Predicting Impending Death: Inconsistency in Speed is a Selective and Early Marker




Hultsch, D.F.
Dixon, R.A.
MacDonald, Stuart W.S.

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Psychology and Aging


Among older adults, deficits in both level and variability of speeded performance are linked to neurological impairment. This study examined whether and when speed (rate), speed (inconsistency), and traditional accuracy-based markers of cognitive performance foreshadow terminal decline and impending death. Victoria Longitudinal Study data spanning 12 years (5 waves) of measurement were assembled for 707 adults aged 59 to 95 years. Whereas 442 survivors completed all waves and relevant measures, 265 decedents participated on at least one occasion and subsequently died. Four main results were observed. First, Cox regressions evaluating the three cognitive predictors of mortality replicated previous results for cognitive accuracy predictors. Second, level (rate) of speeded performance predicted survival independent of demographic indicators, cardiovascular health, and cognitive performance level. Third, inconsistency in speed predicted survival independent of all influences combined. Fourth, follow-up random-effects models revealed increases in inconsistency in speed per year closer to death, with advancing age further moderating the accelerated growth. Hierarchical prediction patterns support the view that inconsistency in speed is an early behavioral marker of neurological dysfunction associated with impending death.



cognitive aging, inconsistency, neurocognitive resources, speed, terminal decline, mortality


MacDonald, S.W.S., Hultsch, D.F., & Dixon, R.A. (2008). Predicting Impending Death: Inconsistency in Speed is a Selective and Early Marker. Psychology and Aging, 23(3), 595-607.