Script knowledge in cortical dementia

Patients with probable Alzheimer's disease (DAT), frontal lobe dementia (FLD), and age- and education-matched normal controls recounted (generation task) and performed (behavioral enactment task) the steps from a high (making toast and coffee) and a low (changing a vacuum cleaner bag) frequency routine everyday activity for these two scripts. Patients performed and generated significantly fewer events and committed more errors than controls. Omission errors accounted for the majority of errors in all groups, while other types of errors (intrusion and sequencing) occurred infrequently. Evidence of planning and problem-solving deficits, as well as script fragmentation were common among patients. FLD patients were less likely than DAT patients to complete the behavioral enactment tasks and, at times, failed to safeguard their surroundings. Differential performance resulting in dissociations between tasks or scripts occurred more often in patient groups than in controls. FLD patients committed more errors in the toast and coffee script than in the vacuum bag script, experiencing particular difficulties when combining events into a complex routine; this may be the result of a greater working memory load required by the toast and coffee task.