The ITS ROI was defined in terms of a negative correlation

between spelling-sound consistency and BOLD signal in these participants. Evidence has been cited above for a role of the pMTG in phonological processing (Brambati et al., 2009, Indefrey and Levelt, 2004 and Richlan et al., 2009). It is, however, unlikely to be a phonology-specific processing area. In our study, this ROI was defined on the basis of a negative correlation PLX3397 in vivo with bigram frequency, which is a property of the orthographic input. In fact, pMTG activation was unrelated to biphone frequency (Graves et al., 2010). Unlike biphone frequency, bigram frequency is necessarily correlated with the frequency with which orthographic combinations are mapped to phonology. The orthography → phonology mapping is less practiced for words

with lower bigram frequency, resulting in less efficient orthography → phonology mapping for such words. The pMTG may therefore play a role in orthography → phonology mapping, perhaps as an intermediate representation linking orthographic and phonological codes, analogous to the “hidden unit” representations in triangle models. These models were implemented with pools of units dedicated to different codes (e.g., orthography, phonology, semantics). Because of their computational complexity, the mappings between codes are hypothesized to occur via interlevel units whose characteristics are determined by both input (e.g., orthography) and output (e.g., phonology) codes. The orthographic, phonological, www.selleckchem.com/products/AZD2281(Olaparib).html and semantic components are themselves assumed to develop from an initial state based on learning from perceptual-motor experience, and to be shaped by their participation in multiple computations (see Seidenberg, 2012 for discussion). It should be noted that various areas referred to as pMTG have also been implicated in studies of ZD1839 in vitro semantic processing (e.g., Binder et al., 2005, Binder et al., 2003, Noppeney and

Price, 2004, Pexman et al., 2007, Souza et al., 2009 and Whitney et al., 2011). How can this be reconciled with our interpretation of the pMTG as a component of the orthography → phonology mapping system? One possibility is that a single pMTG site supports both semantic processing and orth–phon mapping. However, the areas referred to as pMTG and linked with semantic processing in these studies may be spatially distinct from the pMTG area that we propose as a part of the orthography → phonology mapping. As suggested by the specificity of the correlations of pathway volume with imageability shown in Fig. 2 (only 2 of the 10 correlations tested were reliable), whether or not such correlations were detected depends a great deal on the morphology and exact location of the ROIs. The pMTG label, however, is both inherently imprecise and not always applied consistently across studies.