Mohammed T. Abou-Saleh

Principles and Practice of Geriatric Psychiatry.Editors: Professor John R. M. Copeland, Dr Mohammed T. Abou-Saleh and Professor Dan G. BlazerCopyright & 2002 John Wiley & Sons LtdPrint ISBN 0-471-98197-4 Online ISBN 0-470-84641-028Computer Methods of Assessmentof Cognitive FunctionT. W. Robbins and Barbara J. SahakianDepartments of Experimental Psychology and Psychiatry, University of Cambridge, UKAlmost 20 years ago, the Royal College of Physicians recommendedthe use of automated testing procedures in assessing thedeficits of patients with dementia, particularly in the context ofclinical trials, because of their greater reliability and objectivity 1 .Since then, there have been several developments that havecapitalized on the explosion of computer technology and itsgeneral availability over the past decade, which have been thesubject of earlier reviews 2–5 .The advantages and disadvantages of computerized testing canreadily be summarized. Apart from the obvious objectivity andaccuracy of the measures and the standardization of theadministration of the tests themselves, there are potential gainsin patient compliance. Paper and pencil tests and clinicalassessment interviews are generally admitted not to be popularwith patients, perhaps because of their confrontational and formalnature. In our experience, computerized tests are also preferred byclinical assessors, who find that they have more time to focus onthe patient during testing, rather than upon the presentation ofthe test material and data recording. Well-designed computerizedtests that provide adequate feedback may provide some incentivefor patients to do well, thereby avoiding the difficult problems ofinterpretation provided by lack of motivation. On the other hand,there is often little to be gained from the mere administration ofstandard tests in a computerized format, except in terms of thelogging and storage of the data. Certainly it is infeasible todispense with the human assessor during computerized testing;indeed, it is vital that a trained individual is present during suchtesting. And requesting patients to interact with certain novel andcomplex forms of interface, such as keyboards and other complexmanipulanda, may serve only to confuse assessment by providingthe patients with an extra set of problems to master. In recentdevelopments, these problems have been circumvented, at least inpart, by the use of touch-sensitive screens, which require thepatient only to respond directly to the test stimuli themselveswithout imposing further demands by requiring them to dividetheir attention between a screen and a keyboard. It can also beargued that computerized assessment removes some of thecreative flexibility that an experienced clinical neuropsychologistcan bring to patient testing; however, this, too, can largely beavoided by the use of sufficiently flexible computerizedcontingencies.In this brief review, we will concentrate on some prominentbatteries that have been used for assessing cognitive functioningin the elderly. These batteries share some common principles,but also emphasize different aspects of design and administration.EARLY ATTEMPTS: A COMPUTERIZEDEVERYDAY MEMORY BATTERYCrook and his colleagues took into account clinical, theoreticaland psychometric considerations in designing their battery which,however, no longer appears to be generally available. However,their design historically represented a methodological advance inseveral respects and so we describe its main features below. Inparticular, they addressed the problem of ecological validity bysimulating everyday memory situations, such as memory for faces,the locations of objects, telephone numbers and shopping lists,narrative memory for a simulated news broadcast and topographicalmemory for routes 6–8 . This required at that time quiteadvanced computer technology, including the use of the touchsensitivescreen, laser disk and video recordings. Thus, forexample, one test involves viewing a live colour video recordingof people introducing themselves. The subject has to learn thenames that go with the faces and retain them over a 40 mindelay. Tests of immediate memory for telephone numbers areadministered with the subject actually dialling numbers on atelephone linked to the computer, having read a seven- (or 10-)digit number from the monitor screen. A reaction time task isconfigured to resemble the familiar situation of having to stopand start a car in relation to the colour of the prevailing trafficlights. The effects of certain theoretically interesting variables,such as degree of interference, can also be simulated, forexample, by having the subjects hear an ‘‘engaged’’ signal andthen asking them to redial the number.As well as achieving a clear face validity, the battery developedby Crook and his colleagues had a degree of theoretical orconstruct validity. Recognizing that many of the classical memorybatteries, such as the Wechsler Memory Scale 9 , in fact have acomplex factorial structure including dimensions that can belabelled Attention/Concentration and Orientation, as well asImmediate and General Memory, the battery contains a morecomprehensive examination of information-processing capacitythat includes, for example, explicit measures of speed of reaction.In addition, evidence for dissociable forms of memory process 10–11led to the inclusion of tests that probed different aspects ofmemory.Although unfortunately this battery no longer appears to bein general use, it was potentially useful in the diagnosis ofvarious age-related memory impairments, including thoseresulting from Alzheimer’s disease, and in the evaluation ofcandidate pharmacological treatments. It was mainly used tostudy the relationship between ageing and memory loss in aPrinciples and Practice of Geriatric Psychiatry, 2nd edn. Edited by J. R. M. Copeland, M. T. Abou-Saleh and D. G. Blazer&2002 John Wiley & Sons, Ltd