Download
predictors of cognitive functioning in midlife n.
Skip this Video
Loading SlideShow in 5 Seconds..
Predictors of Cognitive Functioning in Midlife PowerPoint Presentation
Download Presentation
Predictors of Cognitive Functioning in Midlife

Predictors of Cognitive Functioning in Midlife

111 Vues Download Presentation
Télécharger la présentation

Predictors of Cognitive Functioning in Midlife

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Predictors of Cognitive Functioning in Midlife S. L. Willis, K. W. Schaie, S. H. Hofer, & L. Hoffman The Pennsylvania State University, University Park, Pennsylvania/USA

  2. Aims of the Study: • To describe cohort differences in cognitive trajectories in midlife (Age Range: 43 - 63) • Inductive Reasoning • Word Fluency • Psychomotor Speed • To identify predictors of intercept and slope of cognitive trajectories • Time invariant: Education, Gender, Apo-E Allele 4 • Time varying: BMI (Body Mass Index)

  3. Sample • N = 888 males - females • Mean Age: • Mean Educational Level: • 5 Birth Cohorts studied at same midlife age range • Cohort 1910 (birth cohorts 1907 - 1913) • Cohort 1917 (birth cohorts 1914 - 1920) • Cohort 1924 (birth cohorts 1921 - 1927) • Cohort 1931 (birth cohorts 1928 - 1934) • Cohort 1938 (birth cohorts 1935 - 1941)

  4. Cognitive Outcomes • Inductive Reasoning - Ability to identify a pattern in a series of letters and to utilize the pattern in selecting the next letter in the series • Word Fluency - Number of words generated in 5 minutes • Psychomotor Speed - Speed in shifting cognitive sets in performing written task

  5. Analysis Plan (1) • Latent Growth Curve Models: • Linear • Quadratic • Unconditional Growth Models examining: Effects of age, cohort and retest • Age: Exact age at each of 3 occasions, centered at age 53 • Cohort represented by dummy codes, centered at 1963 cohort • Cohort differences examined for intercept & linear/quadratic slopes of age • Retest represented by dummy code; enter study at age 46 or age 53

  6. Analysis Plan (2) • Predictor Models • Time varying predictors were parameterized to express separate effects of between person and within person variation on level and change (slope) • Continuous predictors (BMI) • Between person - mean across 3 occasions • Within person - Deviation from person’s mean at each occasion

  7. Results for Reasoning: Cohort Differences in Score Level • Level of score at age 53: Overall positive cohort trend • No difference in score level at age 53 for the two earliest cohorts (1910, 1917) • More recent cohorts (1924, 1931, 1938) scored significantly higher at age 53, compared to the 1917 cohort • Limited Retest effects • Retest effects larger for 1910 cohort than for 1917 cohort

  8. Results for Reasoning:Cohort Differences in Trajectories(Piecewise models)

  9. Results for Reasoning:Predictors • Gender: Positive effect for women • Education: Positive effect on score level • Apo-E: No effect • BMI: No effect

  10. Results for Fluency: Cohort Differences in Score Level • Level of score at age 53: • No difference in score level at age 53 for the three earliest cohorts (1910, 1917, 1921) • Most recent cohort (1938) scored significantly higher at age 53, compared to the earlier cohorts • Limited Retest effects • Retest effects larger for 1910 and 1924 cohorts than for 1917 cohort

  11. Results for Fluency:Cohort Differences in Trajectories(Piecewise models)

  12. Results for Fluency:Predictors • Gender: Positive effect for women • Education: Positive effect on score level • Apo-E: No effect • BMI: Higher BMI in midlife related to lower Fluency score

  13. Results for Psychomotor Speed: Cohort Differences in Score Level • Level of score at age 53: Overall positive cohort trend: • Cohort 1910 score lower at age 53 than 1917 cohort • No difference between Cohorts 1917 and 1924 at age 53 • Most recent cohorts (1931,1938) scored significantly higher at age 53, compared to the earlier cohorts • Limited Retest effects • Retest effects larger for 1910 and 1924 cohorts than for 1917 cohort

  14. Results for Psychomotor Speed:Cohort Differences in Trajectories(Piecewise models)

  15. Results for Psychomotor Speed:Predictors • Gender: Positive effect for women • Education: Positive effect on score level • Apo-E: No effect • BMI: Higher BMI in midlife related to poorer Psychomotor Speed score