Semantic memory is key to binding phonology: Converging evidence from immediate serial recall in semantic dementia and healthy participants

NEUROPSYCHOLOGIA

卷:47

Article

Hoffman, Paul¹  Jefferies, Elizabeth²  Ehsan, Sheeba¹  Jones, Roy W.³  Ralph, Matthew A. Lambon¹ 

[1] Univ Manchester, Sch Psychol Sci, Neurosci & Aphasia Res Unit, Manchester M13 9PL, Lancs, England

[2] Univ York, York YO10 5DD, N Yorkshire, England

[3] Royal United Hosp, RICE Res Inst Care Older People, Bath BA1 3NG, Avon, England

关键词: Semantic binding;    Interactive activation;    Immediate serial recall;    Serial position effects;   

DOI  :  10.1016/j.neuropsychologia.2008.12.001

来源: Elsevier

【 摘 要 】

Patients with semantic dementia (SD) make numerous phoneme migration errors when recalling lists of words they no longer fully understand, suggesting that word meaning makes a critical contribution to phoneme binding in verbal short-term memory. Healthy individuals make errors that appear similar when recalling lists of nonwords, which also lack semantic support. Although previous studies have assumed that the errors in these two groups stem from the same underlying cause, they have never been directly compared. We tackled this issue by examining immediate serial recall for SD patients and controls on pure word lists and mixed lists that contained a mixture of words and nonwords. SD patients were equally poor at pure and mixed lists and made numerous phoneme migration errors in both conditions. In contrast, controls recalled pure lists better than mixed lists and only produced phoneme migrations for mixed lists. We also examined the claim that semantic activation is critical for words in the primacy portion of the list. In fact, the effect of mixed lists was greatest for later serial positions in the control group and in the SD group recall was poorest towards the ends of lists. These results suggest that mixing nonwords with words in healthy participants closely mimics the impact of semantic degradation in SD on word list recall. The study provides converging evidence for the idea that lexical/semantic knowledge is an important source of constraint on phonological coherence, ensuring that phonemes in familiar words are bound to each other and emerge together in recall. (C) 2008 Elsevier Ltd. All rights reserved.

【 授权许可】

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