British English norms for the spontaneous completion of three-letter word stems

Abstract

Word stem completion tasks involve showing participants a number of words and then later asking them to complete word stems to make a full word. If the stem is completed with one of the studied words, it indicates memory. It is a test widely used to assess both implicit and explicit forms of memory. An important aspect of stimulus selection is that target words should not frequently be generated spontaneously from the word stem, to ensure that production of the word really represents memory. In this article, we present a database of spontaneous stem completion rates for 395 stems from a group of 80 British undergraduate psychology students. It includes information on other characteristics of the words (word frequency, concreteness, imageability, age of acquisition, common part of speech, and number of letters) and, as such, can be used to select suitable words to include in a stem completion task. Supplemental materials for this article may be downloaded from http://brm .psychonomic-journals.org/content/supplemental.Word stem completion (WSC) tasks have a long history of use in psychology, where their initial introduction indicated that implicit memory can be preserved in amnesic patients (Warrington & Weiskrantz, 1970). Participants are shown lists of words, unaware of a later memory task. Subsequently, they are presented with the first few letters of a word and are asked to complete this stem with the first word that comes to mind (see Roediger, Weldon, Stadler, & Riegler, 1992, for a review). Explicit memory versions ask for completions that are remembered from the study list (Greene, 1986). An increase in stem completion levels due to preexposure of the words indicates memory. This methodology is still widely used in tasks ranging from cerebral blood flow measures (Sorond, Schnyer, Serrador, Milberg, & Lipsitz, 2008) to behavioral tasks in healthy participants (Benjamin Clarke & Butler, 2008) and patients (e.g., Alzheimer's disease, LaVoie & Faulkner, 2008; schizophrenia, Pope & Kern, 2006).The selection of words to use in WSC tasks is critical. The stem must be able to form multiple words when completed. Words should not be proper nouns and should have sufficient frequency for participants to know them and their meanings. They should have relatively matched imageability and concreteness. Information on these characteristics is available through established databases (e.g., M. Wilson, 1988).One key criterion, particularly important for implicit tasks, is that the words used should not commonly be produced in a spontaneous WSC task. Since participants must generate the first completion that comes to mind, a frequent spontaneous completion reduces the distance between chance and ceiling performance. In imaging studies, "correct" responses would be more likely to be guesses, adding unwanted noise to the neural signal. Matching low levels of spontaneous WSC across word lists-and ideally, all words-ensures that tasks are sensitive and reliable.Spontaneous WSC rates are not easily available, and studies have run p...

Amount, not strength of recollection, drives hippocampal activity: A problem for apparent word familiarity‐related hippocampal activation

“…Importantly, spontaneous generation of each word from its corresponding stem was low with a mean frequency of 0.63% (SD = 0.85) as determined by previous pilot work with a different sample of 80 participants (Migo et al, 2010). Finally, an additional sample of 90 words of the same three-word stems with the target words was used as foils in the forced-choice recognition task.…”

Structural Priming Is Supported By Different Components Of Non-Declarative Memory: Evidence From Priming Across The Lifespan

“…10 of the word-stems could be completed using the verbs used in the structural priming task (randomly selected from the list of verbs each specific participant used) and 10 using novel words (randomly picked from a list of 33 stems). The 33 word-stems to be completed by novel words were selected from a word-stem database by Migo, Roper, Montaldi, and Mayes (2010). The novel word-stems could not be completed with any of the words the participants had been exposed to until this point in the session.…”

Spanish norms for completion of restricted length word stems

“…There are only available norms of unconstrained stem completion of English words (Graf & Williams, 1987;Migo, et al, 2010) and Swedish (Olofsson & Nyberg, 1992), and of constrained stems of French words (Martin et al, 2009) and German words (Bergmann et al, 2010). However, at the present time, there are no norms for completion of constrained and unconstrained Spanish word stems.…”

“…In the case of word frequency and familiarity, some studies have found a positive correlation between these variables and the probability of constrained stem completion (e.g., Martin et al, 2009); that is, stems obtained from high-frequency words are completed more easily than those obtained from low-frequency words. At the same time, the relation between frequency and completion probability has been reported in some studies using unconstrained stems (Graf & Williams, 1987;Mueller & Thanasuan, 2014), although others have failed to find such a relation (Migo, Roper, Montaldi, & Mayes, 2010). Word length is another variable that seems to have some influence on the probability of completion of unconstrained stems (Graf & Williams, 1987), and this effect has been replicated with constrained stems, even though "the true role of length in stem completion remains somewhat difficult to determine" (Mueller & Thanasuan, 2014).…”

“…A review of the literature concerning word stem completion norms reveals that there are norms of unconstrained stems of English (Graf & Williams, 1987;Migo, et al, 2010) and Swedish (Olofsson & Nyberg, 1992) words, and of constrained or restricted stems of five-letter French words (Martin et al, 2009) and five-to seven-letter German words (Bergmann, Müller, & Danek, 2010). In Spanish, the only available database is that developed by Soler, Dasí, and Ruiz (2009), which has 269 unique solution word fragments.…”