視聽知覺對自然與都市景觀壓力削減之影響

Abstract

根據許多先前的文獻指出，自然景觀對人類具有壓力削減的效果，且多數文獻關注視覺的體驗，鮮少其他知覺之研究。聽覺亦是人類重要之感官知覺，自然的聲音可以提供恢復性體驗在於它能生動的顯現我們所生存、重要的自然環境；且前人研究發現播放一個只有影像、沒有聲音的自然環境影片會讓人覺得過於安靜、不自在。過去雖有少數學者關注聽覺的體驗，但這些文獻多僅針對聽覺之單一知覺。然而，人類知覺是複合的感官體驗，而聯合視聽知覺佔人類感官體驗之比例高達94％。在景觀領域已有研究證實，聽覺自然度比視覺自然度更顯著的影響寧靜感，顯現視聽知覺對人類接受訊息與感知具有影響效果。早期Ulrich（1991）一篇比較都市與自然景觀之壓力削減的研究，即採用影音混合之影片做為刺激媒體，迄今引用率極高，堪稱自然景觀壓力削減之經典研究。但其實驗媒體是視聽混合的影片，沒有將兩種知覺分開測量，無法確切瞭解壓力削減之效果係分別來自視覺或聽覺，抑或是視聽混合之效益。因此本研究參考此篇經典的實驗設計，進一步探究視聽知覺對環境（自然與都市）壓力削減效果之影響。 參考過去研究壓力削減生心理相關之文獻常用之代表性場景，自然景觀實驗媒體多選用公園綠地、農地、山岳、海洋場景；都市景觀則多選用交通設施、商業大樓、街道建築。實驗媒體為5分鐘景觀影片，影像的部分來自Videvo、Pexels Videos影片素材網站和自行拍攝，聲音的部分利用Freesound聲音素材網站進行配音。受試者180位皆為來自都市的國立台灣大學在學學生（18~30歲），分為自然景觀影像組（Nv）、自然景觀聲音組（Na）、自然景觀影音組（Nva）、都市景觀影像組（Uv）、都市景觀聲音組（Ua）、都市景觀影音組（Uva）共6組實驗組，每一組包含30位受試者。生理指標利用生理回饋儀器蒐集並匯出α和β腦波（EEG）、末梢血液流量（BVP）、心跳變異率（HRV）及肌電值（EMG）之數據；心理指標則利用ZIPERS、ROS7級量表組成之自我評估問卷。生理實驗分為3個階段皆為5分鐘（共15分鐘），分別為閉眼放鬆、壓力刺激及壓力削減階段。第一階段（閉眼放鬆）蒐集生理基準值，第二階段（壓力刺激）進行快問快答遊戲提升受試者的壓力值，第三階段（壓力削減）隨機觀賞一組5分鐘的景觀影片，實驗結束後填寫自我評估問卷。 研究結果顯示，在自然景觀中，生理指標「β腦波」3種不同知覺刺激方式具顯著差異，聲音刺激下的自然景觀比影像或影音刺激獲得較少的壓力削減效果；心理指標「認知」3種不同知覺刺激方式具顯著差異，結果顯示影音刺激下的自然景觀比影像刺激更能忘記煩惱和釐清思緒。在都市景觀中，心理指標「恐懼/喚起」、「憤怒/侵犯」3種不同知覺刺激方式具顯著差異，結果顯示聲音刺激下的都市景觀比影像或影音刺激更使人處於負面情緒的狀態中。不同「知覺刺激」下的景觀體驗產生的壓力削減結果在「α腦波」、「β腦波」、「LF％」、「HF％」4項生理指標與「憤怒/侵犯」心理指標具有顯著差異；體驗不同「環境」產生的壓力削減結果在「恐懼/喚起」、「憤怒/侵犯」、「正向情緒」、「專注」、「放鬆」、「注意力恢復」、「認知」心理指標具有顯著差異；在「TP」生理指標與「憤怒/侵犯」心理指標中，不同「知覺刺激」下的不同「環境」體驗具有顯著的交互作用。

Anecdotal evidence demonstrated that experiences in natural scenes could reduce stress. Most literature focuses on the visual experience, with little research on other perceptions. Auditory perception is also an important sensory perception of human beings. The natural sound can provide a restorative experience in that it vividly reveals the natural environment in which we live and be important. Previous studies have found that playing a natural environment film with only images and no sound can make people feel too quiet and uncomfortable. Although a few scholars have paid attention to the experience of auditory perception, these documents are mostly directed at the single perception. However, human perception is a multisensory effect. Auditory and visual perception accounts for up to 94% of the sensory experience. Studies in the field of landscape have confirmed that auditory naturalness has more significant impact on tranquility than visual one. This shows that auditory and visual perceptions have an effect on human acceptance of information. Ulrich (1991) studied comparing the pressure reduction of urban and nature landscapes, using a mixture of audio and video as a stimulating medium, has so far been cited as a classic study of stress reduction in natural landscapes. However, the two perceptions are not measured separately. It is difficult to know exactly whether the effects of stress reduction are from visual or auditory or the mix. Therefore, this study refers to this classic experimental design to explore the impact of auditory and visual perceptions on the environmental (natural and urban) stress reduction. Referring to the scenes commonly used in the prior studies related to the stress reduction and psychophysical responses, natural landscape test media mostly used park, farms, mountains, and oceans. Urban landscapes mostly used transportation facilities, commercial buildings, and street buildings. The test media is a 5-minute landscape film. Video materials come from the website of Videvo, Pexels Videos, and shooting by myself. Sound materials come from the website of Freesound. 180 National Taiwan University student participants (aged 18-30) were divided into six groups based on the type of perception and two environments, including a video group (Nv), an audio group (Na), a group of video and audio (Nva) in natural landscape, and a video group (Uv), an audio group (Ua), a group of video and audio (Uva) in urban landscape. Their physiological responses were measured by α-wave and β-wave (EEG), blood volume pulse (BVP), heart rate variability (HRV), and electromyography (EMG). Psychological responses were measured by means of the ZIPERS/ROS scales. There are three stages for 15 min ( each for 5 min). The first stage is to relax with closing eyes. The second stage is to play a quick answer game. The last stage is to watch the landscape video. At the end of the experiment, subject was made filling in a questionnaire. The result shows that, “β-wave” indicates that auditory perception is less effective than visual or integration of visual and auditory perception on the reduction of stress in natural landscape. “Cognition” indicates that integration of visual and auditory perception is most effective on clarifying thoughts in natural landscape. “Fear/arousal” and “angry/aggressiveness” indicate that auditory perception is most effective on immersing negative emotions. “Perceptions” are effective on α-wave, β-wave, LF%, HF% and angry/aggressiveness indicators of stress reduction. “Environments” are effective on fear/arousal, anger/aggression, positive affect, attentiveness, relaxation, attention restoration, and cognition indicators of stress reduction. There are interactions between “perceptions” and “environments” of TP and angry/aggressiveness.