Functionally Localizing Language‐Sensitive Regions in Individual Subjects With fMRI: A Reply to Grodzinsky’s Critique of Fedorenko and Kanwisher (2009)

Abstract In Fedorenko and Kanwisher (F&K 2009), we argued that defining regions of interest functionally in individual subjects may lead to a clearer picture of the functional architecture of the language system because it affords higher sensitivity and selectivity. Grodzinsky (2010) takes issue with two aspects of the F&K paper. First, he argues that the picture of the neural basis of language that has emerged from previous work is not as murky as F&K argue, with the implication that perhaps a new method is not needed. And second, he raises some concerns with the individual‐subjects functional localization approach and argues instead for the use of probabilistic cytoarchitectonic maps (e.g., Amunts et al. 1999). In the current manuscript, we respond to both of Grodzinsky’s points. Regarding the first point, we stand by our assessment of the brain basis of language literature, and argue that many core questions related to functional specialization remain unanswered. We explain why we remain unconvinced by Grodzinsky’s example of Broca’s area (or a portion of it) as a region with a well‐understood functional profile. Regarding the concerns that Grodzinsky raises with respect to the use of functional localizers in investigating the language system, we respond to the main comments and refer the reader to Fedorenko et al. (2010) where the remaining concerns are addressed (with both data and argumentation). Finally, we point out that the probabilistic cytoarchitectonic maps that Grodzinsky advocates have some of the same limitations as other group‐based methods. We conclude that the individual‐subjects functional localization approach, advocated in F&K, holds promise for better understanding the brain basis of language by enabling a detailed characterization of language‐sensitive regions with respect to their role in both linguistic and non‐linguistic processes.