Academic journal article Attention, Perception and Psychophysics

The Time Course of Configural Change Detection for Novel 3-D Objects

Academic journal article Attention, Perception and Psychophysics

The Time Course of Configural Change Detection for Novel 3-D Objects

Article excerpt

The present study investigated the time course of visual information processing that is responsible for successful object change detection involving the configuration and shape of 3-D novel object parts. Using a one-shot change detection task, we manipulated stimulus and interstimulus mask durations (40-500 msec). Experiments 1A and 1B showed no change detection advantage for configuration at very short (40-msec) stimulus durations, but the configural advantage did emerge with durations between 80 and 160 msec. In Experiment 2, we showed that, at shorter stimulus durations, the number of parts changing was the best predictor of change detection performance. Finally, in Experiment 3, with a stimulus duration of 160 msec, configuration change detection was found to be highly accurate for each of the mask durations tested, suggesting a fast processing speed for this kind of change information. However, switch and shape change detection reached peak levels of accuracy only when mask durations were increased to 160 and 320 msec, respectively. We conclude that, with very short stimulus exposures, successful object change detection depends primarily on quantitative measures of change. However, with longer stimulus exposures, the qualitative nature of the change becomes progressively more important, resulting in the well-known configural advantage for change detection.

Observers are often "blind" to large changes to a scene when these changes occur simultaneously with a brief disruption-a phenomenon referred to as change blindness (see Simons, 2000, and Simons & Levin, 1997, for reviews). Although there are limits to the conclusions that may be drawn from change blindness studies (Simons & Rensink, 2005), their results do provide important insights into the kinds of visual information that underlie change detection. Spatial layout is one type of information that is likely to be retained in scene representations to support successful change detection. It refers to the overall positioning or placement of the items or elements within a scene/image and does not rely on semantics or the identity of those elements (Hochberg, 1968; Pomerantz, 1983). The retention and representation of spatial layout information is well supported by change detection research with scenes (Aginsky & Tarr, 2000; Hollingworth & Henderson, 2002; Rensink, 2000a; Simons, 1996). Simons (1996) investigated change detection for scene displays consisting of multiple objects (both novel and common objects). He found that changes to the spatial layout or configuration of the display were better detected than changes involving either the switching of objects or the replacement of one of the objects. He concluded that the information about the spatial configuration of the scene is easily encoded and represented visually, whereas objectspecific information is not.

Recent change detection research suggests that spatial layout or configural information is also important in the processing of single, complex 3-D objects, as well as of multiobject scenes (Favelle, Hayward, Burke, & Palmisano, 2006; Favelle, Palmisano, Burke, & Hayward, 2006; Keane, Hayward, & Burke, 2003). Configural information, or configuration, is used here to refer to the spatial layout of an object's parts (i.e., the gross part structure of an object). For example, the configuration of one of the objects used in the present study (see Figure 1) could be described as a central body part with three smaller parts, one each attached at the top left, bottom middle, and top right of the body. This is consistent with the idea that the visual system bases object representation on a "part skeleton" that emphasizes structural properties (e.g., the number, location, and spatial relations of parts) over metric properties (Barenholtz, Cohen, Feldman, & Singh, 2003; Blum, 1973; Kimia, Tannenbaum, & Zucker, 1995). Note that the shape of the parts is not included in a description of configural information. …

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.