Evelina FEDORENKO (MIT)
What cognitive and neural mechanisms do we use to understand language? Since Broca's and Wernicke's seminal discoveries in the 19th century, a broad array of brain regions have been implicated in linguistic processing spanning frontal, temporal and parietal lobes, both hemispheres, and subcortical and cerebellar structures. However, characterizing the precise contribution of these different structures to linguistic processing has proven challenging. In this talk I will argue that high-level linguistic processing - including understanding individual word meanings and combining them into more complex structures/meanings - is accomplished by the joint engagement of two functionally and computationally distinct brain systems. The first is comprised of the classic “language regions” on the lateral surfaces of left frontal and temporal lobes that appear to be functionally specialized for linguistic processing (e.g., Fedorenko et al., 2011; Monti et al., 2009, 2012). And the second is the fronto-parietal ""multiple demand"" network, a set of regions that are engaged across a wide range of cognitive demands (e.g., Duncan, 2001, 2010). Most past neuroimaging work on language processing has not explicitly distinguished between these two systems, especially in the frontal lobes, where subsets of each system reside side by side within the region referred to as “Broca’s area” (Fedorenko et al., in press). Using methods which surpass traditional neuroimaging methods in sensitivity and functional resolution (Fedorenko et al., 2010; Nieto-Castañon & Fedorenko, in press; Saxe et al., 2006), we are beginning to characterize the important roles played by both domain-specific and domain-general brain regions in linguistic processing.