Cognitively Stimulating Activities: Effects on Cognition across Four Studies with up to 21 Years of Longitudinal Data
Table 1
Octo-Twin participant characteristics.
Year of testing
Measure
Baseline
Year 2
Year 4
Year 6
Year 8
( )
( )
( )
( )
( )
Retention from previous testing (%)
82.2
76.8
75.9
70.8
Age [M (SD)]
83.3 (3.0)
85.2 (2.8)
86.9 (2.5)
88.8 (2.5)
90.7 (2.4)
Education [M (SD)]
7.2 (2.4)
7.3 (2.4)
7.3 (2.3)
7.2 (2.1)
7.2 (2.3)
Sex, female [ (%)]
369 (65)
304 (65)
235 (65)
195 (71)
144 (74)
Reasoning [M (SD)]
11.5 (7.1)
11.4 (7.2)
11.4 (7.1)
10.8 (7.2)
10.3 (7.3)
Memory [M (SD)]
9.6 (4.0)
9.4 (4.2)
9.2 (4.4)
9.2 (4.7)
9.0 (4.4)
Semantic knowledge [M (SD)]
28.1 (11.1)
28.6 (11.2)
27.5 (12.4)
26.7 (13.0)
26.2 (11.4)
Cognitive activity [M (SD)]
2.1 (1.7)
1.7 (1.6)
1.3 (1.4)
1.2 (1.4)
1.1 (1.3)
Activity change [M (SD)]
—
−0.3 (1.3)
−0.6 (1.3)
−0.8 (1.5)
−1.1 (1.6)
M: mean; SD: standard deviation. The theoretical ranges for each measure with a defined upper limit are as follows: reasoning = 0–42, Memory = 0–16, semantic knowledge = 0–44, and cognitive activity = 0–8.
