Roberts et al. (1994) and Mitchell et al. (2002) presented healthy young adults with a WM task concurrent with an AST, and reported that prolonged latencies and higher directional error rates were observed for young participants that were comparable to that found among much older adults in other studies (Olincy et al., 1997; Sweeney et al., 2001; Eenshuistra et al., 2004). This was interpreted as evidence suggesting that a reduction in WM capacity is the likely source of poor AST performance. In contrast, it has been argued that the failure to inhibit the prepotent response may account for the poorer performance across the older samples in the AST (Butler and Zacks, 2006; Ryan et al., 2006). This is because it is essential to inhibit this response towards a visual stimulus (e.g., Godijn and Kramer, 2006). Butler and Zacks (2006) investigated the extent to which IC could explain age-related AST impairments. Antisaccades that are triggered by the onset of a peripheral stimulus require IC to suppress the prepotent prosaccade response to that stimulus (Theeuwes et al., 1999), while antisaccades signaled by a central directional arrow require endogenous planning, but clearly have reduced inhibitory requirement, as there is no peripheral stimulus to capture visual attention. Thus, a marked increase in AST errors or latencies with age, in a peripheral onset condition, in comparison with a central cue, would suggest support for a specific IC deficit with age. In the Butler and Zacks (2006) study, the older adults generated longer reaction times when the inhibitory load of the AST was increased using the onset of the peripheral stimulus, which is compatible with the hypothesis of an age-related decline in IC. However, the peripheral vs. central cue manipulation yielded no group effect on AST errors between the young and older participants.