The influence of perceptual and structural salience

The influence of perceptual and structural salience Florian Roser (florian.roeser@psychol.uni-giessen.de) Antje Krumnack (antje.krumnack@psychol.uni-giessen.de) Kai Hamburger (kai.hamburger@psychol.uni-giessen.de) Justus Liebig University Giessen, Department of Psychology, Experimental Psychology and Cognitive Science Otto-Behaghel-Strasse 10 F 35394 Giessen, Germany The present paper is concerned with the salience of landmarks. The term “salience” is mostly referred to perceptual psychology (e.g., Treisman & Gelade, 1980) and means that a salient object needs to stand out compared to other objects (e.g., different color or orientation). We here distinguish two kinds of landmark salience: structural salience and perceptual salience. Abstract Spatial cognition research has recently made much progress in understanding the cognitive representations and processes underlying human wayfinding. Many theoretical assumptions about the concept of landmark salience have been established. In this context it is important to define perceptual (or visual) and structural landmark salience. Structural salience is defined as the position of a landmark at an intersection. Perceptual salience is defined as the visual characteristic of a landmark. It must “stand out” from its surrounding to be perceptually salient. We investigated the influence of perceptual salience and the combination of perceptual and structural salience in landmark selection. We show for a spatial arrangement of four objects that the different object is preferred almost always. If the same spatial arrangement is interpreted as an intersection with a directional information, the participants’ preference is influenced by structural as well as perceptual salience. Findings are discussed within the context of landmark salience. Structural salience Keywords: landmark; perceptual salience; structural salience Introduction Human wayfinding is a particularly active field of spatial cognition research. People often have to navigate through new or familiar environments and that they, of course, do not want to get lost. Another reason is that wayfinding research is important for many basic and applied research fields, for instance, the study of spatial long-term memory and the development of user-friendly navigation systems. One of the central concepts in spatial cognition research is the landmark and the question how it can be defined. Consequently, several definitions and theories about the nature of landmarks and their characteristics exist. The most common assumption is that the potential landmark must have a high contrast to its immediate or wider surrounding (e.g., Presson & Montello, 1988; Janzen & van Turennout, 2004; Caduff & Timpf, 2008). Anything can serve as a landmark; natural, artificial, or man-made objects along a route that help us to find the way. Landmarks are helpful in wayfinding because they “stand out” of the environment, can serve as anchors (Couclelis, Golledge, & Tobler, 1987), are better remembered if a change of direction is required (Lee, Tappe & Klippel, 2002; Lee, Klippel & Tappe, 2003), and increase the quality of a route description (Denis, Pazzaglia, Cornoldi, & Bertolo, 1999). Structural aspects of landmarks refer to the contexts of landmarks in navigational tasks and may be divided into different aspects or gradations. It is generally accepted that landmarks must have a “prominent location in the environment” (Sorrows & Hirtle, 1999; p. 46). Furthermore, they can be separated into global and local landmarks (Steck & Mallot, 2000). Local landmarks are situated directly along the path and intersections (Klippel & Winter, 2005). Those at an intersection may again be divided, based on the route in the navigational task, into landmarks at a decision point or non-decision point, where a direction change is necessary/possible (Michon & Denis, 2001). Here we concentrate on landmarks directly located at an intersection were a decision is required (Lee et al., 2002; Peters, Wu, & Winter, 2010). In this context we define structural salience as a preference of a wayfinder for a landmark to be located at a specific position at an intersection. Strictly speaking structural salience is thereby not a property of a landmark itself but of its position at an intersection. Therefore we have to address the question how an intersection can be defined. A typical or even prototypical intersection is a cross intersection. At such intersections four possible positions for landmarks are available (figure 1). The true (physical) position of a landmark, on the right or on the left of the observer, is less important than the position in dependence to the direction of the turn to be made at the intersection. So the four positions can be defined as the positions before and behind the intersection and in direction or opposite to the direction of turn (see also Hamburger, Dienelt, Strickrodt, & Roser, 2013) and will be abbreviated as “turn based” in the following. The preferred positions for a landmark at such a prototypical intersection from an allocentric perspective are in direction of the turn with the main focus before the intersection (figure 2). These results