A further weakness of dual-task paradigms that require participants to actively produce responses such as eye-movements is that it can become difficult to distinguish selective interference effects from more general attentional interference that results from overall task difficulty (for related discussion, see Pearson & Sawyer, 2011). One paradigm that addresses these limitations is the abducted-eye paradigm, in which oculomotor preparation is prevented by presenting stimuli to a region of participants’ visual field that lies beyond their oculomotor range ( Craighero et al., 2004 and Smith et al., 2010). Crucially, this paradigm allows the role of the oculomotor
system in spatial working MK-2206 solubility dmso memory to be examined independently from any confounding effect of saccade preparation on covert attention. Support for this position derives from studies of patients suffering oculomotor deficits which have demonstrated that attention can be covertly oriented to locations that lie beyond the possible range of their eye movements ( Gabay et al., 2010, Rafal et al., 1988 and Smith et al., 2004). Following from this, Smith et al. have previously shown that stimulus-driven
selleck screening library shifts of attention are abolished by placing participants in an eye-abducted position, while their volitional attentional orienting remains unimpaired ( Smith et al., 2012 and Smith et al., 2014). Recently we have used a version of the abducted-eye paradigm to explore oculomotor involvement in spatial working memory (Ball, Pearson, & Smith, 2013). Participants were required to fixate the center of a display while the other eye was patched, and their head and body were then rotated until there was an angle of 40° between their trunk midline and the center of PRKD3 gaze (Fig. 1A). This manipulation meant that while participants could still see everything in the
display, they were physically unable to make eye-movements further into the temporal hemifield. While participants were required to maintain central fixation in all conditions, eye-movements into the nasal hemifield remained physically possible even in the eye-abducted position. During the study memoranda were presented wholly in the nasal hemifield or the temporal hemifield. Using this paradigm the oculomotor account of VSWM made a clear prediction: Eye-abduction should only disrupt spatial memory if memoranda were presented in the temporal hemifield, as this was the only condition in which saccadic preparation was rendered physically impossible. The results of Ball et al. (2013) clearly showed eye-abduction was associated with impaired performance on the Corsi Blocks task (De Renzi, Faglioni, & Previdi, 1977), but not with performance of the Visual Patterns task (Della Sala, Gray, Baddeley, Allamano, & Wilson, 1999), the Arrow Span task (Shah & Miyake, 1996), a size comparison task (Thompson et al., 2006), or a visually-presented digit span task (Dempster & Zinkgraf, 1982).