Time course of object identification: Evidence for a global-to-local contingency.

Abstract

A time course contingency is the modification of later phases of object recognition contingent upon stimulus information extracted earlier in processing. It can increase the efficiency of later processing and reduce computational burdens. This idea was instantiated within a global-to-local model and supported in 4 integration priming experiments, in which primes and target objects were presented briefly and then masked. In Experiments 1-3, global and coarse-grained common-feature primes presented early in processing facilitated discriminations between similarly shaped objects, even though they provided no discrimination-relevant information. In Experiment 4, global primes were more effective than local primes early in processing, whereas local primes were more effective than global primes late in processing.An important goal in the study of perceptual identification is to specify the time course of the relevant processes. In this endeavor, marked success has been achieved with pleasingly simple feature accumulation models, in which features are extracted over time and continuously activate form-level representations in a passive, bottom-up manner. For example, such models account for a wide variety of data on pattern and word perception (e.g., Estes, 1978;Keren & Baggen, 1981; Massaro & Sanocki, in press;Oden, 1979;Sanocki, 1990Sanocki, , 1991bShibuya & Bundesen, 1988;Townsend, 1981).The assumption of a bottom-up flow of information can be elaborated on to begin to account for object identification (e.g., Biederman, 1987). However, the adequacy of a bottom-up approach becomes questionable when the computational burdens of identifying three-dimensional objects are considered. Objects vary in size, orientation, and details of instances. They have many features that must be bound together, and objects with moving parts can vary greatly in shape. Any object can appear under different lighting conditions or be partially occluded. There is evidence indicating that the perceptual system can be sensitive to details of instances of letters (e.g., Sanocki, 1987Sanocki, , 1988Sanocki, , 1990Sanocki, , 1991b and objects (e.g., Jacoby, Baker, & Brooks, 1989;Price & Humphreys, 1989) and to differing object orientations (e.g., Jolicoeur, 1985;Palmer, Rosch, & Chase, 1981). This sen- Correspondence concerning this article should be addressed to Thomas Sanocki, Department of Psychology, BEH 339, University of South Florida, Tampa, Florida 33620-8200. Electronic mail may be sent to sanocki@figment.csee.usf.edu. sitivity may extend to differing part configurations and sufficiently different lighting conditions. If during object identification the perceptual system considered such factors for an unconstrained set of alternatives, the enormous number of combinations of stimulus features and feature-object mappings would create combinatorial explosion.These considerations support hypotheses that are not strictly bottom-up in nature. Of interest is the possibility that computational burdens may be reduced by using early stimulus info...

Information-accumulation theory of speeded categorization.

“…Although this assumption seems justified in some tasks and with certain stimuli (e.g., Lamberts & Freeman, 1999a;Townsend, Hu, & Ashby, 1981), there is considerable evidence in the literature to suggest that independence does not always hold (e.g., Townsend & Ashby, 1982;Townsend et al, 1984). For instance, Sanocki (1991Sanocki ( , 1993 showed that stimulus information that is extracted early in processing can modify later phases of object recognition. Such a contingency-based processing scheme reduces the computational burden on the system.…”

“…A crucial assumption of decisionbound theory is that the perceptual effect of a stimulus can be represented as a point in a multidimensional space and that repeated stimulus presentations do not always result in the same perceptual effect (e.g., Ashby & Gott, 1988;Ashby & Lee, 1991;Ashby & Maddox, 1992, 1993. It is further assumed that practiced observers divide the perceptual stimulus space into regions, which correspond to categories.…”

Face perception: An integrative review of the role of spatial frequencies

“…A great deal of empirical evidence points toward a fixed integration process that starts with the coarse information (contained in LSFs) and then moves on to the fine information (contained in HSFs), similar to object or form perception in general (e.g. Hughes, Face Perception 18 Fendrich & Reuter-Lorentz, 1990;Hughes, Nozawa & Kitterle, 1996;Kimchi, 1992;Navon, 1977;Sanocki, 1993) . However, some empirical evidence has also indicated processing can be flexible, as processing is sometimes coarse to fine, while others it is fine to coarse.…”

How Different Spatial-Frequency Components Contribute to Visual Information Acquisition.

“…In interactive GtL theories (e.g., Navon, 1977;Sanocki, 1991Sanocki, , 1993Sanocki, , 2001, not only does global information precede local information but acquisition of local information also depends on the amount of already acquired global information. That is, acquired global information provides a spatial framework, within which local information can be interpreted and integrated-and the more complete the global information, the more efficient is such local processing.…”