多模態情境之意圖結合效應

Abstract

意圖結合（Intentional binding, IB）效應指的是自主行為與其感官結果之間主觀時間的壓縮。大多數過往研究探討的是單模態感官結果的結合，例如聽覺、視覺或觸覺事件，本研究則探討多模態（視聽）感官結果的意圖結合。我們使用修改版的Libet Clock作為工具測量對於感官結果的主觀時間，同時呈現涉及聽覺和視覺模態的動態物理事件（碰撞）。實驗一檢驗了單模態（聽覺）事件的IB是否可以推廣至多模態（視聽）事件，並比較其幅度，同時檢驗模態間的整合程度是否會影響IB。實驗採用了2 x 3的重複測量設計：行動（被動/自主）和事件（聽覺/視聽整合/視聽無關）。事前比較（n = 42）顯示，對於所有類型的事件，都有顯著的IB效果；與聽覺相比，視聽整合和視聽無關情境下的IB效果顯著較弱，整合和無關情境之間則沒有差異。實驗二分離了視聽事件的組成部分，以檢驗適合描述多模態情境中IB效果的模型。第一個假設認為，視聽事件中的IB反映了聽覺和視覺模態之間IB的平均值；第二個假設認為視聽事件中的IB效果由視覺資訊決定（視覺優勢效果）；而第三個假設則認為視聽事件中較弱的IB是由於跨模態衰減所致。設計與實驗一相同，但視聽無關情境被視覺情境取代：事件（聽覺/視聽/視覺）。事前比較（n = 42）顯示，對於所有類型的事件，都有顯著的IB效果；與聽覺相比，視聽和視覺情境下的IB效果顯著較弱，而視聽和視覺情境之間沒有差異。因此，結果支持第二個假設。本研究揭示了意圖結合效應可以推廣至多模態（視聽）之感官結果，並且該效應在視聽模態下展現了視覺優勢效果。

Intentional binding (IB) refers to the compression of subjective timing between a voluntary action and its outcome. Most studies on this phenomenon have investigated the binding of unimodal sensory outcomes, such as auditory, visual, or tactile events. In this study, we investigate the IB of a multimodal (audiovisual) outcome. We used a modified Libet Clock to probe the subjective timing of the sensory outcome while depicting a dynamic physical event (collision) that involves both auditory and visual modalities. Experiment 1 examined whether IB for the unimodal (auditory) event could be generalized to the multimodal (audiovisual) event, compared their magnitudes, and assessed whether the level of integration between modalities could affect IB. It employed a 2 x 3 repeated measures design: Action (Passive/Agency) and Event (Auditory/Audiovisual Integrated/Audiovisual Irrelevant). Planned contrasts (n = 42) showed significant IB effects for all types of events; the magnitude of IB was significantly weaker in both Audiovisual Integrated and Audiovisual Irrelevant conditions compared to Auditory, with no difference between the Integrated and Irrelevant conditions. Experiment 2 separated the components of the audiovisual event to test the appropriate model describing the magnitude of IB in multimodal contexts. The first hypothesis posited that IB in audiovisual events reflects an average of IB between auditory and visual modalities; the second hypothesis suggested that the magnitude of IB in audiovisual events is determined by visual information; the third hypothesis suggested that weaker IB in audiovisual events was due to cross-modal attenuation. The design was identical to Experiment 1, except that the Audiovisual Irrelevant condition was replaced with a Visual condition: Event (Auditory/Audiovisual/Visual). Planned contrasts (n = 42) showed significant IB effects for all types of Events; the magnitude of IB was significantly weaker in both Audiovisual and Visual conditions compared to Auditory, with no difference between the Audiovisual and Visual conditions. Therefore, the results favored the second hypothesis. In conclusion, this study demonstrated that the IB phenomenon can be generalized to multimodal (audiovisual) sensory outcomes, and visual information shows dominance in determining the magnitude of IB in the audiovisual event.