Copyright 1996 Psychologica Belgica. Author version of the paper reproduced here with permission from the publisher.The aim of the present study was to pursue the research on the affective primacy hypothesis, which claims that positive and negative affective reactions can be evoked with minimal stimulus input and virtually no cognitive processing (Zajonc, 1980). In line with Murphy and Zajonc (1993) a priming paradigm was used. The present work is basically a replication of their study in which the effects of affective priming under very brief (suboptimal - 4 ms) and longer (optimal - 1000 ms) exposure durations were compared, but using two additional exposure durations: 30 ms and 100 ms. Like Murphy and Zajonc, facial expressions were used as affective primes in addition to pictures which portrayed scenes and situations of everyday life. These were obtained in a preliminary study. Contrary to Murphy and Zajonc's results, the affective primes only produced significant shifts in subjects' preferential judgements of novel stimuli at longer exposure durations. At suboptimal exposures the novel stimuli were not judged differentially when primed with positive or negative affect. This was true for both facial expressions and pictures. Facial expressions influenced the liking ratings of the ideographs only at exposure durations of 30 ms and longer; pictures not until they were exposed for at least 100 ms. Thus, pictures depicting daily events require longer exposure durations than facial expressions in order to elicit an affective reaction. These results however do not provide any clear-cut evidence in support of the affective primacy hypothesis. Instead, they seem to suggest that affective stimuli do not evoke an affective reaction without additional cognitive processing, a conclusion that is supported by LeDoux’s theory of affective-cognitive interaction in the brain