| Authors | Braze, D., Mencl, W.E. Tabor, W., Pugh, K.R., Constable, R.T., Fulbright, R.K., Magnuson, J.S., Van Dyke, J.A., & Shankweiler, D.P. |
| Abstract | We present new evidence based on fMRI for the existence and neural architecture of an
abstract supramodal language system that can integrate linguistic inputs arising from
different modalities such that speech and print each activate a common code. Working with
sentence material, our aim was to find out where the putative supramodal system is located
and how it responds to comprehension challenges. To probe these questions we examined
BOLD activity in experienced readers while they performed a semantic categorization task
with matched written or spoken sentences that were either well-formed or contained
anomalies of syntactic form or pragmatic content. On whole-brain scans, both anomalies
increased net activity over non-anomalous baseline sentences, chiefly at left frontal and
temporal regions of heteromodal cortex. The anomaly-sensitive sites correspond approximately
to those that previous studies (Michael et al., 2001; Constable et al., 2004) have found to
be sensitive to other differences in sentence complexity (object relative minus subject relative).
Regions of interest (ROIs) were defined by peak response to anomaly averaging over modality
conditions. Each anomaly-sensitive ROI showed the same pattern of response across sentence
types in each modality. Voxel-by-voxel exploration over the whole brain based on a cosine
similarity measure of common function confirmed the specificity of supramodal zones. |