 studies from NeuroSynth with the key word “reading”; d Attention-related networks (FEF, frontal eye field; aIPS and pIPS, anterior and posterior inferior parietal sulcus; MT+, V5/middle temporal visual area) selected from Vogel et al.. e Averaged beta values within the retinotopic ROIs within IPS1-4 identified in Swisher et al.. Error bars in the graph represent the standard error of means. Red dots on each bar represent individual data points.

Fig. 3. Intrinsic functional connectivity of VWFA.

a Thresholded map showing intrinsic functional connectivity of VWFA seed (p < 10⁻⁴⁰) in the whole sample (N = 313). b Averaged beta values within targeted ROIs in the language network (IFG, SMG, AG, and ITG) selected from Vogel et al.. c Averaged beta values within anterior, middle, and posterior sections of STS selected based on 427 studies from NeuroSynth with the key word “reading”. d Attention-related networks (FEF, aIPS, pIPS, and MT+) selected from Vogel et al.. e Averaged beta values within the retinotopic ROIs within IPS (IPS1-4) identified in Swisher et al.. Error bars in the graph represent the standard error of means. Red dots on each bar represent individual data points.

Fig. 4. VWFA circuits differentially predict language and visuo-spatial attention abilities across individuals.

a Structural connectivity of VWFA with STS nodes (anterior, middle, and posterior STS) was significantly correlated with individuals’ performance on picture vocabulary and word reading tasks, but not on the Flanker visuo-spatial attention task. b Structural connectivity of VWFA with fronto-parietal attention network nodes (FEF, aIPS, pIPS, and MT+) was significantly correlated with individuals’ performance on the Flanker attention task but not on the word reading or picture vocabulary tasks. Y-axis is age-adjusted performance scores on cognitive tasks and x-axis presents the predicted performance scores on cognitive tasks from the probability of structural connectivity of VWFA to either the language or the attention network ROIs.