Abstract
The visual word form area (VWFA) is an experience-dependent region in left ventral temporal cortex (VTC) that responds to written words and letters. However, after more than three decades of investigation, the nature and even the existence of this region is still under debate. Some studies suggest that the VWFA is not dedicated to visual words/not distinct from other VTC regions; others argue that the VWFA is not even visual and is instead part of the amodal language and/or attention networks. Here, we scanned 54 adults on: visual localizers to delineate subject-specific VTC category-selective functional ROIs (fROIs); auditory language localizer to assess linguistic processing; and spatial working memory (SWM) task to assess attentional load-based responses. We found that only the VWFA shows significantly greater response to visual words compared to all other high-level visual stimuli, auditory language conditions, and SWM conditions. This was replicated across methods for defining the VWFA (i.e., identifying VWFA with different control conditions, selecting top 10% within a search space, and applying a significance threshold). Moreover, while the VWFA is unique within the VTC in showing word-selectivity, its selectivity to auditory language is on par with various other VTC fROIs and any language selectivity within the VTC is dwarfed by language selectivity of the canonical language network. Additionally, all VTC fROIs, except retrosplenial cortex , are modulated by attention on the SWM task. Overall, we used precision fMRI with multiple tasks to thoroughly examine the VWFA, finding that while it does show some linguistic and attentional sensitivities, it is clearly a visual region and distinct from adjacent VTC visual regions in its neural preferences for orthography; it is also distinct from canonical language or dorsal attention networks, caring more about visual aspects of words than higher-level linguistic content.