Changes in hemoglobin concentration in the lateral occipital regions during shape recognition: a near-infrared spectroscopy study.
By using near-infrared spectroscopy (NIRS), we measured the changes in the oxygenated and deoxygenated hemoglobin (oxy-Hb and deoxy-Hb, respectively) concentrations while performing visual tasks. We conducted experiments using two tasks: a shape recognition task and a position recognition task. It was found that the oxy-Hb concentration was substantially higher in the lateral occipital regions during shape recognition than during position recognition. The changes in the oxy-Hb concentration were considered to reflect the activation difference between the two tasks. No difference was observed in the oxy-Hb concentration during the memorization of shape and memorization of position. The deoxy-Hb concentration was different between the two tasks only when different stimuli were used but not when identical stimuli were used. In addition, it was suggested that the deoxy-Hb concentration is more sensitive to activation difference between the hemispheres and the activation at some regions. Measurements of the oxy-Hb and deoxy-Hb concentrations would reflect different aspects of cortical activations. The present results showed that measuring the oxy-Hb and deoxy-Hb concentrations separately can differentiate the activation of the regional cortical functions.
Maehara
Goro
G
Kanazawa University, Department of Psychology, Kakuma, Kanazawa 920-1192, Japan. goro.maehara@mail.mcgill.ca
Taya
Shuichiro
S
Kojima
Haruyuki
H
D000328:Adult; D001921:Brain / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D010108:Oxyhemoglobins / Q000378:metabolism; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin