Investigation of neuropsychological processes in music perception using magnetoencephalography.

我们的研究是在以下四个主要主题下进行的，并简要说明了结果。（1）听觉后向掩蔽和脑磁图听觉掩蔽被认为通过频率选择性和时间分辨力对音乐知觉有重要影响。此外，近年来发现后掩蔽效应的大小与儿童语言能力的发展有关，这使得后掩蔽效应的研究显得尤为重要。我们研究了脑磁图反应的刺激引起后掩蔽。结果表明，例如，N1 m峰值振幅表现出信号和掩蔽的内部响应之间的一些非线性关系。我们正在构建一个模型，这种现象利用时间窗口提出的行为结果的后向掩蔽实验。（2）对不协和和弦的脑磁图反应我们特别发现，对于两个小二度音程的纯音，诱发磁场在其起始后约200-400 ms出现高频成分（20- 40 Hz）叠加在直流成分上。我们正在寻找信号源，这些组件使用许多科目。我们还注意到，这种较长的潜伏期组件与诱发的磁场40赫兹调制啁啾或纯音之间的相似性。（3）旋律知觉、工作记忆和脑磁图反应我们准备了几个由三个音符组成的短语，并以类似于调查工作记忆的实验的方式将它们呈现给受试者。诱发的磁场与被试记忆任务的难度有关。（4）MEG 40 Hz分量中的相位同步本实验与上述（2）相关。我们测量了受试者听到250-500 Hz音调调制40 /s时40 Hz分量相位的同步性。已经提出了一个描述相的动力学模型。

Our research has been done under the four main topics given below with brief descriptbion of the results.(1)Auditory backward masking and MEG Auditory masking is considered to have significant bearing on musical perception through frequency selectivity and time resolution. Furthermore, it has been recently found out that the amount of backward masking is related to the development of language ability of children, which makes its research all the more important. We investigated MEG responses to stimuli causing backward masking. The results show for example that the N1m peak amplitudes demonstrate some nonlinear relationship between the internal responses to signal and to masker. We are constructing a model for this phenomenon utilizing the time window proposed for behavioral results of backward masking experiments.(2)MEG responses to dissonant chords We found in particular, that for two pure tones with the minor second interval, evoked magnetic fields show higher frequency components (20-40Hz) superimposed on a DC component around 200-400 ms after the onset of the tones. We are looking for signal sources for these components using many subjects. We also note the similarity between this longer latency components with the evoked magnetic fields to 40-Hz modulated chirps or pure tones.(3)Melody perception, working memory and MEG responses We prepared several phrases composed of three notes and presented them to subjects in a similar manner to experiments for investigation of working memory. The evoked magnetic fields were related to the difficulty in memory tasks imposed on the subjects.(4)Phase synchronization in the MEG 40 Hz component This experiment is related to (2)as described. We measured the synchronization of the phases of 40 Hz component when the subject hears 250-500 Hz tone modulated 40 /s. A model describing the dynamics of the phase has been proposed.