Cognitive Mechanisms for Processing Nonwords: Evidence from Alzheimer's Disease

Glosser, Guila; Friedman, Rhonda B.; Kohn, Susan E.; Sands, Laura P.; Grugan, Patrick

doi:10.1006/brln.1997.1924

Cited by 21 publications

(14 citation statements)

References 41 publications

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“…Error scoring using these criteria has previously been verified by the investigators in samples of control and AD subjects. Interrater agreement for error classification was found to be Ͼ90% in AD and normal control groups (Glosser et al, , 1998.…”

Section: Methodsmentioning

confidence: 93%

“…If the subject is unable to use orthography to access a semantic representation, then we presume that the subject will not be able to use semantic information to bind the sublexical elements of the word into a coherent phonological representation, making the task a suitable one for testing hypotheses regarding the role of semantics in oral reading. Word-picture-matching tasks are generally considered good indicators of single-word reading comprehension and have been widely used to measure semantic ability in a variety of patient populations (Parkin, 1993;Price et al, 1998;Glosser et al, 1998;. However, although the task provides an accurate measure of overall semantic ability, it should be noted that the words used in this task are not the same as those used in the oral reading or repetition tasks; we therefore have no direct measure of the patients' ability to comprehend the words used in these tasks.…”

Section: Discussionmentioning

confidence: 99%

“…The first reading task was designed to test the ''regularity effect'' (Glosser, Grugan, & Friedman, 1998). The list included 72 one-and two-syllable stimuli that are real words, with equal numbers of high-frequency and low-frequency regular, ambiguous, and exceptional words.…”

Section: Methodsmentioning

confidence: 99%

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Oral Reading in Dementia

2000

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Section: Methodsmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

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Oral Reading in Dementia

2000

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“…Although phonological processing was initially thought to be preserved in AD, mainly on the basis of spontaneous speech reports [Nicholas et al, 1985], more detailed assessments have reported impaired phonological abilities in even mild AD patients. For instance, consistent difficulties have been described in phoneme discrimination, letter fluency, or single nonword repetition tasks [Croot et al, 2000;Glosser et al, 1997Glosser et al, , 1998]. …”

Section: Introductionmentioning

confidence: 92%

Neural substrates of phonological and lexicosemantic representations in Alzheimer's disease

Peters

Majerus

Collette

et al. 2007

Human Brain Mapping

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Abstract:The language profile of patients suffering from Alzheimer's disease (AD) is characterized not only by lexicosemantic impairments but also by phonological deficits, as shown by an increasing number of neuropsychological studies. This study explored the functional neural correlates underlying phonological and lexicosemantic processing in AD. Using H 215 O PET functional brain imaging, a group of mild to moderate AD patients and a group of age-matched controls were asked to repeat four types of verbal stimuli: words, wordlike nonwords (WL1), non-wordlike nonwords (WL2) and simple vowels. The comparison between the different conditions allowed us to determine brain activation preferentially associated with lexicosemantic or phonological levels of language representations. When repeating words, AD patients showed decreased activity in the left temporo-parietal and inferior frontal regions relative to controls, consistent with distorted lexicosemantic representations. Brain activity was abnormally increased in the right superior temporal area during word repetition, a region more commonly associated with perceptual-phonological processing. During repetition of WL1 and WL2 nonwords, AD patients showed decreased activity in the middle part of the superior temporal gyrus, presumably associated with sublexical phonological information; at the same time, AD patients showed larger activation than controls in the inferior temporal gyrus, typically associated with lexicosemantic levels of representation. Overall, the results suggest that AD patients use altered pathways to process phonological and lexicosemantic information, possibly related to a progressive loss of specialization of phonological and lexicosemantic neural networks. Hum Brain Mapp 30: [185][186][187][188][189][190][191][192][193][194][195][196][197][198][199] 2009. V V C 2007 Wiley-Liss, Inc.

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“…To date, however, phonological deficits across groups of patients have mainly been reported in the context of experimental sentence repetition or nonword tasks which are not typical of speech production in everyday life and/or rely heavily on immediate memory (Biassou et al, 1995;Glosser et al, 1998;Glosser et al, 1997), while data on single cases have primarily been anecdotal and brief. Furthermore, although some reports provide neuropsychological results and phonological error rates Kennedy et al, 1995) it is not clear whether there is a consistent clinical profile in DAT patients with impaired speech sound production, nor whether the speech production deficits are themselves consistent when they arise in DAT.…”

Section: Demic Pressmentioning

confidence: 99%