Knowledge of neurocognitive performance patterns of normal, healthy individuals is necessary, as clinicians may not always take into account normal intra-individual variability, demonstrated here in a sample of 20 healthy individuals with particularly high educational achievement (i.e., holding doctorate degrees). The data indicate that neurocognitive abilities are not equally distributed within a given individual. Some participants in the sample achieved some test scores at the intellectually disabled to borderline range but also some scores in the high average to superior range. The practice of deductive reasoning in clinical neuropsychology may be prone to false positive conclusions about neurocognitive functioning where base rates of neurocognitive impairments are low and pre-existing educational achievements are high.
Get full access to this article
View all access options for this article.
References
1.
BentonA. L.SivanA. B.HamsherK.VarneyN. R.SpreenO. (1994) Contributions to neuropsychological assessment. A clinical manual. (2nded.) New York: Oxford Univer. Press.
2.
BinderL. M.IversonG. L.BrooksB. L. (2009) To err is human: “abnormal” neuropsychological scores and variability are common in healthy adults. Archives of Clinical Neuropsychology, 24, 31–46.
3.
BinderL. M.RohlingM. L.LarrabeeG. J. (1997) A review of mild head trauma: 1. Meta-analytical review of neuropsychological studies. Journal of Clinical and Experimental Neuropsychology, 19, 421–431.
4.
BornsteinR. A. (1985) Normative data on selected neuropsychological measures from a nonclinical sample. Journal of Clinical Psychology, 41, 651–658.
5.
Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, Social Sciences and Humanities Research Council of Canada. (1998) Tri-council policy statement: ethical conduct for research involving humans. (with 2000, 2002, and 2005 amendments).
6.
ChristensenH.MackinnonA.KortenA.JormA.HendersonA.JacombP.RodgersB. (1999) An analysis of diversity in the cognitive performance of elderly community dwellers: individual differences in change scores as a function of age. Psychological Aging, 14, 365–379.
7.
ChristiansonM. K.LeathemJ. M. (2004) Development and standardisation of the computerised finger tapping test: comparison with other finger tapping instruments. New Zealand Journal of Psychology, 33(2), 44–49.
8.
DelisD. C.KramerJ. H.KaplanE.OberB. (2000) California Verbal Learning Test–second edition (CVLT–II). San Antonio, TX: The Psychological Corporation.
9.
Diaz-AsperC. M.SchretlenD. J.PearlsonG. D. (2004) How well does IQ predict neuropsychological test performance in normal adults. Journal of the International Neuropsychological Society, 10, 82–90.
10.
EconomouA. (2009) Memory score discrepancies by healthy middle-aged and older individuals: the contributions of age and education. Journal of the International Neuropsychological Society, 15, 963–972.
11.
GyurkeJ. S.PrifiteraA.SharpS. A. (1991) Frequency of verbal and performance IQ discrepancies on the WPPSI–R at various levels of ability. Journal of Psychoeducational Assessment, 9(3), 230–239.
12.
HawkinsK. A.TulskyD. S. (2001) The influence of IQ stratification on WAIS–III/ WMS–III FSIQ–general memory index discrepancy base-rates in the standardization sample. Journal of the International Neuropsychological Society, 7, 875–880.
13.
HeatonR. K.MillerS. W.TaylorM. J.GrantI. (2004) Revised comprehensive norms for an expanded Halstead-Reitan Battery: demographically adjusted neuropsychological norms for African American and Caucasian adults. Lutz, FL: Psychological Assessment Resources.
14.
HeatonR. K.RyanL.GrantI.MatthewsG. G. (1996) Demographic influences on neuropsychological test performance. In GrantI.AdamsK. (Eds.), Neuropsychological assessment of neuropsychiatric disorders. (2nd ed.) New York: Oxford Univer. Press. Pp. 141–163.
15.
HultschD.MacDonaldS.HunterM.Levy-BenchetonJ.StraussE. (2000) Intraindividual variability in cognitive performance in older adults: comparison of adults with mild dementia, adults with arthritis, and healthy adults. Neuropsychology, 14, 588–598.
16.
KaufmanA. S. (1976) Verbal-performance IQ discrepancies on the WISC–R. Journal of Consulting and Clinical Psychology, 44, 739–744.
LongC. J.CollinsL. F. (1997) Ecological validity and forensic neuropsychological assessment. In McCaffreyR. J.WilliamsA. D.FisherJ. M.LaingL. C. (Eds.), The practice of forensic neuropsychology: meeting challenges in the courtroom. New York: Plenum Press. Pp. 153–164.
19.
MatarazzoJ. D.DanielM. H.PrifiteraA.HermanD. O. (1988) Inter-subtest scatter in the WAIS–R standardization sample. Journal of Clinical Psychology, 44(6), 940–950.
20.
MatarazzoJ. D.HermanD. O. (1984) Base rate data for the WAIS–R: test-retest-stability and VIQ-PIQ differences. Journal of Clinical Neuropsychology, 6(4), 351–366.
21.
MatarazzoJ. D.PrifiteraA. (1989) Subtest scatter and premorbid intelligence: lessons from the WAIS–R standardization sample. Psychological Assessment, 1(3), 186–191.
22.
McLeanJ. E.KaufmanA. S.ReynoldsC. R. (1989) Base rates of WAIS–R subtest scatter as a guide for clinical and neuropsychological assessment. Journal of Clinical Psychology, 45, 919–926.
23.
MeyersJ. E.MeyersK. E. (1995) Rey Complex Figure Test and recognition trial: professional manual. Odessa, FL: Psychological Assessment Resources.
24.
MitrushinaM.BooneK. B.RazaniJ.D'EliaL. F. (2005) Handbook of normative data for neuropsychological assessment. (2nd ed.) New York: Oxford Univer. Press.
25.
PalmerB. W.BooneK. B.LesserI. M.WohlM. A. (1998) Base rates of “impaired” neuropsychological test performance among healthy older adults. Archives of Clinical Neuropsychology, 13, 503–511.
26.
RabinL. A.BorgosM. J.SaykinA. J. (2008) A survey of neuropsychologist's practices and perspectives regarding the assessment of judgment ability. Applied Neuropsychology, 15(4), 264–273.
27.
RamN.RabbitP.StolleryB.NesselroadeJ. R. (2005) Cognitive performance inconsistency: intraindividual change and variability. Psychology and Aging, 20, 623–633.
28.
SchretlenD. J.MunroC. A.AnthonyJ. C.PearlsonG. D. (2003) Examining the range of normal intraindividual variability in neuropsychological test performance. Journal of the International Neuropsychological Society, 9, 864–870.
29.
SchretlenD. J.TestaS. M.WinickiJ. M.PearlsonG. D.GordonB. (2008) Frequency and bases of abnormal performance by healthy adults on neuropsychological functioning. Journal of the International Neuropsychological Society, 14, 436–445.
30.
SilversteinA. B. (1987) Accuracy of estimates of premorbid intelligence based on demographic variables. Journal of Clinical Psychology, 43, 493–495.
31.
StraussE.ShermanE. M. S.SpreenO. (2006) A compendium of neuropsychological tests: administration, norms, and commentary. (3rd ed.) New York: Oxford Univer. Press.
