title: Differential prefrontal and frontotemporal oxygenation patterns during phonemic and semantic verbal fluency.
abstract: Movement artifacts are still considered a problematic issue for imaging research on overt language production. This motion-sensitivity can be overcome by functional near-infrared spectroscopy (fNIRS). In the present study, 50 healthy subjects performed a combined phonemic and semantic overt verbal fluency task while frontal and temporal cortex oxygenation was recorded using multi-channel fNIRS. Results showed a partial dissociation for phonemic and semantic word generation with equally increased oxygenation in frontotemporal cortices for both types of tasks whereas anterior and superior prefrontal areas were exclusively activated during phonemic fluency. Also, a general left-lateralization was found being more pronounced during semantic processing. These findings line up with earlier imaging and lesion studies emphasizing a crucial role of the temporal lobe for semantic word production, whereas phonemic processing seems to depend on intact frontal lobe function.
authors.affiliation: University Hospital Wuerzburg, Department of Psychiatry, Psychosomatics and Psychotherapy, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany. Tupak S@klinik.uni-wuerzburg.de
authors.forename: Sara V
authors.initials: SV
authors.lastname: Tupak
authors.forename: Meike
authors.initials: M
authors.lastname: Badewien
authors.forename: Thomas
authors.initials: T
authors.lastname: Dresler
authors.forename: Tim
authors.initials: T
authors.lastname: Hahn
authors.forename: Lena H
authors.initials: LH
authors.lastname: Ernst
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Herrmann
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Ehlis
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007807:Language Tests; D008297:Male; D010108:Oxyhemoglobins / Q000378:metabolism*; D010700:Phonetics; D017397:Prefrontal Cortex / Q000378:metabolism*; D012660:Semantics; D019265:Spectroscopy, Near-Infrared; D013702:Temporal Lobe / Q000378:metabolism*; D014705:Verbal Behavior; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins