436 Journal of Clinical and Experimental Neuropsychology, 27:436–448, 2005 Copyright © Taylor & Francis Ltd. ISSN: 1380-3395 DOI: 10.1080/13803390490520427 Journal of Clinical and Experimental Neuropsychology 274Taylor & FrancisTaylor and Francis 325 Chestnut StreetPhiladelphiaPA191061380-3395 NCEN Taylor & Francis Ltd. 36428 10.1080/13803390490520427 2005 1 35 R. Pignatti et al. Specific Impairments of Attention Specific Impairments of Selective Attention in Mild Alzheimer’s Disease RICCARDO PIGNATTI, 1, 2 MARCO RABUFFETTI, 3 EMILIA IMBORNONE, 1 FEDERICA MANTOVANI, 1 MARGHERITA ALBERONI, 1 ELISABETTA FARINA, 1 AND NICOLA CANAL 1 1 Neurorehabilitation Unit, Università di Milano, Fondazione Don Carlo Gnocchi IRCCS, Milan, Italy 2 Department of Psychology, Università degli Studi, Trieste, Italy 3 Centro di Bioingegneria FDG, Fondazione Don Carlo Gnocchi IRCCS, Milan, Italy The aim of the present study was to evaluate selective visual attention in subjects affected by Alzheimer’s Disease (AD), by means of a computerized spatial exploration test that adopts a Touch Screen (TS) interface, which has already proved able to char- acterize alternative strategies in performing search tasks. We assessed a group of 16 patients affected by mild to moderate AD, comparing them with 16 control subjects matched for age and education. In the experimental tasks the performance of the AD patients was worse than that of the normal elderly, both quantitatively (slower speeds) and qualitatively (poorer planning and higher number of omissions and persevera- tions). In the visual attention tasks there appeared to be no close connection between AD patients’ performance and increased Reaction Times (RT); this evidenced a specific role of non-elementary cognitive structures enclosed in a higher attentional domain, rather than a general decrease in the speed of basic cognitive processes. Our results are in line with specific AD literature: while psychomotor speed and lower attention levels (sensorimotor) are preferentially impaired in subcortical forms of dementia, the higher levels of selective and divided attention could be the first to dete- riorate and appear more markedly disrupted in the Alzheimer type of dementia. Introduction Selective attention is commonly defined as “the ability to react to specific stimuli and not to others” (James, 1890). The classic neurophysiological concept of arousal has been superseded by a more recent approach that pays selective attention to the role played by an administrator who assigns resources drawn from a general pool of limited capacity to particular cognitive operations (Kahneman, 1973). According to the Supervisory Attentional System (SAS) the- ory (Norman & Shallice, 1987) attention can be divided into many systems, hierarchically structured and governed by a Central Executive. The lower systems are simple but are able to perform even complex tasks quickly when such tasks have been learned well by the subjects. Received: 11 July 2003; accepted 1 December 2003. This study was supported by the research funding “Ricerca Finalizzata 2001” from the Italian Ministry of Health. The authors wish to thank Barbara Carey for the linguistic revision. Address correspondence to Riccardo Pignatti, C.so Brodolini, 26 – 27029 – Vigevano (PV) Italy E-mail: pignatti@virgilio.it