Blog Archives

Short-term memory stages in sign vs. speech: The source of the serial span discrepancy

Speakers generally outperform signers when asked to recall a list of unrelated verbal items. This phenomenon is well established, but its source has remained unclear. In this study, we evaluate the relative contribution of the three main processing stages of short-term memory – perception, encoding, and recall – in this effect. The present study factorially manipulates whether American Sign Language (ASL) or English is used for perception, memory encoding, and recall in hearing ASL-English bilinguals. Results indicate that using ASL during both perception and encoding contributes to the serial span discrepancy. Interestingly, performing recall in ASL slightly increased span, ruling out the view that signing is in general a poor choice for short-term memory. These results suggest that despite the general equivalence of sign and speech in other memory domains, speech-based representations are better suited for the specific task of perception and memory encoding of a series of unrelated verbal items in serial order through the phonological loop. This work suggests that interpretation of performance on serial recall tasks in English may not translate straightforwardly to serial tasks in sign language.

from Cognition

A case for the involvement of phonological loop in sentence comprehension

We suggest that the neural correlates of the phonological loop, left BA40 and BA44, are both involved in the comprehension of syntactically complex sentences, while only left BA40, corresponding to the short-term store, is recruited for the comprehension of long but syntactically simple sentences. Therefore, in contrast with the dominant view, we showed that sentence comprehension is a function of the phonological loop.

from Neuropsychologia

Phonological working memory impairments in children with specific language impairment: where does the problem lie?

We were able to ascertain which aspects of lexical learning are most problematic for children with SLI in terms of fast-mapping. These findings may allow clinicians to focus intervention on known areas of weakness. Future directions include extending these findings to slow mapping scenarios.

from the Journal of Communication Disorders

The contribution of working memory capacity to foreign language comprehension in children

The present study examined the contribution of working memory processes in children’s foreign language processing of sentences and short stories. A total of 95 children were given measures of working memory when 9-10 years old. One to two years later at ages 11-12, tasks tapping foreign language literal comprehension (English) and native language inferential comprehension (Swedish) were administered. Regression and correlation analyses demonstrated that both central executive and phonological loop processes predicted foreign language comprehension, whereas central executive processes but not phonological loop processes predicted native language reading comprehension. These findings show that children’s foreign language processing is supported by their working memory capacity tested in their native language. Some of these working memory resources appear to be unique for foreign language. The strong association between native language and foreign language processing suggests that an important factor in becoming proficient in foreign language is the child’s general language aptitude. Possible mechanisms for the contribution of working memory to children’s foreign language comprehension are discussed.

from Memory

Slave to the rhythm: Experimental tests of a model for verbal short-term memory and long-term sequence learning

Three experiments tested predictions of a neural network model of phonological short-term memory that assumes separate representations for order and item information, order being coded via a context-timing signal [Burgess, N., & Hitch, G. J. (1999). Memory for serial order: A network model of the phonological loop and its timing. Psychological Review, 106, 551–581005D]. Predictions were generated for long-term sequence learning and tested using the Hebb Effect, the improvement in immediate serial recall when a list is repeated. Results confirmed predictions that the Hebb Effect would be (1) insensitive to phonemic similarity and articulatory suppression, variables that impair immediate recall without affecting the context-timing signal and (2) reduced if the context-timing signal is altered by varying the temporal grouping pattern of the repeated list. Results highlighted an interesting shortcoming of the model in that participants were able to learn more than one sequence simultaneously. However, this problem was addressed by extending the model to include multiple context representations and a sequence-recognition process.

from the Journal of Memory and Language