The memory block effect (MBE) occurs when orthographically similar words inhibitretrieval. Previous studies have published 55 different stimuli that produce the MBE in word fragment completion. This small number of stimuli constrains experimental designs, presents serious obstacles for using neuroimaging to elucidate neural substrates of blocking, and raises concern that the MBE is limited to a particular group of words. A pool of 315 stimulus words was tested in a traditional MBE paradigm, and the results demonstrated that the MBE generalizes to other stimuli. This study also expands the number of stimuli that produce the MBE because 185 new stimuli produced blocking effects. As a result, the current list of 240 MBE stimuli can be used for word fragment research including cognitive neuroscience investigations of retrieval inhibition. A table of MBE stimuli is available in an archived appendix that can be downloaded from www.psychonomic.org/archive.
Participants are exposed to words that complete test fragments (positive primes) and other words that are orthographically similar to the solutions but cannot complete the fragment (blocking primes). Memory is then tested using an incidental memory test that involves completing word fragments.