Effects of Gait and Cognitive Task Difficulty on Cognitive-Motor Interference in Aging

Table 1

Characteristics (mean, SD) of sample.

Variable	Young adults (𝑛=20)	Older adults (𝑛=15)	𝑃^†
Age	21.7 (1.6)	72.1 (5.2)	<.001
Female gender (number, %)	18 (90%)	12 (80%)	.418
Education (years)	15.3 (0.7)	12.4 (2.0)	<.001
MMSE^a (max. 30)	28.6 (1.1)	27.5 (2.2)	.080
Activities-specific balance confidence scale (max. 100)	95.8 (4.9)	85.9 (10.9)	.004
Digit symbol copy (time in seconds to complete)	57.4 (6.9)	84.1 (21.0)	.001
Digit symbol substitution (number correct in 90 seconds)	74.2 (9.1)	46.1 (13.2)	<.001
Stroop color-word interference^b	24.1 (7.5)	35.8 (13.0)	.005
Comprehensive trail-making test interference^c (seconds)	13.8 (9.7)	35.1 (24.8)	.006
TUG (seconds)	7.4 (0.7)	9.6 (2.4)	.003

^†𝑡-test for independent samples.
Abbreviations: MMSE: Mini Mental State Examination; TUG: Timed Up and Go test; 𝑃 value is for 𝑡-test comparing young and older adults.
^aMMSE measures global cognitive function; Digit symbol modalities test measures speed of processing and attention; Stroop and Trail Making Tests measure executive function; TUG measures balance during functional performance.
^bStroop interference score calculated as difference in number correct between baseline condition and interference condition.
^cTrail-making test interference score calculated as difference in time (seconds) between time to complete Trail 5 and Trail 1.