Presentation
Search Abstracts | Symposia | Slide Sessions | Poster Sessions | Lightning Talks
Interacting effects of visual features and linguistic processing in the visual word form area
There is a Poster PDF for this presentation, but you must be a current member or registered to attend SNL 2023 to view it. Please go to your Account Home page to register.
Poster A121 in Poster Session A, Tuesday, October 24, 10:15 am - 12:00 pm CEST, Espace Vieux-Port
Vassiki Chauhan1, Krystal McCook1, Alex White1; 1Barnard College, Columbia University
The ability to read depends on a region in ventral temporal cortex known as the “visual word form area” (VWFA). Although it responds most strongly to written words, its selectivity is not absolute, and it exhibits top-down modulations related to task demands. Here, we used fMRI to characterize the factors that may boost activity in the VWFA: simply viewing words, attending to the visual properties of words, or explicitly engaging in a linguistic task. Participants viewed three types of character strings: familiar English words, unfamiliar pseudowords, and unfamiliar false fonts with visual properties matched to the words. We presented these stimuli in randomized sequences while participants performed three different tasks: discriminating the lexicality of the character string (word vs. nonword), discriminating the color of the character string, and discriminating the color of the fixation mark. If attending to any character string is sufficient to activate the VWFA, its responses should be elevated in the color task compared to the fixation task, for all stimulus types. If voluntary linguistic processing is necessary and sufficient to engage the VWFA, then for all stimulus types, activity should be highest in the lexical task. Contrary to both of these predictions, we found a strong interaction between stimulus type and task: compared to responses in the fixation color task, the VWFA’s response to text was elevated in the lexical task, but not in the character string color task. This result stands in contrast to predictions based on the automaticity of word recognition. Moreover, the VWFA’s response to false fonts was suppressed in the lexical task compared to the fixation task. Sensitivity to lexicality was also task-dependent: we found a higher response to pseudowords compared to real words during the lexical decision task, but not the color task. These patterns were absent in other nearby category-selective regions, such as the fusiform face area, but were present in a putative Broca’s area in left precentral sulcus. Additionally, we found high functional correlations between the Broca’s area and the VWFA only during the lexical decision task. In sum, activation of the VWFA is not merely dependent on the presence of words nor on engagement in a lexical task, but on the conjunction of both. These results highlight how the exquisite specialization of the ventral temporal cortex involves top-down feedback that is distinct from general forms of attention.
Topic Areas: Reading, Control, Selection, and Executive Processes