TY - JOUR
T1 - A semantic contribution to nonword recall? Evidence for intact phonological processes in semantic dementia
AU - Jefferies, Elizabeth
AU - Jones, Roy W.
AU - Bateman, David
AU - Lambon Ralph, Matthew A.
PY - 2005/3
Y1 - 2005/3
N2 - Patients with semantic dementia make numerous phonological errors in their immediate serial recall of words that they understand poorly. Previous studies have argued that these errors result from a reduction in the normal contribution made by semantics to the coherence of items in the phonological system. It is possible, however, that the errors might reflect additional subtle phonological deficits. Six patients with semantic dementia were tested on a variety of phonological processing and short-term memory tasks, in order to explore these possibilities. For the most part, the patients showed normal performance in phonological awareness and discrimination tasks and normal effects of phonological similarity and word length in immediate serial recall. The more severely impaired patients, however, showed some weakness on tests of nonword repetition and recall. Every patient showed better recall of words that were still relatively well understood, compared with words that were more semantically degraded. This difference extended to nonwords that were phonologically similar to the known and degraded words, suggesting that the patients' semantic deficits could account for their impairments in nonword recall. The recall advantage for semantically known over degraded items also extended to a nonverbal delayed picture copying task, suggesting that the patients' immediate serial recall impairments were underpinned by a central semantic deficit, and not by a separable lexical deficit. © 2005 Psychology Press Ltd.
AB - Patients with semantic dementia make numerous phonological errors in their immediate serial recall of words that they understand poorly. Previous studies have argued that these errors result from a reduction in the normal contribution made by semantics to the coherence of items in the phonological system. It is possible, however, that the errors might reflect additional subtle phonological deficits. Six patients with semantic dementia were tested on a variety of phonological processing and short-term memory tasks, in order to explore these possibilities. For the most part, the patients showed normal performance in phonological awareness and discrimination tasks and normal effects of phonological similarity and word length in immediate serial recall. The more severely impaired patients, however, showed some weakness on tests of nonword repetition and recall. Every patient showed better recall of words that were still relatively well understood, compared with words that were more semantically degraded. This difference extended to nonwords that were phonologically similar to the known and degraded words, suggesting that the patients' semantic deficits could account for their impairments in nonword recall. The recall advantage for semantically known over degraded items also extended to a nonverbal delayed picture copying task, suggesting that the patients' immediate serial recall impairments were underpinned by a central semantic deficit, and not by a separable lexical deficit. © 2005 Psychology Press Ltd.
U2 - 10.1080/02643290442000068
DO - 10.1080/02643290442000068
M3 - Article
SN - 1464-0627
VL - 22
SP - 183
EP - 212
JO - Cognitive Neuropsychology
JF - Cognitive Neuropsychology
IS - 2
ER -