Abstract
Switching attention between two tasks takes longer time than complete simple task which has the same number of particulars. This effect is called a switch cost.
The aim of our study was to assess relation between psychomotor speed, working memory load and age using oral trail making test. Secondary we compared classical and oral version of trail making test (TMT).
Methodology: We included 137 healthy volunteers with mean age 45.5 - 18.9 years (min. 20, max. 80 years) to this study. We measured time to recite 12 words from each category (months, numbers) and recite 12 words during switch among 2, 3 and 4 routine sets (months, numbers, days of week, seasons).
Results: The time to recite 12 words was significantly longer after adding each new category ANOVA (p < 0.001). The time difference between 1 and 2 categories was 5s.
The switch cost increased about 4s with every new category. We observed significant correlation with age and TMT part A and B (Pearson's r = 0.47 resp. r = 0.52), 3-switch and 4-switch categories (r = 0.47 resp. r = 0.41).
The highest correlation was detected between Trail Making Test B and 4-switch categories (r = 0.61, p < 0.001). Discusion: We observed association between working memory demand and extension of time to finish oral trail making test.
Aging correlates with mental speed, and that could form base for impairment of working memory and other cognitive functions.