Hyperoxia-enhanced activation-induced hemodynamic response in human VI: anfMRI study

The effect hyperoxia had on the hemodynamic response to visual stimulation (black and white checkerboard alternating at a frequency of 8 Hz) of human VI was investigated using a blood oxygenation level-dependent (BOLD) contra st with an fMRI technique. Data were acquired with a 5 on/5 off block parad igm using single-shot gradient-echo echo-planar imaging. Using a two-tailed paired t-test (P<0.05, n = 13) It was found that the mean percentage signa l change and the mean number of activated pixels was significantly increase d for hyperoxia (5.7 +/- 0.9, 187 +/- 73 mean +/- SD) relative to those for normoxia (5.4 +/- 0.9, 168 +/- 58). We believe that these results indicate that hyperoxia enhances the activation-induced hemodynamic response in hum an VI. NeuroReport 11:903-906 (C) 2000 Lippincott Williams & Wilkins.