title: Getting Past "g": testing a new model of dementing processes in persons without dementia.
abstract: The cognitive correlates of functional status are essential to dementia case-finding. The authors have used structural-equation models to explicitly distinguish dementia-relevant variance in cognitive task performance (i.e., δ) from the variance that is unrelated to a dementing process (i.e., g'). Together, g' and δ comprise Spearman's "g." Although δ represents only a small fraction of the total variance in cognitive task performance, it is more strongly associated with dementia severity than is g'. In this analysis, the authors test whether δ can predict future cognitive decline in persons clinically without dementia at baseline. These results have implications for the clinical assessment of dementia and suggest that functional status should assume a more important role.
authors.affiliation: Department of Psychiatry, the University of Texas Health Science Center, San Antonio, TX, USA. royall@uthscsa.edu
authors.forename: Donald R
authors.initials: DR
authors.lastname: Royall
authors.forename: Raymond F
authors.initials: RF
authors.lastname: Palmer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001245:Association Learning / Q000502:physiology*; D003072:Cognition Disorders / Q000503:physiopathology* / Q000523:psychology; D015331:Cohort Studies; D003704:Dementia / Q000503:physiopathology*; D056344:Executive Function; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D015233:Models, Statistical; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D014705:Verbal Behavior / Q000502:physiology*