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Intra-individual measures of association in neuropsychology: Inferential methods for comparing a single case with a control or normative sample

Published online by Cambridge University Press:  12 February 2004

JOHN R. CRAWFORD
Affiliation:
Department of Psychology, King's College, University of Aberdeen, Aberdeen, UK
PAUL H. GARTHWAITE
Affiliation:
Department of Statistics, The Open University, UK
DAVID C. HOWELL
Affiliation:
Department of Psychology, University of Vermont, Burlington
ANNALENA VENNERI
Affiliation:
Department of Psychology, King's College, University of Aberdeen, Aberdeen, UK

Abstract

Performance on some neuropsychological tests is best expressed as an intra-individual measure of association (such as a parametric or non-parametric correlation coefficient or the slope of a regression line). Examples of the use of intra-individual measures of association (IIMAs) include the quantification of performance on tests designed to assess temporal order memory or the accuracy of time estimation. The present paper presents methods for comparing a patient's performance with a control or normative sample when performance is expressed as an IIMA. The methods test if there is a significant difference between a patient's IIMA and those obtained from controls, yield an estimate of the abnormality of the patient's IIMA, and provide confidence limits on the level of abnormality. The methods can be used with normative or control samples of any size and will therefore be of particular relevance to single-case researchers. A method for comparing the difference between a patient's scores on two measures with the differences observed in controls is also described (one or both measures can be IIMAs). All the methods require only summary statistics (rather than the raw data from the normative or control sample); it is hoped that this feature will encourage the development of norms for tasks that use IIMAs to quantify performance. Worked examples of the statistical methods are provided using data from a clinical case and controls. A computer program (for PCs) that implements the methods is described and made available. (JINS, 2003, 9, 989–1000.)

Type
Research Article
Copyright
© 2003 The International Neuropsychological Society

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References

REFERENCES

American Psychological Association. (2001). Publication manual of the American Psychological Association (5th ed.). Washington, DC: Author.
Capitani, E. (1997). Normative data and neuropsychological assessment. Common problems in clinical practice and research. Neuropsychological Rehabilitation, 7, 295309.Google Scholar
Caramazza, A. & McCloskey, M. (1988). The case for single-patient studies. Cognitive Neuropsychology, 5, 517528.Google Scholar
Carey, D.P. (1996). Visuomotor sensitivity for shape and orientation in a patient with visual form agnosia. Neuropsychologia, 34, 329337.Google Scholar
Carey, D.P., Dijkerman, H.C., & Milner, A.D. (1998). Perception and action in depth. Consciousness and Cognition, 7, 438453.Google Scholar
Code, C., Wallesch, C., Joanette, Y., & Lecours, A.R. (Eds.). (1996). Classic cases in neuropsychology. Hove, UK: Psychology Press.
Crawford, J., Bryan, J., Luszcz, M., Obonsawin, M., & Stewart, L. (2000). The executive decline hypothesis of cognitive ageing: Do executive deficits qualify as differential deficits and do they mediate age-related memory decline? Aging, Neuropsychology and Cognition, 7, 931.Google Scholar
Crawford, J.R. (1996). Assessment. In J.G. Beaumont, P.M. Kenealy, & M.J. Rogers (Eds.), The Blackwell dictionary of neuropsychology (pp. 108116). London: Blackwell.
Crawford, J.R. (2003). Psychometric foundations of neuropsychological assessment. In L.H. Goldstein & J. McNeil (Eds.), Clinical neuropsychology: A practical guide to assessment and management for clinicians. Chichester, UK: Wiley.
Crawford, J.R. & Allan, K.M. (1996). WAIS–R subtest scatter: Base rate data from a healthy UK sample. British Journal of Clinical Psychology, 35, 235247.Google Scholar
Crawford, J.R. & Garthwaite, P.H. (2002). Investigation of the single case in neuropsychology: Confidence limits on the abnormality of test scores and test score differences. Neuropsychologia, 40, 11961208.Google Scholar
Crawford, J.R. & Garthwaite, P.H. (2003). Statistical methods for single-case research: Comparing the slope of a patient's regression line with those of a control sample. Cortex (in press).Google Scholar
Crawford, J.R., Garthwaite, P.H., & Gray, C.D. (2003). Wanted: Fully operational definitions of dissociations in single-case studies. Cortex, 39, 357370.Google Scholar
Crawford, J.R. & Howell, D.C. (1998). Comparing an individual's test score against norms derived from small samples. Clinical Neuropsychologist, 12, 482486.Google Scholar
Crawford, J.R., Howell, D.C., & Garthwaite, P.H. (1998). Payne and Jones revisited: Estimating the abnormality of test score differences using a modified paired samples t-test. Journal of Clinical and Experimental Neuropsychology, 20, 898905.Google Scholar
Daly, F., Hand, D.J., Jones, M.C., Lunn, A.D., & McConway, K.J. (1995). Elements of statistics. Wokingham, UK: Addison-Wesley.
Ellis, A.W. & Young, A.W. (1996). Human cognitive neuropsychology: A textbook with readings. Hove, UK: Psychology Press.
Fieller, E.C., Hartley, H.O., & Pearson, E.S. (1957). Testa for rank correlation coefficients I. Biometrika, 48, 2940.Google Scholar
Fieller, E.C. & Pearson, E.S. (1961). Testa for rank correlation coefficients II. Biometrika, 48, 2940.Google Scholar
Gardner, M.J. & Altman, D.G. (1989). Statistics with confidence—confidence intervals and statistical guidelines. London: British Medical Journal.
Heaton, R.K. (1981). Wisconsin Card Sorting Test manual. Odessa, FL: Psychological Assessment Resources, Inc.
Heindel, W.C., Salmon, D.P., & Butters, N. (1991). The biasing of weight judgments in Alzheimers and Huntington's disease—a priming or programming phenomenon. Journal of Clinical and Experimental Neuropsychology, 13, 189203.Google Scholar
Howell, D.C. (1997). Statistical methods for psychology (4th ed.). Belmont, CA: Duxbury Press.
Howell, D.C. (2002). Statistical methods for psychology (5th ed.). Belmont, CA: Duxbury Press.
Humphreys, G.W. (Ed.). (1999). Case studies in the neuropsychology of vision. Hove, UK: Psychology Press.
Jeannerod, M. (1984). The timing of natural prehension movements. Journal of Motor Behavior, 16, 235254.Google Scholar
Jones, L.A. (1986). Perception of force and weight: Theory and research. Psychological Bulletin, 100, 2942.Google Scholar
Kraemer, H.C. (1974). The non-null distribution of the Spearman rank correlation coefficient. Journal of the American Statistical Society, 69, 114117.Google Scholar
Lafargue, G. & Sirigu, A. (2002). Sensation of effort is altered in Huntington's disease. Neuropsychologia, 40, 16541661.Google Scholar
Ley, P. (1972). Quantitative aspects of psychological assessment. London: Duckworth.
Mayes, A.R., Isaac, C.L., Holdstock, J.S., Hunkin, N.M., Montaldi, D., Downes, J.J., MacDonald, C., Cezayirli, E., & Roberts, J.N. (2001). Memory for single items, word pairs, and temporal order of different kinds in a patient with selective hippocampal lesions. Cognitive Neuropsychology, 18, 97123.Google Scholar
McCarthy, R.A. & Warrington, E.K. (1990). Cognitive neuropsychology: A clinical introduction. San Diego, CA: Academic Press.
Milner, A.D., Perret, D.I., Johnston, R.S., Benson, P.J., Jordan, T.R., Heeley, D.W., Bettucci, D., Mortara, F., Mutani, R., Terazzi, E., & Davidson, D.L.W. (1991). Perception and action in visual form agnosia. Brain, 114, 405428.Google Scholar
Nichelli, P., Venneri, A., Molinari, M., Tavani, F., & Grafman, J. (1993). Precision and accuracy of subjective time estimation in different memory disorders. Cognitive Brain Research, 1, 8793.CrossRefGoogle Scholar
Richards, W. (1973). Time production by H.M. Acta Psychologica, 37, 279282.Google Scholar
Shallice, T. (1979). Case study approach in neuropsychological research. Journal of Clinical Neuropsychology, 3, 183211.Google Scholar
Shallice, T. (1988). From neuropsychology to mental structure. Cambridge, UK: Cambridge University Press.
Sherwin, I. & Effron, R. (1980). Temporal ordering deficits following anterior temporal lobectomy. Brain and Language, 11, 195203.Google Scholar
Shimamura, A.P., Janowsky, J.S., & Squire, L.R. (1990). Memory for the temporal order of events in patients with frontal lobe lesions and amnesic patients. Neuropsychologia, 28, 803813.Google Scholar
Shimamura, A.P., Janowsky, J.S., & Squire, L.R. (1991). What is the role of frontal lobe damage in memory disorders? In H.S. Levin, H.M. Eisenberg, & A.L. Benton (Eds.), Frontal lobe function and dysfunction (pp. 173195). New York: Oxford University Press.
Sokal, R.R. & Rohlf, J.F. (1995). Biometry (3rd ed.). San Francisco: W.H. Freeman.
Steinke, W.R., Cuddy, L.L., & Holden, R.R. (1997). Dissociation of musical tonality and pitch memory from nonmusical cognitive abilities. Canadian Journal of Experimental Psychology, 51, 316334.Google Scholar
Steinke, W.R., Cuddy, L.L., & Jakobson, L.S. (2001). Dissociations among functional subsystems governing melody recognition after right-hemisphere damage. Cognitive Neuropsychology, 18, 411437.Google Scholar
Tabachnick, B.G. & Fidell, L.S. (1996). Using multivariate statistics (3rd ed.). New York: Harper Collins.
Turnbull, O.H., Carey, D.P., & McCarthy, R.A. (1997). The neuropsychology of object constancy. Journal of the International Neuropsychological Society, 3, 288298.Google Scholar
Turnbull, O.H., Della Sala, S., & Beschin, N. (2002). Agnosia for object orientation: Naming and mental rotation evidence. Neurocase, 8, 296305.Google Scholar
Venneri, A., Pestell, S., Gray, C.D., Della Sala, S., & Nichelli, P. (1998). Memory, attention, and estimation of time. Brain and Cognition, 37, 169172.Google Scholar
Wechsler, D. (1981). Manual for the Wechsler Adult Intelligence Scale–Revised. New York: The Psychological Corporation.
Willmes, K. (1985). An approach to analyzing a single subject's scores obtained in a standardized test with application to the Aachen Aphasia Test (AAT). Journal of Clinical and Experimental Neuropsychology, 7, 331352.Google Scholar
Zar, J.H. (1996). Biostatistical analysis (3rd ed.). London: Prentice-Hall.