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Asymmetrical Transfer: An Inherent Weakness of Repeated-Measure Drug Experiments

Published online by Cambridge University Press:  29 January 2018

Keith Millar
Keith Millar*
Affiliation:
University Department of Psychiatry, University Hospital and Medical School, Clifton Boulevard, Nottingham NG7 2UH
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Summary

When subjects act as their own controls in drug experiments there is a risk of asymmetrical transfer between treatment conditions, with the result that treatment effects are determined largely by order of administration. In such cases the effect of a drug may be reduced or exaggerated, and prior treatment with a drug may affect placebo conditions. Asymmetrical transfer is probably much more common than is generally realized. Suggested causes include inadequate wash-out between treatments, state-dependent learning, adoption of learning strategies, and practice effects. The problem is illustrated by the re-analysis of a paper on the effects of benzhexol on memory, published recently in this journal (Potamianos and Kellet, 1982). The advantages of separate-group experimental design are reconsidered.

Type
Research Article
Information
The British Journal of Psychiatry , Volume 143 , Issue 5 , November 1983 , pp. 480 - 486
Copyright
Copyright © 1983 The Royal College of Psychiatrists 

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References

Baddeley, A. D. (1976) The Psychology of Memory. New York: Harper and Row.Google Scholar
File, S. E. & Lister, R. G. (1982) Do lorazepam-induced deficits in learning result from impaired rehearsal, reduced motivation or increased sedation? British Journal of Clinical Pharmacology, 14, 545–50.Google Scholar
Gore, S. M., Jones, I. G. & Rytter, E. C. (1977) Measures of statistical methods: critical assessment of articles in B.M.J. from January to March 1976. British Medical Journal, i, 85–7.Google Scholar
Hamilton, P. & Hockey, G. R. J. (1970) Recency/primacy ratio: a short test of task orientation. Psychonomic Science, 21, 253–4.Google Scholar
Hills, M. & Armitage, P. (1979) The two-period cross-over clinical trial. British Journal of Clinical Pharmacology, 8, 7–20.Google Scholar
Jones, D. M., Lewis, M. J. & Spriggs, T. L. B. (1978) The effects of low doses of diazepam on human performance in group administered tasks. British Journal of Clinical Pharmacology, 6, 333–7.Google Scholar
Ley, P., Jain, V. K., Swinson, R. P., Eaves, D., Bradshaw, P. W., Kincey, J. A., Crowder, R. & Abbiss, S. (1972) A state-dependent learning effect produced by amylobarbitone sodium. British Journal of Psychiatry, 120, 511–15.CrossRefGoogle ScholarPubMed
Millar, K. & Standen, P. J. (1982) Differences in performance impairment due to brompheniramine maleate as a function of the sustained release system. British Journal of Clinical Pharmacology, 14, 49–55.Google Scholar
Millar, K. & Walder, C. P. (1980) A statistical error in Wood and Cook's (1979) ‘Attentional deficit in the siblings of schizophrenics’. Psychological Medicine, 10, 381–2.CrossRefGoogle ScholarPubMed
Millar, K. & Wilkinson, R. T. (1981) The effects upon vigilance and reaction speed of the addition of ephedrine hydrochloride to chlorpheniramine maleate. European Journal of Clinical Pharmacology, 20, 35–7.Google Scholar
Pocock, S. J. (1980) The role of statistics in medical research. British Journal of Psychiatry, 137, 188–90.Google Scholar
Potamianos, G. & Kellett, J. M. (1982) Anti-cholinergic drugs and memory: the effects of benzhexol on memory in a group of geriatric patients. British Journal of Psychiatry, 140, 470–2.Google Scholar
Poulton, E. C. (1973) Unwanted range effects from using balanced experimental designs. Psychological Bulletin, 80, 113–21.Google Scholar
Poulton, E. C. (1975) Range effects in experiments on people. American Journal of Psychology, 88, 3–32.Google Scholar
Poulton, E. C. (1982) Influential companions: effects of one strategy on another in the within-subject designs of cognitive psychology. Psychology Bulletin, 91, 673–90.Google Scholar
Poulton, E. C. & Edwards, R. S. (1979) Asymmetric transfer in within-subjects experiments on stress interaction. Ergonomics, 22, 945–61.Google Scholar
Poulton, E. C. & Freeman, P. R. (1966) Unwanted asymmetrical transfer effects with balanced experimental designs. Psychological Bulletin, 66, 1–8.Google Scholar
White, S. J. (1979) Statistical errors in papers in the British Journal of Psychiatry. British Journal of Psychiatry, 135, 336–42.Google Scholar
Wilkinson, R. T. (1969) Some factors influencing the effect of environmental stressors upon performance. Psychological Bulletin, 72, 260–72.Google Scholar
Winer, B. J. (1970) Statistical Principles in Experimental Design, p. 301. New York: McGraw Hill.Google Scholar
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