Abstract

To study ageing of the central nervous system in our laboratory we usually use two prosaccade tasks—the standard one, and another designed by us, the rapid-target-walk (RTW) paradigm. In RTW task, target moves to the left or right by 10 or 20 degree and it doesn't returns back to the central position after each trial, as it is taking place in standard paradigm. Target's movements appear for the subject to be random, but in fact they form the predefined sequences counter-balancing potential effects of stimuli history. RTW task allows to shorten the duration of saccadic latency examination and is experienced by the subjects as being less boring than standard, providing also sustaining of attention on the task. Our previous experiences have shown that the increase of prosaccadic latency can be an effective marker of slowdowns that accompany nervous system ageing, however in detection of these changes an important role may play the capturing and effective holding of subjects attention on the task. We decided to examine sensitivity of Standard prosaccade task and rapid-target walk paradigm on subtle changes that appear in ageing nervous system within 1 year. We examined a group of 21 older adults aged 58–91 years two times after 1 year. Reaction times collected using RTW task were shorter as compared to latencies measured using Standard paradigm, what probably was the result of increased urgency or higher level of capturing subjects' attention on RTW paradigm. Statistical analysis for dependent variables revealed that mean and median of saccadic latency significantly differ after 1 year (in case of both: Standard and RTW task). Analysis of saccadic latency distributions for each subjects individually, revealed significant differences for five subjects (in case of both standard and RTW task).