Trail Making Test performance in a community-based sample of healthy very old adults: effects of age on completion time, but not on accuracy.

A population-based sample of healthy old adults ranging from 76 to 93 years of age (n=94) was examined in the Trail Making Test (TMT), and in tests assessing motor functions of the hands (the dynamic and optic-spatial organization of the motor act). Results indicated no age-related differences in TMT accuracy, although the time required to complete the test increased with increasing age. Similar patterns of results were observed for TMT-A and TMT-B. There were no age-related differences in the tests of hand-motor functioning, and subjects were carefully screened on visual and auditory capacity, hence making it unlikely that motor and sensory factors contributed to the results obtained. A test of visuo-spatial skill (Block Design Test) was marginally related to performance on TMT-B, whereas sex, education, a marker of global cognitive status (the Mini-Mental State Exam), and tests of primary memory (digit dpan forward and digit span backward) made no contribution to TMT performance. Several biological variables (e.g. vitamin B12, albumin, blood pressure) were also unrelated to TMT performance, although a positive relationship between thyroid stimulating hormone and TMT-B performance was documented. It was suggested that the influence of age on TMT speed may reflect age-related deficits in a variety of task-relevant skills, including perceptual speed, attentional functions (e.g. vigilance, concentration, visual scanning), and visuo-spatial ability.