Cover legend: Financial decision making can be especially risky for older investors, who have relatively little time left to recover from mistakes. A new study reveals that age-related mistakes in financial risk taking are mediated by a novel measure of neural signal variability in the striatum. For more information, see the article by Samanez-Larkin et al. in this issue (pages 1426–1434). Illustration © Janusz Kapusta / Corbis