CDR Computerized Assessment System
The CDR Computerized Assessment System (CDR System) is a computerized battery of cognitive tests designed in the late 1970s by Professor Keith Wesnes at the University of Reading
University of Reading
The University of Reading is a university in the English town of Reading, Berkshire. The University was established in 1892 as University College, Reading and received its Royal Charter in 1926. It is based on several campuses in, and around, the town of Reading.The University has a long tradition...

 in Berkshire, England, for repeated testing in clinical trails. Task stimuli are presented in a laptop computer and participants respond via ‘YES’ and ‘NO’ buttons on a two-button response box, which records both the accuracy and reaction time.

The CDR System is a computer based cognitive testing tool, developed to assess both enhancement and impairment of human cognitive performance. The CDR System’s simplicity, sensitivity and specificity makes it acceptable to be used in clinical trials with either healthy subjects or diseased patient populations. The CDR System software is loaded onto laptop computers for testing in medical clinics. An internet version of The CDR System is available using keyboard commands to measure responses. Ancillary equipment is used for specific cognitive tests such as a postural stability (sway) meter, a critical flicker fusion device or joysticks for CDR’s tracking test.

The CDR System is a series of brief neuropsychological tests that assess major aspects of cognitive function known to be influenced by a wide variety of factors including trauma, fatigue, stress, nutrition, ageing, disease (both physical and mental), medicines and drugs. The standard battery of cognitive tests in The CDR System includes immediate/delayed word recall, word recognition, picture recognition, simple reaction time, digit vigilance, choice reaction time, numeric working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...

, and spatial working memory. Individual tests can be added to or removed from the battery to target specific cognitive domains. Examples of tests that can be added include measurements of executive function, mood states, social cognition
Social cognition
Social cognition is the encoding, storage, retrieval, and processing, in the brain, of information relating to conspecifics, or members of the same species. At one time social cognition referred specifically to an approach to social psychology in which these processes were studied according to the...

, motor function and postural stability. The standard battery of tests lasts 18 minutes.

The CDR System tasks have proven validity in definitively measuring cognitive function in a variety of domains including attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

, working memory
Working memory
Working memory has been defined as the system which actively holds information in the mind to do verbal and nonverbal tasks such as reasoning and comprehension, and to make it available for further information processing...

, episodic secondary memory, executive function, and motor skill
Motor skill
A motor skill is a learned sequence of movements that combine to produce a smooth, efficient action in order to master a particular task. The development of motor skill occurs in the motor cortex, the region of the cerebral cortex that controls voluntary muscle groups.- Development of motor skills...


In September, 2009, Cognitive Drug Research was acquired by United BioSource Corporation. UBC division Bracket continues to offer the CDR System for use in clinical research.

Referenced publications/abstracts

1. Effects of Rivastigmine on Cognitive Function in Dementia with Lewy Bodies: A Randomised Placebo-Controlled International Study Using the Cognitive Drug Research Computerised Assessment System I.G. McKeithb, R. Ferrarac, M. Emree, T. Del Serf, P.F. Spanod, A. Cicin-Saing, R. Anandh, R. Spiegelg]

2. P.M. Simpson, J.Surmonk (1991) The Cognitive Drug Research Computerized Assessment System for Demented Patients: A Validated Study

3. The cognitive drug research computerized assessment system in the evaluation of early dementia-is speed of the essence

4. Moon G, Manktelow TC (2002) Cognitive deficits in recently diagnosed untreated patients with Parkinson’s disease Journal of Psychopharmacology 16 (Suppl.): A31

5. Efficacy of rivastigmine in dementia with Lewy bodies: a randomised, double-blind, placebo-controlled international study The Lancet, Volume 356, Issue 9247, Pages 2031-2036 I.McKeith, T.Del Ser, P.Spano, M.Emre, K.Wesnes, R.Anand, A.Cicin-Sain, R.Ferrara, R.Spiegel

6. Macher J-P (2004) Modafinil reverses the marked attentional deficits produced by acute sleep deprivation in healthy volunteers. Journal of Psychopharmacology 18 (Suppl): A48

7. Cognitive Performance in Hypertensive and Normotensive Older Subjects

8. Neuman E, et al. (1994). Pharmacodynamic effects of a repeated oral administration of 4 dose levels of S 12024-2 in 36 elderly volunteers. Neurobiology of Aging 15: S100

9. Quantifying fluctuation in dementia with Lewy bodies, Alzheimer’s disease, and Vascular Dementia M. P. Walker, PhD, G. A. Ayre, PhD, J. L. Cummings, MD, I. G. McKeith, MD, J. T. O’Brien, DM and C. G. Ballard, MD

10. K, Mayleben D, Roth A, Corser B, Nandy P, Harris S, Perhach J (2004) Dose and time dependent discrimination of daytime sleepiness measured by multiple sleep latency tests (MSLT), Psychomotor performance tests (PPT) and Stanford Sleepiness Scale (SSS) after a single AM administration of a sedative hypnotic drug Sleep 27: A49

11. Simpson PM (1994) The construct validity of the cognitive drug research computerised assessment system. Journal of Psychopharmacology 8 (Suppl).: A20.

12. White, L, Simpson P, Herting R, Schwartz P (1994) Further evaluations of the criterion validity of the CDR computerised assessment system Journal of Psychopharmacology 8 (Suppl).: A21

13. Clinical Research (2000). The value of assessing cognitive function in drug development: Dialogues in Clinical Neuroscience 2: 183-202. (Lib: 86)

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.