不一致的視覺與物理可及性對空間感知之影響

Abstract

空間感知是景觀與戶外遊憩領域長期關注的核心議題，亦是衡量環境規劃與設計的重要指標。Stamps的滲透性理論（Permeability Theory）將封閉、寬敞等抽象空間感受轉化為個體在環境中感知與移動的能力，即視覺可及性與物理可及性。然而，過去文獻多採用遮蔽物間隙或地面面積等視覺因素作為物理可及性操控變項，導致兩種可及性長期處於高度共變狀態，也忽略了個體對可移動性的判斷亦包含對環境中非視覺的認知因素。此外，空間的垂直與水平界面對個體在視覺與移動上的限制也存在本質上的差異，垂直界面中多為空間中的阻礙或邊界，通常同步限制視線與移動，水平界面則構成支撐移動的表面，通常僅改變移動的難易程度，但過去研究尚未系統性區分垂直與水平兩類空間維度在感知機制上的影響差異。 為填補以上研究缺口，本研究以沉浸式虛擬實境(IVR)技術做為研究工具，並透過虛擬實驗場景的設計將視覺可及性與物理可及性分離，同時納入非視覺的認知因素，藉此探討兩種可及性不一致時個體的空間感知變化。本研究依空間維度分為兩個子研究，共包含四個實驗，藉此釐清垂直與水平維度下的空間感知影響機制。研究一聚焦於空間垂直遮蔽物的討論，並以視覺滲透性、遮蔽物間距以及材料形變資訊做為操控變項；研究二則針對水平地面特性進行探討，透過壕溝與水池建立不遮擋視線的空間邊界，同時以地面面積、地面材質、邊界寬度以及深度資訊做為操控變項。 透過四個實驗的結果本研究獲得以下研究發現。首先，在控制視覺刺激的條件下，環境中的認知因素能顯著影響個體對物理可及性的主觀判斷，進而改變空間封閉與寬敞感知，且此影響力受到視覺因素的調節。在空間垂直界面，當遮蔽物間距處於中等大小時，個體無法單純仰賴視覺判斷穿越邊界的可能性，因此材料是否具備可形變的物理特性便成為評估物理可及性的關鍵；在空間水平界面，水池深度亦受到寬度的調節，只有當水池寬度在視覺上看起來不可跨越時，深度的認知因素才會顯著影響物理可及性判斷。此發現進一步證實了由認知因素所引發的心理預期與經驗投射，能打破單純依賴視覺特徵評估空間的限制。 其次，本研究釐清了空間垂直與水平界面在兩種可及性影響機制上的差異。在垂直界面，研究證實視覺與物理可及性對空間感知具有顯著的加乘作用，推測其原因在於空間垂直界面具備實體遮蔽的特性，多半會同步造成視覺的遮擋與移動的限制，使得個體傾向將兩者資訊進行整合並形塑最終空間感知；相較之下，水平界面本質上允許視線穿透，因此個體會將視覺通透感與移動可能性視為兩套獨立的評估系統，兩者在水平情境中無顯著交互作用。 最後，針對視覺與物理可及性的關係探討，本研究證實即便在兩者不一致的情境下在統計上仍呈正相關，符合視覺通透暗示移動便利的直覺慣性。然而，透過多因子模型分析後則發現，當環境趨於極端或納入認知因素時，個體的視覺慣性便會被打破，進而導致兩種可及性的共變關係產生分離。 綜上所述，本研究進一步探討兩種可及性不一致下的空間感知變化，並深入比較垂直與水平維度的影響機制差異，亦證實心理認知對空間感知的影響力，為未來相關研究與空間設計應用提供了更完整的理論基礎。

Spatial perception is a long-standing core issue in the fields of landscape and outdoor recreation, serving as a critical metric for environmental planning and design. Stamps’ permeability theory operationalizes abstract spatial feelings, such as enclosure and spaciousness, into an individual's capacity to perceive and move through an environment, categorized as visual accessibility and physical accessibility. However, previous literature has heavily relied on visual cues—such as obstacle gaps or ground area—as proxies to manipulate physical accessibility. This has left the two types of accessibility highly positively correlated while overlooking the fact that judgments of environmental traversability also involve cognitive information. Furthermore, previous studies have failed to systematically distinguish between vertical and horizontal dimensions in perceptual mechanisms. Vertical elements act as spatial barriers that restrict both vision and movement simultaneously, whereas horizontal elements form the supporting surfaces where alterations merely affect the ease of locomotion. To bridge these research gaps, this study utilizes Immersive Virtual Reality (IVR) to decouple visual and physical accessibility within virtual experimental scenes while incorporating cognitive environmental information. This setup enables investigation of changes in spatial perception when visual and physical accessibility are inconsistent. Comprising two sub-studies with four experiments grouped by spatial dimensions, this research clarifies the underlying perceptual mechanisms. Study 1 focuses on vertical obstacles, manipulating visual permeability, obstacle spacing, and material deformability. Study 2 shifts to horizontal ground characteristics, utilizing trenches and pools to establish spatial boundaries that do not block the line of sight, while manipulating ground area, surface material, boundary width, and depth information. The findings across the four experiments yield three key insights. First, under controlled visual stimuli, cognitiveinformation significantly influences subjective judgments of physical accessibility, thereby altering perceptions of spatial enclosure and spaciousness; notably, this effect is moderated by visual factors. Regarding vertical elements, when obstacle spacing is intermediate, individuals cannot rely solely on visual cues to judge traversability, making material deformability the critical factor for assessing physical accessibility. Regarding horizontal elements, pool depth is moderated by width; depth information significantly impacts physical accessibility judgments only when the pool width appears visually uncrossable. These findings further demonstrate that psychological expectations and experience-based projections elicited by cognitive information can overcome the limitations of relying solely on visual cues when evaluating space. Second, this study elucidates the distinct perceptual mechanisms driven by vertical versus horizontal spatial factors. For vertical elements, visual and physical accessibility exert a significant multiplicative effect on spatial perception. Because vertical elements function as physical barriers that simultaneously obstruct vision and restrict movement, they typically obstruct vision and restrict movement concurrently, leading individuals to integrate both channels of information into a unified spatial perception. Conversely, horizontal elements naturally allow for visual penetration; individuals thus treat visual openness and locomotion potential as two independent evaluation systems, showing no significant interaction effect in horizontal contexts. Finally, regarding the relationship between visual and physical accessibility, this study confirms that they remain statistically positively correlated even in inconsistent scenarios, aligning with the intuitive inertia that visual openness implies ease of movement. However, multi-variable model analysis reveals that when environments become extreme or when cognitiveinformation is introduced, this visual inertia is disrupted, causing the covariant relationship between the two accessibilities to decouple. In conclusion, this study further explored how spatial perception changes when visual and physical accessibility are inconsistent, compared the underlying mechanisms across vertical and horizontal dimensions, and confirmed the influence of psychological cognition on spatial perception. These findings provide a more comprehensive theoretical foundation for future research and spatial design applications.