Abstract: | 在聽覺上偵測移動的物體,不論是對動物的生存或是人類的導航與社交能力而言都相當重要。本實驗探討人類的聽覺系統對於移動聲音的偵測能力,以及其如何在腦神經層面上對3D空間中音源移動的速率進行編碼。行為實驗一探討不同速率及角度的音源對聽覺運動物體的偵測能力造成的影響。在實驗二則利用功能性磁振造影儀器探討對於音源移動速率的神經編碼情況。行為實驗結果顯示,無論聲源速率為何,當聲源的位置在靠近中分面位置的區域時,其運動情況能被偵測的最好。而在速率60, 90, 180度/秒的情況中發現左右區域偵測效率不對稱的特徵。功能性磁振造影的結果顯示了不同的活化徵狀,快速運動與慢速運動的對比顯示在統計上顯著的腦活化程度差異,其位置位於右側的上顳葉(superior temporal)腦區。實驗結果說明當人類在偵測運動中的物體時,針對不同速率的音源可以找到對應的腦活化區域。Detection of auditory motion is important for animal survival as well as environmental navigation and human social interactions. In this study, we investigate the ability of human auditory system to detect the velocity of sound motion as well as the neural correlates in encoding the velocity of sounds presented in 3D space. In Experiment 1, the effect of velocities and azimuth angle on sound motion detection was studied. In Experiment 2, the neural correlates that encode the velocity of auditory sound motion were investigated using fMRI paradigm. Behavioral results showed that auditory motion was detected better at all velocities in the central azimuth area, and there were asymmetric patterns when motion velocity was at 60, 90, and 180 deg/s (degrees per second). Brain imaging data comparing fast motion with slow motion revealed significant activation differences in right superior temporal brain area. These data suggests that there might be distinct brain regions that selectively encode the velocity of a moving sound. |