The 'Titanic Effect' was first observed in a working memory task with Ischaemic Vascular Dementia (IVD; Lamar et al., 1999). This phenomenon refers to the inability to maintain mental set throughout an entire task. For the present study, it was hypothesized that this effect would also be observed for IVD on a test of phonemic letter fluency (FAS; Benton & Hamsher, 1976). Although commonly used as a clinical tool for assessing retrieval of verbal information, the FAS test is also believed to be an effective measure of frontal systems functioning (Baldo & Shimamura, 1998). While Libon et al. (1997) have previously demonstrated that AD and IVD differ in FAS total word output, the current investigation examined differences in proportion of output over 15s increments. It was identified that the IVD (n=28) produced a significantly larger proportion of words within the first 15s (59% of total ouput) than the AD (n=31; 45%) and healthy older adults (n=39; 40%) [e.g., for letter F, F(2, 95)= 80.24, p < .001]. As the task progressed, however, the performance output of IVD continued to drop dramatically below (at 45-60s output = 11%) that of the AD (18%) and healthy older adults (19%). Although the output of the normal controls was greater throughout task than the AD participants, the proportion of responses across time intervals was similar for both groups [F (1, 67) = 1.12, p = .29]. This finding not only underscores the importance of examining responses over time, but also the utility of this brief measure of frontal system functioning for individuals suffering from dementia.