藉由回饋關聯腦負波訊號衡量虛擬實境中的認知衝突

Abstract

隨著虛擬實境(Virtual Reality, VR)成為主流平台，設計師開始著手去研究新的互動方式以加強使用者身歷其境的感覺。這是一項具有挑戰性的任務，因為設計師不僅要提供好的軟硬體流暢度外，還需確保虛擬實境裡的運作方式不會與人類認知習性產生衝突，以達到更高的沉浸體驗。以往針對這類問題僅能依靠調查問卷和訪談進行評估，並不能深入探討人類在虛擬實境的認知運作，以及相關的大腦動態反映。因此， 本研究提出一個基於腦電波的研究框架，透過虛擬實境觸碰作業(VR Touching Task)，操弄碰觸方塊的感測距離，有意識地引發虛擬實境的認知衝突(預估與實際距離產生差異 ) ， 並 以 事 件 相 關 電 位 (Event-Related Potentials) 中 回 饋 關 聯 負 波 成 分 波 (Feedback- Related Negativity)作為大腦反應的評估。此外，本實驗也進一步操弄不同虛擬實境反應表徵(替代反應手樣式)以了解對此成分波的影響。實驗結果發現，回饋關聯負波的振福會受到虛擬反應表徵手的擬真程度以及人格特質的交互作用影響，這可能是因為在虛擬實境中，越擬真的手表徵會被當成自我身體的延伸，而更易以個人習慣方式進行應對。而越不擬真的手表徵則較易被當作使用工具或媒介(agency)，而較不受到個人特質所影響。本研究對人類在虛擬實境中的應對模式提供了更多的認識，其腦波評估方式將可提供虛擬實境設計師，做為設計成效的指標，改善替代表徵與人類真實經驗的吻合度以提供更流暢的沉浸體驗。

As virtual reality (VR) emerges as a mainstream platform, designers have started to experiment new interaction techniques to enhance the user immersive experience. This is a challenging task because designers not only strive to provide designs with good performance, but also carefully ensure not to disrupt users’ immersive experience. In the past, these problems can only rely mainly on questionnaires and interviews to assess, and cannot in-depth discussion of human cognitive operation in the virtual reality, as well as the relevant brain dynamic reflection. Therefore, the present study proposes an EEG-based experiment framework that by VR Touching Task, the sensing distance of touching cube is intentionally elicited by cognitive conflict in VR, which different between the estimated and the actual distance and the Feedback- Related Negativity of Event-Related Potentials (ERP) can evaluate the brain reaction. In addition, the experiment also further manipulates the different VR representation (the reaction of alternative hand style) to understand the effect of wave for this component. The experimental results show that the Feedback-Related Negativity (FRN) will be affected by the interaction between the realistic level of the virtual representation response and the individual predispositions. This may be that in the virtual reality, if the hand is more realistic and it will be as the extention of own body. Whereas, the users can be more easily to respond by personal habits. Then, if the hand is less realistic and it would be used as a tool or agency easily ,and have less effect by individual predispositions. This study provides more knowledge for the reaction mode of human in virtual reality. The Electroencephalography (EEG) as assessment method can supply VR designers which can also be the indicators of design effectiveness. Moreover, the indicator can improve the alternative representations with human experience in real world to furnish smoother immersive experience.