Patterns of frontoparietal activation as a marker for unsuccessful visuospatial processing in healthy aging.

Visuospatial abilities are sensitive to age-related decline, although the neural basis for this decline (and its everyday behavioral correlates) is as yet poorly understood. fMRI was employed to examine age-related differences in patterns of functional activation that underlie changes in visuospatial processing. All participants completed a brief neuropsychological battery and also a figure ground task (FGT) assessing visuospatial processing while fMRI was recorded. Participants included 16 healthy older adults (OA; aged 69-82 years) and 16 healthy younger adults (YA; aged 20-35 years). We examined age-related differences in behavioral performance on the FGT in relation to patterns of fMRI activation. OA demonstrated reduced performance on the FGT task and showed increased activation of supramarginal parietal cortex as well as increased activation of frontal and temporal regions compared to their younger counterparts. Performance on the FGT related to increased supramarginal gyrus activity and increased medial prefrontal activity in OAs, but not YAs. Our results are consistent with an anterior-posterior compensation model. Successful FGT performance requires the perception and integration of multiple stimuli and thus it is plausible that healthy aging may be accompanied by changes in visuospatial processing that mimic a subtle form of dorsal simultanagnosia. Overall, decreased visuospatial processing in OA relates to an altered frontoparietal neurobiological signature that may contribute to the general phenomenon of increasingly fragmented execution of behavior associated with normal aging.

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Auditory Verbal Learning Test and the Visual Spatial Learning Test.

Although normative data sets for standardized neuropsychometric instruments frequently feature adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of education may be less closely associated with test performances than is overall intellectual functioning. In this last of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Rey Auditory Verbal Learning Test and the Visual Spatial Learning Test were found to be more strongly related to Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.150 to .395) than to education (rs=.060 to .236) for healthy older examinees between 56 and 99 years of age. Although AVLT-FSIQ correlations were greatest at moderate levels of intelligence, VSLT-FSIQ correlations consistently increased in strength as intelligence increased (cf. Dodrill, 19971999). Based on these results, we present tables of age- and IQ-adjusted percentile equivalents of Mayo age-adjusted AVLT index scores and MOANS age-adjusted AVLT and VSLT scaled scores for ten age ranges and either seven (AVLT) or five (VSLT) IQ ranges.

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Boston Naming Test, the MAE Token Test, and the Judgment of Line Orientation Test.

Although many extant normative data sets for standardized neuropsychometric instruments feature adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, several theoretical considerations suggest that years of formal education may be less closely related to test performances than is general intellectual functioning. In this first of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores on the Boston Naming Test, the MAE Token Test, and the Judgment of Line Orientation Test were indeed found to be more strongly associated with Mayo Age-adjusted WAIS-R Full Scale IQ scores (rs=.608, .473, and .502, respectively) than with education (rs=.310, .306, and .236, respectively) for healthy older examinees (56-99 years). Consistent with the remarks of Dodrill (19971999), these correlations generally decreased at higher levels of intelligence. The magnitude and pattern of such declines varied across the three tests, however, suggesting that IQ-test score associations must be empirically determined rather than assumed to be linear. Tables of Age- and IQ-Adjusted percentile equivalents of MOANS Age-adjusted BNT, Token Test, and JLO scaled scores are presented for eleven age ranges and seven IQ ranges. The article concludes with a discussion of factors that may underlie observed relations among age, intelligence, and neuropsychometric test performances.

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Wechsler Memory Scale--Revised.

Normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables. There are reasons to believe, however, that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, "years of formal education" may be less closely related to test performances than is general intellectual functioning. In this third of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted index and scaled scores for the Wechsler Memory Scale-Revised were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.271 to .631) than with education (rs=.089 to .310) for healthy older examinees between 56 and 99 years of age. These associations were strongest for Attention/Concentration and General Memory Index scores and, in general, for individuals with average intelligence (cf. Dodrill, 19971999). Tables of age- and IQ-adjusted percentile equivalents of Mayo age-adjusted WMS-R index scores and MOANS age-adjusted WMS-R subtest scaled scores are presented for eleven age ranges and seven IQ ranges.

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Trail-Making Test, the Stroop Test, and MAE Controlled Oral Word Association Test.

Although normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of formal education may be less closely related to test performances than is general intellectual functioning. In this second of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Trail-Making Test, the Stroop Color-Word Test, and the MAE Controlled Oral Word Associations Test were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.368 to .495) than with education (rs=.174 to .367) for healthy older examinees between 56 and 99 years of age. For the TMT and the COWAT, but not the Stroop, these associations became stronger as IQ increased (cf. Dodrill, 1997, 1999). Tables of age- and IQ-adjusted percentile equivalents of MOANS age-adjusted TMT, Stroop, and COWAT scores are presented for eleven age ranges and seven IQ ranges.