Active versus passive listening to auditory streaming stimuli: a near-infrared spectroscopy study.
We use near-infrared spectroscopy (NIRS) to assess listeners' cortical responses to a 10-s series of pure tones separated in frequency. Listeners are instructed to either judge the rhythm of these "streaming" stimuli (active-response listening) or to listen to the stimuli passively. Experiment 1 shows that active-response listening causes increases in oxygenated hemoglobin (oxy-Hb) in response to all stimuli, generally over the (pre)motor cortices. The oxy-Hb increases are significantly larger over the right hemisphere than over the left for the final 5 s of the stimulus. Hemodynamic levels do not vary with changes in the frequency separation between the tones and corresponding changes in perceived rhythm ("gallop," "streaming," or "ambiguous"). Experiment 2 shows that hemodynamic levels are strongly influenced by listening mode. For the majority of time windows, active-response listening causes significantly larger oxy-Hb increases than passive listening, significantly over the left hemisphere during the stimulus and over both hemispheres after the stimulus. This difference cannot be attributed to physical motor activity and preparation related to button pressing after stimulus end, because this is required in both listening modes.
Remijn
Gerard B
GB
Kanazawa University, Graduate School of Medical Science, Department of Psychiatry and Neurobiology, Takara-machi 13-1, Kanazawa 920-8641, Japan. remijn@design.kyushuu.ac.jp
Kojima
Haruyuki
H
D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D002540:Cerebral Cortex / Q000098:blood supply / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D010108:Oxyhemoglobins / Q000737:chemistry; D011601:Psychophysics; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013997:Time Factors
D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin