, 2005, Friederici, 2009, Glasser and Rilling, 2008, Makris and Pandya, 2009, Saur et al., 2008 and Weiller et al., 2009). In particular, syntactic processing has been argued to depend on dorsal tracts (Friederici, 2009 and Friederici et al., 2006) as well as ventral tracts: the ECFS (Saur et al., 2008 and Weiller et al., 2009) or Birinapant in vivo the UF (Friederici,

2009 and Friederici et al., 2006). The aim of the current study was to identify which white matter tract(s) are important for syntactic processing, by examining the relationship between white matter damage and syntactic deficits in patients with primary progressive aphasia (PPA). This cohort presents a unique opportunity to identify associations between white matter damage and syntactic deficits, because patients with PPA vary considerably in terms of which white matter tracts are damaged (Agosta et al., 2010, Galantucci et al., 2011 and Whitwell et al., 2010), as well as in the extent to which syntax is impaired (Amici et al., 2007, Gorno-Tempini et al., 2004, Gorno-Tempini et al.,

2011, Grossman click here and Moore, 2005, Grossman et al., 2005, Hodges and Patterson, 1996, Thompson et al., 1997 and Wilson et al., 2010b). We used diffusion tensor imaging to examine the SLF/Arcuate, ECFS and UF in 27 patients with PPA. Syntactic comprehension was assessed using a two-alternative forced choice auditory sentence-to-picture matching task (Wilson et al., 2010a), syntactic production was assessed based on connected speech samples, and several other speech, language, and cognitive measures were obtained, including control (nonsyntactic) measures of single word processing. The integrity of each tract was quantified in terms of mean fractional anisotropy (FA) and related to the syntactic and other behavioral measures to determine Astemizole the functional roles of each tract. We defined the SLF/Arcuate (considered as a single tract), ECFS and UF by placing seed regions of interest

at known “bottlenecks” on individual patients’ color-coded diffusion maps (Figures 1A–1C). Each of the three tracts of interest was identified in all patients (Figures 1D–1G). The three tracts identified were broadly consistent with previous studies (e.g., Makris and Pandya, 2009 and Galantucci et al., 2011). Syntactic comprehension and production scores spanned a wide range, as expected given the spectrum of syntactic function in PPA. The mean comprehension score was 75.4% (SD = 13.1%, range = 50.0%–90.5%) and the mean production score (on a scale from 1 to 7) was 5.1 (SD = 1.7, range = 1.5–7.0). Syntactic comprehension and production scores were highly correlated (r = 0.79, p < 0.0001). This suggests that our syntactic assessments primarily captured core syntactic processes rather than related but peripheral processes such as executive functions or motor speech.