Where (in the brain) do semantic errors come from?
BACKGROUND
Semantic errors result from the disruption of access either to semantics or to lexical representations. One way to determine the origins of these errors is to evaluate comprehension of words that elicit semantic errors in naming. We hypothesized that in acute stroke there are different brain regions where dysfunction results in semantic errors in both naming and comprehension versus those with semantic errors in oral naming alone.


METHODS
A consecutive series of 196 patients with acute left hemispheric stroke who met inclusion criteria were evaluated with oral naming and spoken word/picture verification tasks and magnetic resonance imaging within 48 h of stroke onset. We evaluated the relationship between tissue dysfunction in 10 pre-specified Brodmann's areas (BA) and the production of coordinate semantic errors resulting from (1) semantic deficits or (2) lexical access deficits.


RESULTS
Semantic errors arising from semantic deficits were most associated with tissue dysfunction/infarct of left BA 22. Semantic errors resulting from lexical access deficits were associated with hypoperfusion/infarct of left BA 37.


CONCLUSIONS
Our study shows that semantic errors arising from damage to distinct cognitive processes reflect dysfunction of different brain regions.
Cloutman
Lauren
L
Department of Neurology, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA.
Gottesman
Rebecca
R
Chaudhry
Priyanka
P
Davis
Cameron
C
Kleinman
Jonathan T
JT
Pawlak
Mikolaj
M
Herskovits
Edward H
EH
Kannan
Vijay
V
Lee
Andrew
A
Newhart
Melissa
M
Heidler-Gary
Jennifer
J
Hillis
Argye E
AE
D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping; D016022:Case-Control Studies; D032882:Comprehension; D003210:Concept Formation; D007839:Functional Laterality; D006801:Humans; D007806:Language Disorders / Q000209:etiology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012016:Reference Values; D012660:Semantics; D020521:Stroke / Q000150:complications / Q000503:physiopathology*; D013702:Temporal Lobe / Q000502:physiology* / Q000503:physiopathology