Working memory, perceptual priming, and the perception of hierarchical forms: Opposite effects of priming and working memory without memory refreshing

Abstract

Many everyday tasks require that we select from the environment stimuli relevant to our behavioral goals. Normally, this process of goal-directed selection may depend on a match taking place between goal-related information in working memory (WM) and incoming stimulus information (Desimone & Duncan, 1995;Duncan, 1998). Evidence supporting the role of top-down guidance of search to targets comes from experiments showing that search b benefits by providing participants with foreknowledge of targets (e.g., Anderson, Heinke, & Humphreys, in press;Wolfe, 2005), and that indeed some targets only "pop out" when foreknowledge is given (Hodsoll & Humphreys, 2001). Recent work suggests that these top-down effects are not confined to holding knowledge of the target, since there can also be effects of irrelevant information in WM. Downing (2000) had participants hold one stimulus in WM, then search for another target. The irrelevant cue in WM could reappear alongside the target or another item. Response times (RTs) were faster when the WM stimulus reappeared at the target's location (on valid trials) than when it fell elsewhere (on invalid trials). Importantly, this effect did not occur when the cue was presented but did not have to be maintained in memory. Soto, Heinke, Hump phreys, and Blanco (2005) further showed that irrelevant items in WM influenced the fastest RTs and the first saccades in search, and the effect occurred even when the WM cue was always irrelevant. This last result suggests that an irrelevant WM stimulus can capture attention automatically. Other studies have demonstrated effects, even with pop-out targets (Soto, Humphreys, & Heinke, 2006).Interestingly, in many of these studies, the WM item h constituted more of a "global" stimulus than the search target. For example, in Soto et al. (2005), the memory item d was an outline shape and the search target was an oriented line that appeared within the outline shapes presented in the search display. It could be that the WM stimulus captures attention at least partly because there is a bias toward the global properties of a display, as suggested by the "global precedence" hypothesis (Navon, 1977), which f holds that attention is biased toward global aspects of stimuli. When the WM cue matches early-emerging global properties of the search display, attention may be drawn to the global item matching the item in WM. It may also be that representing a stimulus in WM itself biases selection to the global level of a display, perhaps because the WM load reduces the resources available to process more local elements of a display. The biasing effects of WM on the selection of local and global properties of search displays were examined for the first time here. We had participants y g y carry out a global-local task in which they had to detect a Previous research has shown that stimuli held in working memory (WM) can influence spatial attention. Using Navon stimuli, we explored whether and how items in WM affect the perception of visual targets at local and global lev...

Identity but not size information in working memory biases attentional selection in hierarchical forms

“…In this study, we examined if an attentional window could be cued by holding a specific size representation in WM. A positive finding here would also extend prior results on cueing attention from WM to include size as well as colour, shape, and identity (Downing, 2000;Kim & Humphreys, 2010;Soto et al, 2005). Such a result would also support the idea that different levels of a hierarchical stimulus are selected by fitting an attentional window to the size of the to-be-selected element.…”

“…This held even when we varied the location of the size cue on each trial, so participants should not simple encode the area covered by the cue at a central location. Taken with the data from Experiment 1, the results indicate that memory representations of stimulus size do not guide visual attention towards a particular level of a hierarchical stimulus, when The effect on target absent trials can be conceptualized in at least two ways (see Kim & Humphreys, 2010). On one account the match of the identity of the cue to one level of the hierarchical stimulus biases attention to that level.…”

“…Following Kim and Humphreys (2010), we presented a memory cue that could sometimes have the same identity as a letter at the level of the subsequent global stimulus. As in Experiment 1, participants had to hold the size of the letter in WM so that, in this case, letter identity was irrelevant to memory performance.…”

“…However, the effects can also occur in nonspatial selection tasks, for example, with hierarchical letters, when a large letter cannot be spatially selected without also selecting the local elements (Kim & Humphreys, 2010). In their study of hierarchical selection, Kim and Humphreys (2010) had participants hold the identity of a letter in memory and then they had to detect a target in a following hierarchical letter. The identity of the letter in memory could match the target or it could match a distractor letter, at the opposite level of form to the target.…”

Seeing the Big Picture: Multitasking and Perceptual Processing Influences on Ad Recognition

“…However, no studies have looked at the effects of analytic/holistic style on perceptual processing or encoding of ads. Processing style affects how one pays attention to information during encoding, and divided attention may be more in line with global (versus local) attention (Kim, Jeong-Im, and Humphreys 2010). Therefore, holistic and analytic processors may respond differently to media multitasking.…”