Brain activation pattern during a verbal fluency task in depression patients: a near-infrared spectroscopy imaging study

Objective To investigate the difference of brain activation patterns between depression patients and normal persons by near-infrared spectroscopy imaging. Methods Totally 14 depressed patients and 13 sex, age, and education matched healthy controls were required to perform category verbal fluency task (VFT). The relative concentration of deoxygenate hemoglobin and oxygenate hemoglobin was collected by a 45-channel instrument, and the data was processed with the software of Statistical Parametric Mapping (SPM). Results The task performances were not significantly different between the two groups, the average curve of oxygenate hemoglobin and deoxygenate hemoglobin were lower in depressed patients with significant difference in dorsolateral prefrontal cortex.For instance, the oxygenate change in Channel 38 and Channel 41 was Deoxy-Hb（t=3.29,3.47）, Oxy-Hb（t=3.18，4.03）,P<0.10. Conclusion The activation in bilateral dorsolateral prefrontal cortex may be lower in depression patients compared to control group. Key words: Depressive disorder; Prefrontal cortex; Spectroscopy，near-infrared; Verbal fluency task; Statistical parametric mapping