Abstract
The last-in first-out theory suggests that late-maturing brain regions are affected earlier in the life span than those maturing early. Maturation of the motor system and the frontal executive control system continues into early adulthood. Evidence further suggests that motor preparation, index by the contingent negative variation (CNV), matures relatively late in adolescence and is compromised in persons aged 68–83 years. With the present study we explored the progression of age-related changes in motor preparation control by contrasting behavioral and CNV effects in young (18–23), middle-aged (33–44) and older (61–72) persons using a modified response priming paradigm. All three groups showed the typical motor priming effect pattern with faster RTs in valid trials compared to invalid trials. RTs were significantly slower in the older than the middle-aged and young groups, with no significant difference in error rates. A significantly larger CNV validity effect was found for the young group compared to the older group. CNV topography shifted from parietal to more frontal regions with age. These data provide initial evidence for early changes in motor preparation control mechanisms and lend support for the last-in first-out hypothesis.