Introduction: Abnormalities in the dynamic aspects of brain activity could underlie the pathophysiology of psychiatric disorders. Temporal characteristics of cerebral blood volume change, which are candidate indices of such dynamic aspects, were examined using a multichannel near-infrared spectroscopy (NIRS) machine. Methods: Thirty right-handed healthy volunteers participated in the study (mean age: 27.1+/-3.0, age range: 22-33; 15 males and 15 females). The relative concentrations of oxy-hemoglobin ([oxy-Hb]) were measured during a 40-s unilateral finger-tapping task using two sets of probes of the 24-channel NIRS machine placed on the subjects' temporal regions with a time resolution of 0.1 s. Grand averaged waveforms of [oxy-Hb] across all subjects were obtained from the individually averaged waveforms for each side of tapping in 24 channels. Results: Temporal characteristics of the [oxy-Hb] increase during the tapping period and were classified into three patterns: (1) slow and gradual increase during the task; (2) sustained increase across the task; and (3) initial peak in the early segment of the task. The channels showing the three patterns corresponded approximately to the primary motor, premotor and primary somatosensory areas, respectively. The extent of contralateral hemisphere activation of the tapping side was greater in the right-finger-tapping task than that found in the left-finger-tapping task. Conclusion: Temporal characteristics of cerebral blood volume change were noninvasively demonstrated to vary among various cortical areas using a multichannel NIRS machine.