title: Reduced frontal functional asymmetry in schizophrenia during a cued continuous performance test assessed with near-infrared spectroscopy.
abstract: Near-infrared spectroscopy (NIRS) allows noninvasive, in vivo measurement of changes in the concentrations of oxygenated hemoglobin (O2Hb) and deoxygenated hemoglobin (HHb) in brain tissue based on their distinctive optical properties. A previous NIRS investigation on healthy subjects (Fallgatter and Strik 1997) found indications of right frontal activation during a Continuous Performance Test (CPT) that are consistent with results from positron emission tomography (PET) and event-related potentials studies. The indications consisted of right frontal blood oxygenation changes, consistent with a hemodynamic response, along with a significant left frontal increase in HHb. The current study investigated whether this characteristic lateralized frontal NIRS activation pattern was present in a group of nine schizophrenia patients during the execution of a CPT. In contrast to the previous study, no overall or hemispheric activation effects were found in the schizophrenia subjects. Direct comparison of the results of the two studies confirmed group differences, with a lack of lateralized activation in schizophrenia patients. Furthermore, a trend of higher left/right HHb ratios at rest and during activation was found in patients with schizophrenia. The finding is interpreted as a sign of reduced specific lateralized frontal reactivity, possibly based on a left hemisphere functional deficit.
authors.affiliation: Dept of Psychiatry, University Hospital Wuerzburg, Germany. afallgat@mail.uni-wuerzburg.de
authors.forename: A J
authors.initials: AJ
authors.lastname: Fallgatter
authors.forename: W K
authors.initials: WK
authors.lastname: Strik
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003463:Cues; D004292:Dominance, Cerebral; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010108:Oxyhemoglobins / Q000378:metabolism; D011597:Psychomotor Performance; D012559:Schizophrenia / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared
chemical_list: D010108:Oxyhemoglobins