Evaluating evidence for automaticity in frequency of occurrence judgments: a bias for bias?

Frequency of occurrence judgments were evaluated in young adults recovering from closed-head injuries, normal elderly, and young adult controls. Impaired performance was observed in both head-injured and elderly subjects, a result contrary to Hasher and Zacks' 1979 hypothesis that this information accumulates in memory via automatic processes which are unaffected by age, but supporting their conjecture that damage to the central nervous system would be sufficient to interfere with this function. The head-injured subject's performance on the frequency judgment task was correlated with effortful memory capacity as measured by several widely used memory tests. Whether the obtained group differences reflect differences in memory capacity or response criteria effects is discussed, and several methods of analyzing the data are compared.