The –Roediger–Deese–Roediger–McDermott (DRM) paradigm is a procedure in cognitive psychology used to study false memory in humans. The procedure was pioneered by James Deese in 1959, but it was not until Henry L. Roediger III and Kathleen McDermott extended the line of research in 1995 that the paradigm became popular. The procedure typically involves the oral presentation of a list of related words (e.g., bed, rest, awake, tired, dream, wake, snooze, blanket, doze, slumber, snore, nap, peace, yawn, drowsy) and then requires the subject to remember as many words from the list as possible. Typical results show that subjects recall a related but absent word (e.g., sleep), known as a 'lure', with the same frequency as other presented words. When asked about their experience after the test, about half of all participants report that they are sure that they remember hearing the lure, indicating a false memory – a memory for an event that never occurred.
The simplicity of the paradigm and the ease with which DRM studies can be conducted have helped the DRM paradigm become popular among human memory researchers, as well as researchers from other fields.
Background
The foundations of the DRM paradigm were developed by James Deese while working at Johns Hopkins University. In his 1959 article, "On the prediction of occurrence of particular verbal intrusions in immediate recall", Deese attempted to better understand why, when reciting a previously learned list of words, people sometimes recall a word that was never presented. He orally presented 50 undergraduate students with lists of 12 words, all strongly associated to an absent critical lure, and then immediately after each list was presented asked the students to recall all the items from the list. He found that the critical lure was recalled up to 44% of the time, but that this result varied over different lists. Although all the words in any list were associated with the critical lure, Deese found that the likelihood of false recall depended heavily on the ability of the list words to activate the critical lure – for example Deese claimed that a list containing 'short' could produce recall of the lure 'man', but a list containing 'man' could not produce recall of the lure 'short'.
Other research into false memories had tended to rely on experiences or stories, rather than word lists. Frederic Bartlett famously pioneered this area of research with his studies on remembering using the Indian folktale 'The war of the ghosts'. His studies had British college students learn the Indian folktale and then recall it again and again over time. He found that performance decreased over time, but also found that over time the students 'remembered' the story in a manner that increasingly followed British cultural norms. Although many researchers had trouble replicating Bartlett's results, a number of researchers followed this precedent of using meaningful prose to probe false memories, leaving the more controlled method of list learning underrepresented in the literature. While a few studies had looked at false memories for word lists, their results were not robust and tended to show very small effects.
Roediger and McDermott
Little attention was given to Deese's experiment until the early 1990s when Henry L. Roediger III came across the 1959 article and decided to further explore the findings. Roediger eventually offered the project to his PhD student Kathleen McDermott, who completed the experiments as part of her PhD dissertation.
First, Roediger and McDermott replicated Deese's research by using the six lists from Deese's study that were the most successful in producing false recall. Roediger read the lists of 12 words to a class of students, and after each list asked them to recall as many words as possible from that list. Following the recall of the sixth list the students were given a pen-and-paper recognition memory test: a list of words comprising 12 studied and 30 unstudied items (including the critical lures) on which the students rated how confident they were that each word had appeared on one of the previous lists. The results showed that students recalled the critical lure 40% of the time, and that most were confident that the critical lures had actually appeared on the lists.