passages.id: split_4_test_131_passage
passages.type: progene_text
passages.text: The spectral changes of absorbance indicated that the concentrations of both total hemoglobin and oxyhemoglobin increased together with rCBF ; deoxyhemoglobin , increased slightly but distinctly ( P = 0.016 at 1.0 seconds , P = 0.00038 at 1.5 seconds ) just before rCBF increases , then decreased .