The effects of ageing and Alzheimer's disease on semantic and gender priming (original) (raw)
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Semantic and gender priming in Frontotemporal Dementia
Frontiers in Neuroengineering, 2009
Modifications of language processing can be observed both in normal ageing and in the most common forms of degenerative dementia, such as Alzheimer's disease and the spectrum of frontotemporal dementias. The present experiment tests at the same time semantic and syntactic aspects of language processing in patients with frontotemporal dementia, using an on-line paradigm that allows researchers to evaluate the real linguistic competence of the patients.
Lexical Priming in Alzheimer's Disease and Aphasia
European Neurology, 2013
Perceptual implicit memory tasks are those in which memory is cued by a stimulus that is physically related to the target stimulus. The aim of the present work is to study perceptual lexical priming in physiological aging, Alzheimer's disease (AD) and in aphasic patients using word-stem completion (WSC) as the lexical priming task, which requires production processing. It is now well known that patients with AD exhibit lexical and semantic deficits [7-11]. Aphasia is also an acquired communication disorder, but does not affect intelligence. Several studies have suggested that aphasia involves lexical-semantic problems [12-17]. The experimental evidence concerning the effect of age on implicit memory is heterogeneous. Some studies have failed to detect age differences in priming [18-25] , while others have confirmed the effect of age on priming [1, 26-28]. Fleischman and Gabrieli [29] found that 85% of normal aging studies reported age invariance in priming. A recent study of our research group [1] found that elderly normal subjects obtained lower lexical priming scores than those of young subjects on a WSC task. AD offers somewhat inconsistent evidence as regards the effects of lexical priming. Some investigators have reported a priming deficit in AD [30-37] , whereas others have found no differences in priming effects between patients with AD and normal control participants [38-48]. Thus, Fleischman and Gabrieli [29] found that 65% of AD studies reported that priming was normal. A recent study
What dementia can do to language processing
2016
The thesis at hand focuses on two main aspects: Firstly, the written text production in the preclinical phase of the semantic variant of primary progressive aphasia embedded in a longitudinal study; secondly, on the examination of Proper Names in patients suffering from Alzheimer´s Disease in a fluency task setting. Both studies focus on aspects which have not been subject to scientific research so far. The broad analysis of linguistics in written text production covered the levels of semantics, syntax and morphology and also included the examination of vocabulary and punctuation. The results showed an early onset of symptoms (approximately nine years before the clinical diagnose took place). Most surprising was the finding of an overwhelming amount of morphologic errors and an extreme usage of quotation marks. The results thus deepen the insight in the process of how the syndrome manifests itself in text production even before clinical diagnosis takes place. The fluency tasks for P...
Effects of Semantic Impairment on Language Use in Alzheimer's Disease
Seminars in Speech and Language, 2008
Many studies present apparently conflicting results and conclusions about the effects of Alzheimer's disease (AD) on language use. This review attempts to reconcile these apparently conflicting results regarding the language impairments in AD by discussing how the slow deterioration of the semantic system at the feature level interacts with the task demands of tests used to evaluate performance. In particular, performance is impaired on tasks that require relatively complete, elaborate semantic representations but is preserved when the task requires only partial semantic representations consisting largely of shared features. The variety of language impairments reported in complex, multiword tasks are likely attributable to a combination of the deterioration of semantic representations and reduced working memory resources. The few available treatment studies for language impairments in AD suggest that treatments designed for adults with other language impairments, such as aphasia, may also be effective in AD.
Neuropsychologia, 2009
Two experiments examined processing of lexical ambiguity in healthy older control (HC), mild cognitive impairment (MCI) and Alzheimer's disease (AD) participants. In Experiment 1, groups of HC, MCI and AD participants took part in an ERP study in which they read lexically ambiguous items presented in a subordinate context and primed by the same item presented in a dominant context. Ambiguous items were homonyms (e.g., bank), metaphorical polysemes (e.g., star), or metonyms (e.g., rabbit). All participants exhibited smaller N400s for items preceded by a related prime. In addition, HC participants exhibited a smaller N400 for metonyms than for metaphorical polysemes or homonyms; this effect was diminished in MCI and AD participants. In Experiment 2, HC and MCI participants completed a primed lexical decision task where targets related to the subordinate meaning/sense of ambiguous items were preceded by primes biasing the dominant meaning/sense (e.g., financial-bank-river). In contrast to the results of Experiment 1, both HC and MCI participants showed priming for metonymic items, but not homonyms or metaphorical polysemes. These results suggest that basic knowledge of multiple senses of metonyms is preserved in MCI, but the processing advantage conveyed by this semantic richness is diminished in MCI and AD.
PLoS ONE, 2022
Introduction Linguistic disorders are one of the common problems in Alzheimer’s disease, which in recent years has been considered as one of the key parameters in the diagnosis of Alzheimer (AD). Given that changes in sentence processing and working memory and the relationship between these two activities may be a diagnostic parameter in the early and preclinical stages of AD, the present study examines the comprehension and production of sentences and working memory in AD patients and healthy aged people. Methods Twenty-five people with mild Alzheimer’s and 25 healthy elderly people participated in the study. In this study, we used the digit span to evaluate working memory. Syntactic priming and sentence completion tasks in canonical and non-canonical conditions were used for evaluating sentence production. We administered sentence picture matching and crossmodal naming tasks to assess sentence comprehension. Results The results of the present study revealed that healthy elderly people and patients with mild Alzheimer’s disease have a significant difference in comprehension of relative clause sentences (P <0.05). There was no significant difference between the two groups in comprehension of simple active, simple active with noun phrase and passive sentences (P> 0.05). They had a significant difference in auditory and visual reaction time (P <0.05). Also there was a significant difference between the two groups in syntactic priming and sentence completion tasks. However, in non-canonical condition of sentence completion, the difference between the two groups was not significant (P> 0.05).
Syntactic Comprehension Deficits in Alzheimer's Disease
Brain and Language, 2000
Syntactic comprehension of German patients with dementia of the Alzheimer type was investigated and compared to healthy controls matched with respect to age, sex, and education. Special attention was directed at syntactic structures, which, in contrast to a language like English, are feasible in a grammatically rich language like German. In a sentence picture matching paradigm, only semantically reversible sentences were used. Syntactic complexity ranged from simple active voice sentences to more complex sentences like center-embedded object relative sentences. In comparison to their controls, patients showed a deficit in nearly all categories. Their performance was not influenced by age, but was heavily influenced by the degree of cognitive impairment. Patients with mild cognitive impairment, as defined by a MMSE score of 20 or higher, showed only slight difficulties in syntactic processing, whereas patients with moderate to severe impairment (MMSE Ͻ 20) did not perform above chance limits in most syntactic categories. It appears as though syntactic comprehension is only mildly affected in the early stages of Alzheimer's disease and is rather severely impaired in more advanced stages. In the present report, results are discussed in terms of working memory demands for syntactic processing.
Brain and Language, 2001
The nature of the semantic memory deficit in dementia of the Alzheimer's type (DAT) was investigated in a semantic priming task which was designed to assess both automatic and attention-induced priming effects. Ten DAT patients and 10 age-matched control subjects completed a word naming semantic priming task in which both relatedness proportion (RP) and stimulus-onset asynchrony (SOA) were varied. A clear dissociation between automatic and attentional priming effects in both groups was demonstrated; however, the DAT subjects' pattern of priming deviated significantly from that of the normal controls. The DAT patients failed to produce any priming under conditions which encouraged automatic semantic processing and produced facilitation only when the RP was high. In addition, the DAT group produced hyperpriming, with significantly larger facilitation effects than the control group. These results suggest an impairment of automatic spreading activation in DAT and have implications for theories of semantic memory impairment in DAT as well as models of normal priming.
Sensitivity to gender, person, and tense inflection by persons with Alzheimer’s disease
Brain and Language, 2003
This paper investigates sensitivity to gender, person, and tense inflection in individuals with AlzheimerÕs disease (AD) in on-line and off-line tasks. Fourteen persons with AD and 14 matched controls participated in two studies: sensitivity to gender incongruity was tested in an on-line reading task and sensitivity to violation of tense and person was tested with an off-line grammaticality judgement test. Group performance was comparable on both tasks. It is argued that patientsÕ preserved sensitivity to these features is primarily a function of the simplicity of the required operations. The notion of simplicity in this context is discussed and various parameters are offered for future investigation.
Journal of the International Neuropsychological Society, 1999
Two experiments are reported that explore the influence of strength of the prime-target relationship on the observed priming effects in young, healthy old, and individuals diagnosed with dementia of the Alzheimer type (DAT). In Experiment 1, participants were auditorily presented primes (FURNITURE) and after varying delays presented visual targets that were (1) high-strength related (e.g., SOFA), (2) low-strength related (e.g., RUG), or (3) unrelated control words (e.g., COW or DEER). The results indicated that the DAT individuals produced relatively larger priming effects than both the young and the healthy old, but these data could be accommodated by increases in effect size due to general slowing of response latencies. In Experiment 2, the same cross-modal priming paradigm was used with ambiguous words presented as primes (e.g., BANK) and either high-dominant (e.g., MONEY) or low-dominant (e.g., RIVER) words as targets. The results of Experiment 2 produced a qualitatively distinct pattern of priming that indicated DAT individuals only produced priming for high-dominant targets and not for low-dominant targets, whereas, the healthy control groups produced equivalent priming for both high-and low-dominant targets. The discussion focuses on the implication that these results have for the interpretation of semantic priming effects, in general, along with implications for the apparent semantic memory loss in DAT individuals. (JINS, 1999, 5, 626-640.)