Schubert, T. & Rapp, B.
Department of Cognitive Science. Johns Hopkins University. Baltimore, USA.
Research has identified the role of the left mid-fusiform gyrus in reading (Cohen et al., 2002) and spelling (Rapp & Lipka, 2011). Furthermore, this region -often referred to as the VWFA (Visual Word Form Area) has been implicated in acquisition of literacy (Dehaene, et al. 2010) and also shows increased processing efficiency with increasing word frequency and with repeated presentations of written words (Pugh et al., 2008). The current study examined the involvement of the VWFA and the hippocampus in the real-time learning of orthographic representations by normal adults. During scanning, participants learned mappings between auditory pseudowords and orthographic forms. Whole-brain analysis revealed that the orthographic learning recruited the left mid-fusiform gyrus, left inferior gyrus, and left supramarginal gyrus. Learning trials were categorized both by presentation number (Pugh et al., 2008) and memory strength (Law et al., 2005) to investigate the time course of learning. Results revealed that activation in the functionally-defined VWFA decreased as both memory strength and number of repetitions increased. Conversely, activation in the bilateral hippocampus increased as a function of memory strength. These results provide novel evidence of the distinctive roles played by the VWFA and hippocampus in acquisition of orthographic representations.