節奏規律性對音高知覺判斷的影響

Abstract

動態注意力理論指出，注意力並非固定不變，當外在環境的刺激具有規律性的時間節奏時，注意力會以動態振盪的方式與規律的刺激序列同步化，形成具有內部規律性的注意力節奏，而此同步化還可形成預期性注意，致使人們將注意力轉移到刺激出現的時間點上進而預期下一個刺激出現的時間。過去的實驗證實了節奏的規律性能夠影響人們對於聲音出現的時間點的判斷，當外在刺激為規律的時間節奏時，如果後續聲音出現的時間點符合節奏的預期，則我們判斷該聲音出現的時間點的反應正確率及反應時間都會較好，支持了動態注意力理論。本研究欲進一步了解若外在的規律刺激能夠導致注意力與之同步，節奏規律性對於人們在音高的判斷是否也會有一樣的促進效果。因此本研究複製了Jones等人（2002）的實驗一，但根據Bauer等人（2015）的實驗五進行修改。受試者聆聽包含標準音、內插音、與比較音的聲音序列，需要根據標準音來判斷比較音的音高是相同、較高、或較低。本研究從最後一個內插音與比較音之間的刺激出現時間差（包含可預期與不可預期的刺激出現時間差)及實驗段（包含四個實驗段）去分析受試者的反應正確率及反應時間，發現受試者對於比較音出現在可預期與不可預期的時間點的反應正確率與反應時間沒有任何的顯著差異，實驗結果與Jones等人的實驗結果不符，顯示節奏規律性無法促進人們的音高知覺判斷。然而，本研究發現受試者判斷比較音高的反應正確率與反應時間會隨著反覆的循環施測而逐漸進步，顯示無論外在刺激是否規律，反覆訓練都可以促進人們在音高判斷作業上的表現。Dynamic attending theory proposes that attention is flexible. Attention can dynamically synchronize with the temporally regular stimulus sequence in the external environment. Such synchronization not only forms a stimulus-driven rhythm of attention but also creates anticipatory attention, entailing a temporal shift of attention that anticipates the onset time of a stimulus. Previous experiments have demonstrated that temporal regularity can improve participants’ judgment on when a sound appears. That is, participants’ response accuracy was higher and reaction time was lower when a sound appears at expected, relative to unexpected, time points. The purpose of this study was to furtherexamine whether temporal regularity would have the same effect on participants’ judgment of pitch. We adapted the Experiment 1 of Jones et al. (2002) according to the Experiment 5 of Bauer et al. (2015). Participants listened to a sequence of auditory stimuli including a standard tone, several interpolated tones, and a comparison tone. Participants were required to judge whether the pitch of the comparison tone was equal to, higher than, or lower than the pitch of the standard tone. We analyzed participants’ response accuracy and reaction time by stimulus onset asynchrony (SOA) between the last interpolated tone and the comparison tone (including very early, early, expected, late, and very late) and experimental blocks (including four blocks). We found that participants’ response accuracy and reaction time did not differ between conditions when the comparison tone appeared at the expected and unexpected time points. The result suggested that temporal regularity cannot facilitate pitch perception, inconsistent with the reports of Jones et al. We only found that participants’ response accuracy and reaction time gradually improved with experimental blocks, suggesting that practice can improve participants’ judgment of pitch.