Neuropsychologia 40 (2002) 2000–2012 Spatial shifts in visual attention in normal ageing and dementia of the Alzheimer type Andrea Tales a,1 , Janice L. Muir a , Anthony Bayer b , Robert J. Snowden a,∗ a School of Psychology, Cardiff University, Cardiff CF10 3YG, Wales, UK b Department of Geriatric Medicine, Llandough Hospital, Penlan Road, Penarth CF64 2XX, Wales, UK Received 18 June 2001; received in revised form 26 March 2002; accepted 9 April 2002 Abstract Using a spatial-cueing paradigm, we assessed the ability of Alzheimer’s disease patients, age-matched controls and younger participants to use cues to guide attention to the location indicated by the cue. In separate experiments, we attempted to isolate cues that attract attention automatically (exogenous cueing) and those that require the wilful movement of attention (endogenous cues). We found significant cueing effects for all three groups of participants for both types of cue. However, the group with Alzheimer’s disease showed far greater cueing effects when using an exogenous cue, whilst no difference between group’s ability to use the cue was found for the endogenous cue. No differences in cueing were found for either cue type as a function of normal ageing. We further tested whether the differences in cueing found in the group with Alzheimer’s disease was due to a generalised slowing of function. After transforming the data to take account of the overall slowing of all responses in this group, we still found significant differences between this group and the control groups. We conclude that patients with Alzheimer’s disease have an abnormality in automatic, but not controlled visuospatial attention. © 2002 Elsevier Science Ltd. All rights reserved. Keywords: Alzheimer’s disease; Cueing paradigm; Attention 1. Introduction Whilst dementia of the Alzheimer type (DAT) is often considered an impairment of memory, it is now recognised that there are also disturbances of attentional processes which may be apparent at early stages of the disease [34,36,37]. Some changes in attentional processes also ap- pear to accompany the normal ageing process [9,14]. Thus, we are left to consider whether the impairments in function seen in DAT can be considered extensions of the normal ageing process, or whether they differ in some fundamental manner. In other words, are differences for a particular task or psychological function (if there are any) quantitative or qualitative? In a similar vein, it has often been shown that older participants tend to perform tasks slower than younger controls. It has been suggested, therefore, that many results in the literature can be accounted for by a generalised slow- ing, rather than an impairment in a specific psychological ∗ Corresponding author. Fax: +44-29-2087-4937. E-mail address: snowden@cardiff.ac.uk (R.J. Snowden). 1 Present address: Department of Care of the Elderly, University of Bristol, Clinical Research Centre and Memory Disorders Clinic, The BRACE Centre, Blackberry Hill Hospital, Manor Road, Bristol BS16 2EW, UK. function [29,46]. Thus, for any particular task, we should es- tablish whether any function that we claim may be impaired in either normal ageing, or in DAT, is impaired beyond what may be predicted from a generalised slowing of function. 1.1. Endogenous and exogenous control of attention A popular method for assessing attentional selection is the spatial-cueing paradigm introduced by Posner [40]. In this paradigm, the participant responds to targets that can occur at one of two locations on either side of the fixation mark. Before the target appears, one of these locations is cued in some manner so that ‘attention’ may be focused at this location. It is commonly found that participants are better at detecting (as indexed by reaction time or sensitivity measurements) targets at this cued location in comparison to the uncued location. In this paradigm, the eyes are always fixated on the central mark, hence it is the covert movements of attention that are being assessed. Within this paradigm, there is a distinction made between the types of cue used. First, the participant can wilfully move their attention to a location because they believe that the tar- get is likely to occur at this location. Typically, this is done by a cue occurring at a central location (such as an arrow) 0028-3932/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII:S0028-3932(02)00057-X