This research examined the role of thought suppression in the formation of mental blocks. In Experiment 1, participants were asked to generate a series of creative associates for two target words after initially suppressing a word that was semantically related to one of the two target words. Participants produced fewer responses, and experienced a greater sensation of being mentally blocked, when attempting to produce associates for the target word that was semantically related to the suppressed word. In Experiment 2, participants (...) either thought about or suppressed a series of words prior to completing a word fragment completion task. Each word either corresponded exactly to one of the word fragment solutions or resembled one of the solutions but was slightly different in its orthographic properties . Participants performed most poorly on the items for which they had initially suppressed negative primes. (shrink)