Previous research suggests that the use of valid symbolic cues is sufficient to elicit voluntary shifts of attention. The present study interpreted this previous research within a broader theoretical context which contends that observers will voluntarily use symbolic cues to orient their attention in space when the temporal costs of using the cues are perceived to be less than the temporal costs of searching without the aid of the cues. In this view, previous research has not addressed the sufficiency of valid symbolic cues, because the temporal cost of using the cues is usually incurred before the target display appears. To address this concern, 70%-valid spatial word cues were presented simultaneously with a search display. In addition, other research suggests that opposing cuedependent and cue-independent spatial biases may operate in these studies and alter standard measures of orienting. After identifying and controlling these opposing spatial biases, the results of two experiments showed that the word cues did not elicit voluntary shifts of attention when the search task was relatively easy but did when the search task was relatively difficult. Moreover, the findings also showed that voluntary use of the word cues changed over the course of the experiment when the task was difficult, presumably because the temporal cost of searching without the cue lessened as the task got easier with practice. Altogether, the present findings suggested that the factors underlying voluntary control are multifaceted and contextual, and that spatial validity alone is not sufficient to elicit voluntary shifts of attention.
Keywords Spatial attention . Spatial cuing, Symbolic attention control . Voluntary attention controlSpatial symbols are often used to elicit voluntary shifts of attention in the laboratory, though these symbols may also elicit involuntary (or automated) shifts of attention (Friesen & Kingstone, 1998;Friesen, Ristic, & Kingstone, 2004;Gibson & Bryant, 2005;Ho & Spence, 2006;Hommel, Pratt, Colzato, & Godijn, 2001;Jonides, 1981;Leblanc & Jolicoeur, 2010;Pratt, Radulescu, Guo, & Hommel, 2010;Ristic, Friesen, & Kingstone, 2002;Ristic & Kingstone, 2006Tipples, 2002Tipples, , 2008. For the past 30 years, the primary tool used to study attentional shifts in response to such symbolic cues has been the spatial cuing paradigm (Posner, 1980;Posner, Snyder, & Davidson, 1980). In this paradigm, observers are shown visual displays and are required to detect, discriminate, or identify some target stimulus presented in their periphery while keeping their eyes fixated on a central location. To aid in their search for the target, a symbolic cue is often shown at fixation, which correctly identifies the location of the target on some trials (i.e., valid trials) but not on others (i.e., invalid trials). In most variations of the spatial cuing paradigm, there is only one target present in each display, accompanied by visually similar nontarget distractors. Under these conditions, observers can choose to use the cue to l...