Variable Semantic Input and Novel First-Language Vocabulary Learning

Vocabulary learning involves mapping a word form to a semantic meaning. An individual asked to learn the Spanish word for “apple,” for example, must map a new word form (manzana) onto the appropriate semantic representation. Previous studies have found that acoustic variability of word forms can improve second language vocabulary acquisition (Barcroft & Sommers, 2005; Sommers & Barcroft, 2007). The current experiments investigated whether variable semantic input could have a similar beneficial effect on first language vocabulary learning. Participants learned low-frequency English vocabulary words and their definitions. Half of the words were shown with the same verbatim definition at each of the six exposures, while the other half appeared with a differently worded, but synonymous, definition at each of the six exposures. After the learning phase, two cued recall tests were administered. In the first test, each word form was supplied and participants were instructed to write its definition. In the second test, participants were given a novel definition of each word and were asked to provide the correct word form for the definition. Younger adults in Experiment 1 were more accurate for words studied in the variable condition, whereas the accuracy scores of older adults in Experiment 2 did not significantly differ by condition. These results are discussed within the TOPRA model framework (Barcroft, 2002) and the associative deficit hypothesis