A new empirical angle on the variability debate: Quantitative neurosyntactic analyses of a large data set from Broca's Aphasia

Dan Drai, Yosef Grodzinsky
2006 Brain and Language  
Behavioral variation in BrocaÕs aphasia has been characterized as boundless, calling into question the validity of the syndromebased schema and related diagnostic methods of acquired language disorders. More generally, this putative variability has cast serious doubts on the feasibility of localizing linguistic operations in cortex. We present a new approach to the quantitative analysis of deficient linguistic performance, and apply it to a large data set, constructed from the published
more » ... re: Comprehension data of 69 carefully selected BrocaÕs aphasic patients, tested on nearly 6000 stimulus sentences, were partitioned in different ways, and subjected to a series of analyses. While a certain amount of variability is indeed evident in the data, our quantitative analyses reveal a highly robust selective impairment pattern for the group: the patientsÕ ability to analyze syntactic movement is severely compromised, in line with the Trace-Deletion Hypothesis. Further analyses suggest that patientsÕ performance on no-movement sentence types exhibits less variation than on sentences that contain movement. We discuss the clinical and theoretical implications of our results.
doi:10.1016/j.bandl.2004.10.016 pmid:16115671 fatcat:zys2quy3hvddzfvdnkxt4qrr6i