Charting the functional relevance of Broca's area for visual word recognition and picture naming in Dutch using fMRI-guided TMS.
Magnetoencephalography (MEG) has shown pseudohomophone priming effects at Broca's area (specifically pars opercularis of left inferior frontal gyrus and precentral gyrus; LIFGpo/PCG) within ∼100ms of viewing a word. This is consistent with Broca's area involvement in fast phonological access during visual word recognition. Here we used online transcranial magnetic stimulation (TMS) to investigate whether LIFGpo/PCG is necessary for (not just correlated with) visual word recognition by ∼100ms. Pulses were delivered to individually fMRI-defined LIFGpo/PCG in Dutch speakers 75-500ms after stimulus onset during reading and picture naming. Reading and picture naming reactions times were significantly slower following pulses at 225-300ms. Contrary to predictions, there was no disruption to reading for pulses before 225ms. This does not provide evidence in favour of a functional role for LIFGpo/PCG in reading before 225ms in this case, but does extend previous findings in picture stimuli to written Dutch words.
Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, The Netherlands. Katie.Wheat@maastrichtuniversity.nl
Katherine L
KL
Wheat
Piers L
PL
Cornelissen
Alexander T
AT
Sack
Teresa
T
Schuhmann
Rainer
R
Goebel
Leo
L
Blomert
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D011930:Reaction Time; D011932:Reading; D013060:Speech / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult