Evidence suggests that subliminal stimuli can influence ostensibly volitional, executive processes but it is unclear whether this is highly task-specific. To address this we used a set-switching task. Volunteers saw a word pair and reported either if both words had the same number of syllables or if both were concrete. Task selection was random and instructed by a hexagon/triangle preceding the words. A subliminally-presented square or diamond reliably preceded each of these consciously perceived instruction-shapes. Significant congruency effects were observed in a subsequent Test Phase in which primes no longer reliably predicted the task (and in which high/low tones now served as conscious instructions). The Generalization Phase required novel phonological (rhyme) or semantic (category) judgments. Remarkably, unconscious priming congruency effects carried over in those participants who had shown priming in the Test Phase, the degree correlating across the two conditions. In a final phase of the study, participants were asked to discriminate between the two originally presented prime shapes. Those participants whose discriminations were more accurate showed reduced priming relative to participants with less accurate discriminations. The results suggest that, rather than being highly task specific, priming can operate at the level of a generalizable process and that greater awareness of primes may lessen their impact on behavior.

Background: Executive function deficits are commonly observed in many clinical populations, highlighting the importance of appropriate diagnostic tools to screen for these deficits. Most neuropsychological tests of executive function, however, are time-consuming and difficult to administer in the case of moderate to severe cognitive decline. The aim of the present study was to examine whether the Key Search Test, a short and easy to administer test, is a useful indicator of executive function deficits in a study sample with a diagnosis of cognitive impairment. Methods: Participants consisted of elderly people visiting the memory clinic at the department of geriatrics of a university medical center (n = 140) and of elderly controls (n = 37). Next to the Key Search Test, other executive function tests and a memory test were administered. Results: Low to moderate correlations were found between the Key Search Test and other executive function tests. Furthermore, although the Key Search Test discriminated significantly between intact and impaired executive function (AUC = 0.677, P < 0.001), sensitivity and specificity were low and no optimal cut-off point could be determined. Conclusion:The Key Search test might not be an appropriate measure of executive functions in cognitively impaired individuals.