Poster E57, Saturday, August 18, 3:00 – 4:45 pm, Room 2000AB
Learning to Read a Second Orthography Recruits the Visual Word Form Area and a Broader Reading Network
Lea Martin1,2, Corrine Durisko1,3, Michelle W. Moore4, Julie A. Fiez1,2,3;1University of Pittsburgh, PA, 2Center for the Neural Basis of Cognition, University of Pittsburgh, PA, 3Learning Research and Development Center, University of Pittsburgh, PA, 4West Virginia University, Morgantown, WV
Introduction: A region within the mid-fusiform gyrus, the visual word for area (VWFA), appears to support word recognition as an individual attains reading fluency. Questions remain about why this tissue specifically appears to facilitate fluent reading. Some theories posit that the VWFA responds to orthographic information because most orthographies share similar visual characteristics (e.g., line junctions). Other theories suggest the VWFA functions as a bridge between visual recognition regions and spoken language regions. In an effort to test these competing theories and to better characterize the role played by different mapping principles across orthographies, we created and examined four artificial orthographies across several studies to investigate behavioral and neural measures of learning in adult participants who acquired a second, visually distinct orthography for English. Methods: We collected behavioral and neuroimaging data from two groups of subjects trained for two weeks (initial training) to acquire basic reading proficiency in either KoreanFont or FaceFont, two alphabetic systems wherein English phonemes are represented by letters borrowed from the Hangul alphabet and face images, respectfully. In addition, two groups of subjects were followed for six weeks (initial training and four weeks of extended training) as they learned to read HouseFont, an alphabetic system wherein house images represent English phonemes, and Faceabary, an alphasyllabic system wherein face images represent English syllables. Participants underwent neuroimaging scans before and after training. Results: Participants were able to acquire basic reading proficiency from initial training. In the extended training for HouseFont and Faceabary participants improved in reading accuracy and reading speed, with no evidence of a learning plateau. Neuroimaging data acquired at the end of initial training indicated that there was an increase in activity for an individual’s trained font in the vicinity of the VWFA. Faceabary participants displayed increased activity in the right mid-fusiform after training, consistent with bilateral activation patterns seen in other alphasyllabic writing systems. Increased VWFA activity correlated with an increase in reading fluency. Neural changes within the broader reading network indicated that Faceabary, the alphasyllabic system, more strongly engaged the semantic reading network. Conclusion: Native English speaking adults maintain the ability to learn a second, visually distinct orthography for their native language, suggesting that the neural substrates underlying reading ability remain flexible even into adulthood and after initial literacy is established. While orthographic learning was associated with increased VWFA activation for all the orthographies we investigated, the differences in mapping principles between orthographies drove the specific utilization of the broader reading network. These patterns of response have several implications: 1) the VWFA retains flexibility with regard to the type of stimuli it can utilize as orthographically meaningful; 2) reading fluency in a newly learned orthography is associated with changes in the VWFA (both unilateral changes in alphabetic systems and bilateral changes in alphasyllabic systems); 3) differential recruitment of the broader reading network is dependent on the mapping principles, with semantic network recruitment occurring more strongly for alphasyllabic systems.
Topic Area: Multilingualism