2006 Fiscal Year Final Research Report Summary
Brain mechanism on the binaural hearing and auditory-visual interaction assessed by the auditory evoked magnetic fields as well as conventional psychophysical methods
| Project/Area Number |
16390483
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Tohoku University |
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Principal Investigator |
KAWASE Tetsuaki Tohoku University, Graduate School of Medicine, Associate Professor, 大学院医学系研究科, 助教授 (50169728)
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| Co-Investigator(Kenkyū-buntansha) |
SUZUKI Yoiti Tohoku University, Research institute of electrical communiation, Professor, 教授 (20143034)
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| Project Period (FY) |
2004 – 2006
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| Keywords | magnetoencephalography / Masking level difference / Time-intrensity trading / functional hearing loss |
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| Research Abstract |
1.Binaural loudness summation: The well-known binaural effects of loudness summation, which is observed as a psychophysical phenomenon could not be verified by the N100m measurements. Although the loudness sensation considered to be related to the summed excitation level of auditory nerves, the summed potential from the auditory cortex (as N100m) might not necessarily reflect the loudness sensation.
2.Signal detection in background noise : Binaural unmasking refers to the improvement in intelligibility under conditions of masking when a tone is presented out of phase rather than in phase. Psychophysical binaural unmasking can be quantitatively evaluated by magnetoencephalography (MEG) in the auditory cortex level of the bilateral hemispheres in normal healthy subjects as well as in patients with the disturbance of consciousness.
3.Time-intensity trading : Time-intensity trading, which is related to the binaural ability to localize the sound, was observed under the normal condition as well as under the simulated condition of unilateral hearing disturbance. The unilateral disturbance appears to affect the time-intensity trading.
4.Effect of visual input on the N100m of the auditory evoked magnetic field : Although the effects of visual input on the N100m of the auditory evoked magnetic field was observed in the present study, basically no positive effects could not been obtained.
5.Neuromagnetic evidence of abnormal auditory function in children diagnosed as "functional hearing loss" : Functional hearing loss (FHL) is defined as the hearing disturbance for which there is no organic basis. In the present study, the cortical responses in patients with FHL diagnosed based on the conventional otological examinations was examined. The results suggest that some FHL patients have abnormal function at the level of auditory cortex that can be objectively evaluated by AEFs.
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Research Products
(4 results)
