as opposed to healthy controls, the degree of similarity between search items affects the ability to selectively attend to relevant targets. Similar results were observed in Schaefer, where a study of visual selective attention in AD was conducted by varying the physical characteristics of a selective cancellation task. Dementia with Lewy bodies Dementia with Lewy bodies is characterised by the formation of Lewy bodies in the cerebral cortex, substantia nigra, locus coeruleus, and components of the basal forebrain cholinergic system. Clinical features include a cortical dementia and confusion, Parkinsonism, sensitivity to neuroleptic drugs, and psychiatric manifestations such as recurrent and well-formed hallucinations, particularly in the early stages of the disease. Because of an overlap in clinical symptoms, differentiating dementia with Lewy bodies from Alzheimer's type dementia can sometimes prove to be difficult. However, differences in attentional functioning capacities in patients have been found to distinguish these two neurodegenerative disorders. Although areas of attentional processing such as divided attention, shifting processes, or inhibition are impaired in both Alzheimer's disease and dementia with Lewy bodies (DLB), research has shown these deficits to be more prominent in DLB patients than AD patients, coinciding with impaired selective attention, particularly in the visual modality, or their ability to selectively allocate attention to specific stimuli. Visual selective attention is typically impaired in this disease. In a study by Peters et al., individuals with AD or DLB completed a Rapid Serial Visual Presentation (RSVP) task. This RSVP paradigm involves the presentation of visual stimuli at the same location in rapid sequence. Each stimulus was presented rapidly, and the target stimulus was a different colour (shown in red) than the distractors (black). The stimulus set consisted of 24 English letters as targets (excluding I and O), and the digits 2–9 served as distractors. Results suggested that there were definite differences in terms of ability to inhibit distractor information in the attentional dynamics between AD and DLB patients and healthy controls, however, selective attention deficits are shown to be more severe in DLB patients than AD patients. Both DLB and AD patients showed a decrease in accuracy in the test. Patients with DLB were more severely impaired in visual selective attention compared to both AD patients and healthy controls. Visual selective attention requires many underlying cognitive processes, including detection of important sensory and perceptual information, the ability to inhibit information that is irrelevant to the task, and the ability