g., Brandt and Stark, 1997, Johansson et al., 2012 and Spivey and Geng, 2001). Further support comes from neuropsychological studies that have demonstrated links between the Frontal Eye Field (FEF) and spatial working memory performance (e.g., Cabeza and Nyberg, 2000, Campana et al., 2007 and Gaymard et al., 1999), while experiments in non-human

primates suggest activation in oculomotor regions such as FEF signals the location of memorized targets even after they have disappeared (Bruce and AZD5363 molecular weight Goldberg, 1985 and Sommer and Wurtz, 2001). However, an alternative to the eye-movement theory is that VSWM relies on shifts in covert spatial attention (i.e., the see more ability to shift attention to locations without executing any overt eye movement). For example, Awh and Jonides, 2001 and Awh et al., 1998 found reaction times were faster when targets

appeared at locations held in working memory, and that participants’ spatial working memory was disrupted when they were prevented from attending to memorized locations during a retention interval. Furthermore, Godijn and Theeuwes (2012) report that memory for a sequence of locations indicated by numbered peripheral items is unaffected by requiring participants to maintain fixation, in comparison to a condition in which they are free to execute overt eye movements during a retention interval. Conversely, however, Belopolsky and Theeuwes

have reported being unable to find evidence that spatial attention interacts with spatial working memory during performance of a match to sample task (2009a). We argue that there are several reasons why previous studies in the literature may have struggled to differentiate between Rho eye-movement and attention-based mechanisms in VSWM. One major problem has been the apparent lack of any experimental paradigm that can reliably decouple attentional processes from oculomotor control processes in VSWM. This arises because executing an eye-movement necessarily involves a participant also producing a comparable shift of covert attention (Shepherd, Findlay, & Hockey, 1986). Equally, we argue it is insufficient to investigate oculomotor involvement in VSWM by comparing conditions in which participants move their eyes to conditions where their gaze remains fixated (e.g., Godijn & Theeuwes, 2012), as participants may still engage in saccade preparation even without subsequent execution. An additional limitation of previous studies is that many studies have adopted a selective interference paradigm in which participants are required to produce eye-movements during the rehearsal period of a spatial working memory task (e.g., Guerard et al., 2009, Pearson and Sahraie, 2003 and Postle et al., 2006).