According to previous research, older people generate increased latencies and/or an increase in the proportion of directional errors in the AST (e.g., Fischer et al., 1997; Eenshuistra et al., 2004). The aim of the present research was to determine whether WM or IC was the source of this effect. The key findings revealed the following: First, the older adults were substantially slower in the AST-go/no-go task. Clearly, the additional inhibitory load had a disproportionate effect on the saccade slowing for the older group. Saccade latencies in AST-go/no-go task were markedly slower than AST-mem latencies. This slowing was probably due to the element of response uncertainty in the AST-go/no-go task. This appears to have resulted in a general response hesitancy presumably due to the 50% chance that any given trial will require an eye movement away from the target, or complete inhibition of the saccade. Participants did not know whether they would be required to execute an antisaccade, or to maintain fixation on the central cross.