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Previous studies have clearly demonstrated that the development of orthographic representations relies on phonological recoding. However, substantial questions persist about the remaining unexplained variance in the acquisition of word-specific orthographic knowledge that is still underspecified. The main aim of this study was to explore whether two cognitive factors-sensitivity to orthographic regularities and short-term memory (STM) for serial order-make independent contributions to the acquisition of novel orthographic representations beyond that of the phonological core component and the level of preexisting word-specific orthographic knowledge. To this end, we had children from second to sixth grades learn novel written word forms using a repeated spelling practice paradigm. The speed at which children learned the word forms and their long-term retention (1week and 1month later) were assessed. Hierarchical regression analyses revealed that phonological recoding, preexisting word-specific orthographic knowledge, and order STM explained a portion of the variance in orthographic learning speed, whereas phonological recoding, preexisting word-specific orthographic knowledge, and orthographic sensitivity each explained a portion of variance in the long-term retention of the newly created orthographic representations. A secondary aim of the study was to determine the developmental trajectory of the abilities to acquire novel orthographic word forms over the course of primary schooling. As expected, results showed an effect of age on both learning speed and long-term retention. The specific roles of orthographic sensitivity and order STM as independent factors involved in different steps of orthographic learning are discussed., (Copyright © 2015 Elsevier Inc. All rights reserved.)

This study assesses the dissociability of phonological and lexical-semantic short-term memory (STM) in two aphasic patients, B.N. and T.M., and explores the relationship between their STM deficits and their word production impairment. Picture naming performance suggests phonological language production impairment in B.N. and lexical-semantic language production impairment in T.M. On STM tasks, B.N. presented phonological STM impairment with preserved lexical-semantic STM, while T.M. presented the reverse profile. These results reveal a double dissociation between phonological and lexical-semantic STM capacities and suggest that our patients' STM impairment may be selectively related to their language production deficits.

Studies of monolingual speakers have shown a strong association between lexical learning and short-term memory (STM) capacity, especially STM for serial order information. At the same time, studies of bilingual speakers suggest that phonological knowledge is the main factor that drives lexical learning. This study tested these two hypotheses simultaneously in participants with variable levels of English-French bilingual proficiency. A word-nonword paired-associate learning task was administered, with nonwords obeying French phonotactic patterns. French phonological knowledge was estimated by a composite French proficiency score summarizing productive and receptive French vocabulary knowledge as well as quantitative and qualitative measures of French exposure. STM measures maximized retention of order information (serial order reconstruction) or retention of phonological item information (single nonword delayed repetition). The French proficiency score and the serial order STM measure independently predicted performance on the paired-associate learning task. These results highlight the conjoined role of phonological knowledge and serial order STM in lexical learning. Importantly, serial order STM remains a strong predictor of lexical learning, even for bilingual individuals who have broad phonological knowledge.

We measured brain activity in 12 adults for the repetition of auditorily presented words and nonwords, before and after repeated exposure to their phonological form. The nonword phoneme combinations were either of high (HF) or low (LF) phonotactic frequency. After familiarization, we observed, for both word and nonword conditions, decreased activation in the left posterior superior temporal gyrus, in the bilateral temporal pole and middle temporal gyri. At the same time, interaction analysis showed that the magnitude of decrease of activity in bilateral posterior temporal lobe was significantly smaller for LF nonwords, relative to words and HF nonwords. Decrease of activity in this area also correlated with the size of behavioral familiarization effects for LF nonwords. The results show that the posterior superior temporal gyrus plays a fundamental role during phonological learning. Its relationship to sublexical and lexical phonological processing as well as to phonological short-term memory is discussed.

Abstract Although phonological processing is generally considered to be a proficiency in Williams syndrome (WS), there are very few studies which have extensively explored phonological processing abilities in WS. In this study, we re-assessed phonological processing in WS by exploring verbal STM and phonological awareness abilities in 4 children with WS (CA: 10-12 years) and two control groups, one matched for chronological age (CA) and the other matched for verbal mental age (VA). Our results confirm and extend previous claims of preserved phonological STM in WS by showing specifically preserved STM performance for non-words, compared to both VA and CA control groups. However, we observed that this was the case only for non-words where support of phonological and lexico-semantic knowledge was minimized, with reduced phonological and lexico-semantic effects on STM performance. Furthermore, a more direct assessment of phonological processing abilities through phonological awareness tasks showed impaired performance for the 4 WS children. Our data confirm that STM for non-words represents a real strength in WS but they do not support previous assumptions of a more general preservation of phonological processing abilities in WS. Implications for impaired and preserved cognitive processes underlying verbal STM and phonological awareness abilities in WS are discussed.

Recent studies have made a distinction between short-term storage capacities for phonological information and short-term storage capacities for lexico-semantic information (R. Martin, Lesch, & Bartha, 1999). In this multiple case study, we tried to provide further evidence for the dissociability of phonological and lexico-semantic short-term memory (STM) components, by studying verbal STM in three patients who had recovered from Landau-Kleffner syndrome. Furthermore, we explored to what extent apparent dissociations between phonological and lexico-semantic STM could be related to underlying phonological and lexico-semantic processing impairments. We found clear dissociations between phonological and lexico-semantic STM measures in patients TG, JPH, and DC, whose performance was impaired in nonword immediate serial recall and in a rhyme probe task, while performance was normal for a category probe task. These patients also presented reduced phonological effects (word length, phonological similarity, phonotactic frequency) but normal lexico-semantic effects (lexicality, word imageability, word frequency) in STM. Moreover, there were no systematic correspondencies between phonological and lexico-semantic STM and phonological and lexico-semantic processing impairments. Implications for current models of STM and language processing are discussed. [ABSTRACT FROM AUTHOR]