Sentence complexity and input modality effects in sentence comprehension: an fMRI study.
Cortical regions engaged by sentence processing were mapped using functional MRI. The influence of input modality (spoken word vs. print input) and parsing difficulty (sentences containing subject-relative vs. object-relative clauses) was assessed. Auditory presentation was associated with pronounced activity at primary auditory cortex and across the superior temporal gyrus bilaterally. Printed sentences by contrast evoked major activity at several posterior sites in the left hemisphere, including the angular gyrus, supramarginal gyrus, and the fusiform gyrus in the occipitotemporal region. In addition, modality-independent regions were isolated, with greatest overlap seen in the inferior frontal gyrus (IFG). With respect to sentence complexity, object-relative sentences evoked heightened responses in comparison to subject-relative sentences at several left hemisphere sites, including IFG, the middle/superior temporal gyrus, and the angular gyrus. These sites showing modulation of activity as a function of sentence type, independent of input mode, arguably form the core of a cortical system essential to sentence parsing.
Constable
R Todd
RT
Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT 06520-8042, USA. todd.constable@yale.edu
Pugh
Kenneth R
KR
Berroya
Ella
E
Mencl
W Einar
WE
Westerveld
Michael
M
Ni
Weijia
W
Shankweiler
Donald
D
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D011578:Psycholinguistics; D011932:Reading; D013067:Speech Perception / Q000502:physiology*