Cognition and daily activities in a general population sample aged +55

ABSTRACT

Objective: We tested the association of individual cognitive domains measured with the Mini-Mental State Examination (MMSE) and disability.

Method: Cross-sectional study in a population-based cohort aged ≥55 years (n = 4,803). Sample was divided into two groups: individuals with cognition within the normal range (CNR) (n = 4,057) and those with cognitive impairment (CI) (n = 746). Main outcome measures: The MMSE, the Katz Index (Basic Activities of Daily Living, bADL), the Lawton and Brody Scale (Instrumental Activities of Daily Living, iADL), and the Geriatric Mental State (GMS-AGECAT).

Results: MMSE-orientation was associated with disability in bADL, iADL and a decrease in social participation, regardless of cognitive status. MMSE-attention was associated with disability in iADL, but only in CNR. MMSE-language was associated with disability in bADL, iADL and with reduced social participation, but only in CI. Conclusions: The associations observed between disability and orientation may have clinical and public health implications.     

Hemispheric activation increases positive manifold for lateralized cognitive tasks: an extension of Stankov's hypothesis

Stankov (1983a, Journal of Educational Psychology, 75, 471-490) suggests that the dual task paradigm, requiring the division of attention, increases positive manifold (i.e., positive intercorrelations) for cognitive tasks relative to the single task paradigm. Two dual task studies are reported. Unimanual finger-tapping served as the primary task and the short-term retention (20 sec) of digit or spatial-location sequences served as the secondary tasks. When both tasks were lateralized to the same hemisphere (digits and right-hand tapping or spatial locations and left-hand tapping), highest memory task intercorrelations (Experiment 1) and better retention of sequences (Experiments 1 and 2) resulted. Left-hand tapping produced more leftward looking and right-hand tapping more rightward looking (Experiment 2). Overflow from lateralized finger-tapping may shift the gradient of attentional activation toward the contralateral hemisphere, producing the homolateral gaze direction, the increase in positive manifold, and the better retention of sequences lateralized to that hemisphere.