Bilingual working memory span is affected by language skill

A complex span procedure was used to study whether there is a measurable extra load on general working memory (WM) when a not fully automatised language has to be comprehended. Participants verified heard sentences in relation to simultaneously shown pictures and memorised the last word of each sentence. The sentences were presented in growing set sizes and recall of all the last words was required after each set. The largest number of sentences that could be processed in combination with successful recall of their last words determined the participant's WM span. Sentences were either in the participants' native language or a well-mastered second language, English. Participants were psychology and English students. WM span and decision accuracy were better for native-language than foreign-language sentences, especially for the psychology students. A second experiment ascertained that the difference between participant groups could not be explained by variables related to phonological shortterm memory or word processing. A third experiment controlled for systematic trade-off differences between languages and groups. We conclude that aspects of sentence comprehension in foreign language develop with practice so that they require less WM resources.     

Forgetting and redintegration of consonants and vowels in pseudoword lists

Immediate recall of phonemes was studied in a pseudoword span task. Finnish participants recalled lists of increasing length, consisting of C(consonant)V(vowel)CVCV pseudowords. The lists were made up from pools of 12 pseudowords. There were three types of lists. In the non‐redundant lists the items were unpredictable combinations of consonants and vowels. In consonant‐redundant lists, all items had the consonant frame /t/_/s/_/l/. In vowel‐redundant lists, all items had the vowel frame _/u/_/e/_/o/. Unlike redundant last syllables in a previous experiment, neither consonant nor vowel redundancy helped list recall. Instead, a harmful phonological similarity effect was apparent in the vowel‐redundant case but not the consonant‐redundant case. A phoneme‐level analysis of recall showed that consonants were recalled better in consonant‐redundant lists and vowels were recalled better in vowel‐redundant lists compared to non‐redundant lists. Vowels appeared to be more important for discrimination between items, with redundancy resulting in confusions. The consequences of phoneme‐level forgetting and redintegration for item‐ and list‐level recall are discussed.