(Not) acquiring meaning in a second language: Are input deficits key?

Word meanings are not always parallel across languages, and second language (L2) learners often use words in non-native ways. Is the learning problem inherent in maintaining conflicting word-to-meaning mappings within an integrated lexical network, or is it due to insufficient attention to and input for acquiring L2 mappings? To help discriminate between these possibilities, we gave English speakers repeated exposures to 40 brief videos of actions, labeled with five novel words that cross-cut English labeling patterns. Half the participants were told only to learn the labels for the actions. The other half were told to figure out their meanings, which might differ from English. The Figure Out Meanings group made test choices faster and were also slightly more likely to produce definitions capturing the intended meanings. However, both groups performed well above chance in generalizing the novel words. High levels of choice performance for both groups point to insufficient input, rather than inherent properties of lexical networks, as the critical limiting factor in more typical L2 learning contexts. Speed and definition performance hint at some advantage to explicit attention in sorting out L1-L2 differences.