Academic journal article Perception and Psychophysics

Representations of Scene Layout Can Consist of Independent, Functional Pieces

Academic journal article Perception and Psychophysics

Representations of Scene Layout Can Consist of Independent, Functional Pieces

Article excerpt

A scene prime can induce a mental representation of layout that is functional in the sense that it facilitates the processing of depth relations in a subsequent same-scene target. Five experiments indicated that the representation can consist of separate and independent functional regions. In each experiment, primes with as many as four unrelated regions facilitated spatial processing within each region. The prime representations were functional despite structural discontinuity at region borders. The results indicate a limitation in the importance of structural constraint in representations of scene layout. However, when structural disruption occurred within regions that were perceived (Experiment 5), spatial processing was slowed. The results suggest that scene representation is more top down than is scene perception; the effects of structural disruption were overcome within representations, but not within perception.

In what ways might representations of a scene contribute to the ongoing perception of a scene? Potential functions include integration and prediction of scene structure (Henderson & Hollingworth, 1998; Hochberg, 1978; Intraub, 2002), facilitation of object processing (Biederman, 1981 ; Boyce, Pollatsek, & Rayner, 1989; Davenport & Potter, 2004), and navigation (e.g., Andersen, Hahn, & Saidpour, 2001; Vishton & Cutting, 1995). Another possible function, studied in the present research, is facilitating the processing of depth relations in familiar scenes (Sanocki, 2003; Sanocki & Epstein, 1997). Our concern is with representations of scenes that are familiar to viewers and with the role that structural constraints might play within those representations (Sanocki, 2003). Structural constraints are based on regularities of the environment, such as continuity of edges and surfaces. Organizational processes based on structural constraints are essential within many theories of perception (e.g., Biederman, 1987; Marr, 1982; Palmer, 1999; Palmer & Rock, 1994; Shepard, 1984; Wertheimer, 1924/1950; Witkin & Tenenbaum, 1983). We examined whether structural constraints are also critical for scene representation (e.g., Grossberg & Mingolla, 1985; Hummel & Biederman, 1992; Sanocki, 2003; Shepard, 1984) by exploring their role within functional representations of scene layout.

Scene Priming and Representations of Scene Layout

The claim that layout representations are functional is based on scene-priming effects. A scene prime (see, e.g., Figure 1A) is presented for 1 sec, to activate the scene representation, or a control prime is presented (Figure 1B). The prime is followed by a brief blank interval and then a target picture that may be the same as the scene prime, except for two uniquely colored probes marking locations (e.g., two red probes; Figure 1C). Observers indicate which probe is closer to viewpoint (camera point) in the depicted space. Reaction time (RT) is the main measure (accuracy is usually high). The scene-priming effect is that RTs are shorter for spatial probes following same-scene primes than following control primes or different-scene primes (Sanocki, 2003; Sanocki & Epstein, 1997). The interpretation is that the scene prime activated a representation of the scene's layout, which facilitated the subsequent processing of spatial relations in the scene.

Previous results rule out many alternative explanations. The results indicate that the facilitation effect depends on information about the layout of objects and surfaces, rather than on the mere presence of objects and surfaces (Sanocki, 2003, Experiment 1). Furthermore, of particular interest here is the finding that the scene representations are functional across a broad scenic scope. That is, scene primes facilitated spatial processing across complex scenes, involving eight or more objects and major surfaces and many different spatial relations (Sanocki, 2003, Experiment 3). The scope of processing facilitated by a given prime can be illustrated with a probe activity map, which shows the set of spatial relations (probe pairs within the targets) that can follow a prime (Figure 2). …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.