The influence of aging on spontaneous shifts of attention from external stimuli to the contents of consciousness.

In a series of studies using laboratory procedures and retrospective reports it has been established that with increasing age adults less frequently have unbidden task-unrelated image and thought intrusions (TUITs). TUITs--also referred to as daydreams--have been linked to the "current concerns" and "unfinished business" of the individual, and old adults have been shown to express fewer current concerns than young adults. It has also been hypothesized that selective loss of neurons in old age might interfere with thought production, resulting in fewer unbidden thoughts and spontaneous shifts of attention to them. In this article we examine the extent to which intraindividual change in the frequency of TUITs over 6 to 8 years is consistent with the decrease expected from the prior cross-sectional studies. In particular, we examine the frequency of daydreams based upon retrospective self-reports using the Daydreaming Frequency scale of the Imaginal Processes Inventory. The longitudinal sample consisted of 93 women and 169 men. Significant and equivalent decreases in Daydreaming Frequency scale values occurred at all ages. Longitudinal decreases were consistent with cross-sectional age differences. Thus, spontaneous shifts of attention to the contents of consciousness were seen to decrease over a 6 to 8 year interval within individuals--a result consistent with a within-individual change in conditions leading to spontaneous shifts.