Academic journal article Attention, Perception and Psychophysics

Competition between Color Salience and Perceptual Load during Visual Selection Can Be Biased by Top-Down Set

Academic journal article Attention, Perception and Psychophysics

Competition between Color Salience and Perceptual Load during Visual Selection Can Be Biased by Top-Down Set

Article excerpt

Visual salience and perceptual load may both influence the efficiency of visual selection. Recently, Gibson and Bryant (2008) showed that perceptual load can dominate color salience in a distractor interference paradigm. The purpose of the present study was to investigate the possibility that knowledge (of color or load) may modulate the relative operation of these two mechanisms. Consistent with previous findings, perceptual load dominated color salience, but only in certain contexts in which display load was mixed and high-load displays preceded other high-load displays. More important, color salience dominated perceptual load in other contexts in which display load was mixed and low-load displays preceded high-load displays. In addition, color salience also dominated perceptual load in contexts in which display load was fixed and advance knowledge of load was available. Altogether, the present findings suggest that the competition between color salience and perceptual load can vary as a function of task context, thereby supporting top-down accounts, although the precise aspect of task context remains to be identified.

Attention researchers have long debated where in the stream of processing visual selection occurs. Over the past 15 years, Lavie and her colleagues (Lavie, 1995, 2005; Lavie & Cox, 1997; Lavie & Tsal, 1994) have suggested that the processing of both relevant and irrelevant items may proceed automatically, and in parallel, until attentional resources are consumed, at which point relevant items may be prioritized over irrelevant items. According to this perceptual load hypothesis, the selection of taskirrelevant items should appear to occur relatively late in the stream of processing, when the processing of taskrelevant items consumes relatively few resources, whereas the selection of task-irrelevant items should appear to occur relatively early in the stream of processing, when the processing of task-relevant items consumes relatively many resources (Lavie, 1995, 2005; Lavie & Cox, 1997; Lavie & Tsal, 1994).

Evidence in support of the perceptual load hypothesis has been obtained primarily from various distractor interference paradigms in which a target is presented with a distractor that is compatible, incompatible, or neutral with respect to the identity of the target item (see Lavie, 2005, for a review). In addition, perceptual load is typically manipulated by varying the number of nontarget items that are presented along with the target and distractor items (but see Lavie, 1995, and Lavie & Cox, 1997, for variations). In these studies, a late versus early locus of selection is associated with the presence or absence, respectively, of a distractor interference effect, which is typically defined as the difference in response time (RT) between the incompatible and neutral detractor conditions (Lavie, 1995). Previous studies have provided support for the perceptual load hypothesis by demonstrating the presence of a significant distractor interference effect under conditions of low perceptual load (signifying a relatively late locus of selection) and the absence of a significant distractor interference effect under conditions of high perceptual load (signifying a relatively early locus of selection; see Lavie, 2005, for a review).

However, other researchers have argued that this pattern of distractor interference may be more attributable to changes in distractor salience than to changes in perceptual load as the number of nontarget items increases. For instance, Eltiti, Wallace, and Fox (2005) argued that the onset of the distractor may be more salient, and therefore more likely to attract focal attention (Theeuwes, 1991, 1992, 1994, 2004), when only the target and distractor appear in the display (as in the low-load condition). In contrast, the distractor may be less salient, and therefore less likely to attract focal attention, when several additional items also onset simultaneously with the target and distractor in the display (as in the high-load condition). …

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.