Academic journal article Attention, Perception and Psychophysics

The Role of Visual Working Memory (VWM) in the Control of Gaze during Visual Search

Academic journal article Attention, Perception and Psychophysics

The Role of Visual Working Memory (VWM) in the Control of Gaze during Visual Search

Article excerpt

We investigated the interactions among visual working memory (VWM), attention, and gaze control in a visual search task that was performed while a color was held in VWM for a concurrent discrimination task. In the search task, participants were required to foveate a cued item within a circular array of colored objects. During the saccade to the target, the array was sometimes rotated so that the eyes landed midway between the target object and an adjacent distractor object, necessitating a second saccade to foveate the target. When the color of the adjacent distractor matched a color being maintained in VWM, execution of this secondary saccade was impaired, indicating that the current contents of VWM bias saccade targeting mechanisms that direct gaze toward target objects during visual search.

The successful completion of almost any goal-directed behavior requires orienting attention efficiently to taskrelevant objects in the world. To write and mail a letter, for example, one must shift one's eyes among several objects (paper, pen, envelope, stamp) as each object is required by the task (Land & Hayhoe, 2001). Unless an object is already attended or draws attention to itself directly, a visual search operation is required to select the relevant object from among other visible objects. In real-world behavior, this selection is controlled primarily by top-down mechanisms. The bottom-up visual salience of an object is unlikely to be strongly correlated with task relevance (Henderson, Brockmole, Castelhano, & Mack, 2007), and bottom-up salience is unlikely to change systematically as a function of evolving task demands. Thus, visual cues alone would be insufficient to guide attention and the eyes in real-world tasks. Top-down control over search and selection is required and is likely to be dominant in the absence of salient, transient events that capture attention (Franconeri, Hollingworth, & Simons, 2005; Yantis & Jonides, 1984).

One means by which top-down control over attention can be exerted is through an interaction between attention and visual working memory (VWM; Chelazzi, Duncan, Miller, & Desimone, 1998; Chelazzi, Miller, Duncan, & Desimone, 1993; Desimone & Duncan, 1995; Duncan & Humphreys, 1989; Hollingworth, Richard, & Luck, 2008; Olivers, Meijer, & Theeuwes, 2006; Soto, Heinke, Humphreys, & Blanco, 2005; Soto, Humphreys, & Heinke, 2006; Woodman, Luck, & Schall, 2007).1 The VWM system is a set of processes that supports the maintenance of perceptual information from a small number of objects across relatively brief delays and perceptual disruptions (for a review, see Luck, 2008b). In search, VWM can provide top-down control by maintaining the visual properties of the search target, allowing each attended object to be categorized as either the target or a nontarget (Duncan & Humphreys, 1989). In addition, the maintenance of object properties in VWM can interact with the sensory representation of visible objects that share those properties (Chelazzi et al., 1998; Chelazzi et al., 1993), biasing spatial attention toward the location of a remembered object. Specifically, the biased competition model (Chelazzi et al., 1993; Desimone & Duncan, 1995) holds that VWM retention involves the sustained activation of a perceptual representation of the remembered object. Subsequent perceptual processing of an object that shares the preactivated features will be facilitated, and that object will come to dominate the sensory response, biasing spatial selection during search toward the location of an object that matches memory (Olivers et al., 2006; Soto et al., 2005).2 In this manner, when the pen is required by the task, remembered features of the pen (red, cylindrical, small) could be retrieved from long-term memory (LTM) and activated in VWM. The maintenance of these features in VWM would then bias spatial attention during search toward the location of an object with matching features, such that the pen is efficiently selected from among competing objects and becomes available for use in the task. …

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.