37 Hong Kong Med J ⎥ Volume 22 Number 1 (Supplement 2) ⎥ February 2016 ⎥ www.hkmj.org KEY MESSAGES 1. Te measures of prospective memory (ie the ability to remember what one has to do when a specifc event occurs in the future) and selective attention (ie the ability to maintain the task goal over time and resolve the confict between incongruent information) can discriminate between healthy older adults and those who are in the earliest stage of Alzheimer’s disease. 2. Prospective memory and selective attention performance declined as a function of Alzheimer’s disease severity, after taking into account age and number of years of education. 3. Te discriminative power of prospective memory and selective attention measures for early-stage Validation of selective attention and memory measures as early markers for Alzheimer’s disease CS Tse *, LCW Lam, DA Balota, GTY Leung, KT Hau, JF Chang Introduction It is important to diagnose people with Alzheimer’s disease at the earliest possible stage and discriminate these individuals from healthy older adults. Tis study aimed to develop prospective memory and selective attention measures to enable detection of individuals with the earliest stage of Alzheimer’s disease. Tree groups of community-dwelling older adults were recruited: healthy older adults (mean age, 75.06 years), older adults in the earliest stage of Alzheimer’s disease but not yet clinically diagnosed (mean age, 78.66 years), and older adults clinically diagnosed with Alzheimer’s disease (mean age, 80.20 years). Informed consent was obtained from each individual. Participants were screened for colour- blindness, depression, untreated hypertension, reversible dementia, and other disorders that could potentially produce cognitive impairment. Prospective memory and selective attention tasks were conducted using a laptop computer at place of residence or regional social centre. Prospective memory Many cognitive tasks tap older adults’ memory abilities but most focus almost exclusively on their retrospective memory, eg studying a list of unrelated words and then recalling them. In contrast, prospective memory, which refers to the ability to remember what one has to do in the future, 1 has received much less attention, despite its connection with activities of daily living. In a prospective memory task, older adults were instructed to spontaneously Hong Kong Med J 2016;22(Suppl 2):S37-9 HHSRF project number: 08090041 1 CS Tse, 2 LCW Lam, 3 DA Balota, 2 GTY Leung, 1 KT Hau, 1 JF Chang 1 Department of Educational Psychology, The Chinese University of Hong Kong 2 Department of Psychiatry, The Chinese University of Hong Kong 3 Department of Psychology and Neurology, Washington University in St. Louis, USA * Principal applicant and corresponding author: cstse@cuhk.edu.hk perform an intended action when a specifc event occurs, while engaging in a concurrent attention- demanding task. In each trial, they were asked to respond to a highlighted arrow by pressing the left or right key. Te top and bottom bars varied in colours (red, blue, yellow, or green) across trials (Figs 1a and 1b). In one-ffth of trials (24 out of 120 trials), the top and bottom bars were the same colour, and the participants were told to press an alternative key instead of judging the arrow direction. Tey were reminded to keep this instruction in mind because they would not be told again. Tat is, throughout the task older adults were not reminded with the prospective memory instruction. At the end, older adults were asked to recall what they had been asked to do during the task. Only those participants who were able to recall the prospective memory instruction were included in the following analyses. Tis retrospective memory report ensured that older adults’ failure to respond on the prospective memory trial was due to their inability to initiate the intended action at the right moment, rather than having forgotten the prospective memory instruction. Te task took about 12-15 minutes to complete. As the task does not involve verbal materials, it is suitable for Hong Kong older adults whose education level is generally low. Tis laboratory task may simulate daily-life situations, eg remembering to take a medicine before sleep or watching the news programme on TV. Older adults with Alzheimer’s disease often demonstrate prospective memory failure in their activities of daily living, which poses a great challenge for their caregivers. Hence, HEALTH AND HEALTH SERVICES RESEARCH FUND Alzheimer’s disease is comparable with that of other psychometric measures. Tese cognitive abilities should be incorporated into standard Alzheimer’s disease assessment.