Verb confrontation naming and word-picture matching in Alzheimer's disease.

Patients with Alzheimer's disease (AD) were asked to name pictures and perform a multiple-choice word–picture matching task with verbs and nouns. AD patients were significantly more impaired with verbs than nouns for both naming and word–picture matching, and their patterns of semantic naming errors differed for verbs and nouns. One subgroup of AD patients was compromised on both naming and word–picture matching consistent with a semantic memory deficit. Naming was worse for verbs than for nouns in these patients, and they produced significantlv fewer hierarchically related semantic substitutions for verbs than for nouns. Other AD patients without semantic memory difficulty did not demonstrate these form class-sensitive patterns. The investigators hypothesize that form class-specific effects in AD patients' naming are due in part to differences in processing verbs and nouns in semantic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A computational model of naming in Alzheimer's disease: Unitary or multiple impairments?

The predominant explanation for difficulty naming objects in Alzheimer's disease (AD) is impaired semantic memory. Two classes of findings challenge this. The lower the visual quality of the stimulus the less likely AD patients are to name it, suggesting a deficit of visual perception. The lower the name frequency, the less likely AD patients are to name an object, suggesting a deficit of lexical access. A mechanistic explanation is given for why a semantic memory deficit is sufficient to account for this range of data, provided components underlying task performance are interactive. Interactive parallel distributed processing networks were trained to associate visual patterns with semantic and lexical patterns. When semantic units were lesioned, networks were more sensitive to impoverished visual inputs. Networks also made a disproportionate number of errors to items trained with lower frequency and benefited from phonemic cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic space in Alzheimer's disease patients.

A within-category sorting task was used to investigate conceptual relations from 2 semantic categories (animals and occupations) in mild and moderately impaired Alzheimer's disease (AD) patients. A multidimensional scaling analysis was applied to the data. The resulting 2-dimensional solutions indicated that mildly affected AD patients sorted within-category terms in a manner largely consistent with controls' performance but were less consistent in their application of domain knowledge. Moderate AD patients' solutions were less similar to controls' solutions. Mild AD patients' explanations of their sorting schemes were similar to those given by controls but less focused. Together these findings suggest that attribute knowledge may remain largely accessible in mild AD; however a deficiency in recruiting reflective processes in the service of task-related goals may limit the selective application of this information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The naming deficit in early Alzheimer's and vascular dementia.

Patients with early Alzheimer's disease (AD) were compared to normal controls and patients with early vascular dementia (VaD) on their naming errors using the Boston Naming Test (H. Goodglass & E. Kaplan, 1983). All naming errors were classified into 3 general error categories: visuoperceptual, semantic, and phonemic. Semantic errors were further classified into coordinate errors (responses that belong to the same semantic category as the target words), superordinate errors (responses that belong to a broader semantic category than the target word), and functional-circumlocutory errors (circumlocutions and responses that functionally describe the target word). The findings indicated that AD participants display more overall naming errors than VaD participants, although the pattern of general errors was similar between the patient groups. However, the qualitative difference between the patient groups was observed within the semantic errors because the AD group made more superordinate errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Classical conditioning in patients with Alzheimer's disease: A multiday study.

Previous studies demonstrated that patients with Alzheimer's disease (AD) do not acquire the classically conditioned eyeblink response. These studies, however, were only tested over a single conditioning session and, hence, raise the question of whether AD patients are capable of acquiring the response if sufficient training is given. This question may be of some importance because whether AD patients can ultimately acquire the response has implications for the underlying neurobiological deficit in disrupted conditioning in AD. This study tested AD patients and age-matched controls over 4 days. As in previous studies, AD patients performed significantly worse than controls on Day 1, but by Day 4, they were not significantly different from controls. Subsequent testing indicated that these effects were not due to nonassociative variables such as changes in sensitivity to stimuli or disruption of the motor response. Also, it was reported that neither AD patients nor controls showed any evidence of acquisition in an explicitly unpaired paradigm, suggesting that neither pseudoconditioning nor sensitization is contributory. Data are discussed in terms of the possible role of the hippocampus in mediating conditioning deficits in AD patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Focal cognitively mediated blood-flow activation in Alzheimer's disease patients.

Measured regional cerebral blood flow (rCBF), estimated by the 133-Xe inhalation technique, in 7 Alzheimer's disease (AD) patients (mean age 65.6 yrs) and 7 normal elderly Ss (mean age 65.3 yrs) during the performance of a right–left discrimination task, a sensorimotor control task, and at normal rest. Significant focal task-related blood-flow activation, attributable primarily to the complex cognitive components of the cognitive task, was found in the normal and AD Ss. The determination of cognitively mediated activation was accomplished by using the blood-flow activation during sensorimotor task performance to account for most of the attentional and response requirements of the cognitive task. Although overall rCBFs were significantly higher for AD Ss, this did not result in a significant differential, cognitively mediated activation pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Caregiver ratings of personality change in Alzheimer's disease patients: A replication.

Caregivers of 26 patients with Alzheimer's disease (AD) rated current and premorbid personality patterns with the NEO Personality Inventory. Results replicated previous findings on the degree of change reported in a previous group of patients with mixed memory disorder diagnoses. After a diagnosis of AD, the patients were rated as significantly more neurotic, less extraverted, less open, and less conscientious. There were no rated differences of changes in the personality domain of Agreeableness. These results strengthen the usefulness of caregiver ratings of personality change of patients with memory problems who cannot be useful informants on their own behalf. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mere exposure effect in patients with Alzheimer's disease.

The mere exposure effect was examined in patients with mild to moderate Alzheimer's disease (AD). Twenty patients and 20 elderly controls judged the physical characteristics of faces. Implicit memory was tested later by presenting pairs of faces (old and new) and asking participants which faces they liked better. Patients and controls exhibited above chance preference for previously exposed faces. Experiment 2 evaluated whether the preserved implicit memory of patients was mediated by explicit memory. Patients and controls again judged faces but then later chose which faces they had seen before. Patients exhibited impaired recognition memory compared to controls. These findings suggest that a mere exposure affect for unfamiliar faces is present in mild to moderate AD. The results are discussed in terms of perceptual and conceptual priming and relatively spared occipital lobe functioning in early AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intact text-specific implicit memory in patients with Alzheimer's disease.

The ability of patients with Alzheimer's disease (AD) to acquire and retain text-specific knowledge was investigated in a rereading study. Ten AD patients (aged 59–84 yrs) and 10 normal control Ss read 2 passages 3 times, each as quickly as possible, and answered recognition memory questions after the 3rd reading of each passage. The AD patients had poor explicit memory as evidenced by impaired recognition memory for the passages. In contrast, normal decreases in the times required for successive readings of each passage for AD patients indicated intact implicit memory for the passages. The absence of facilitation across passages indicated that the rereading effect was text specific, suggesting that AD patients may retain the ability to form certain kinds of implicit new associations. Alternative accounts of the mechanism underlying text-specific priming, and of the nature of intact and impaired implicit memory in AD, are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurological disorders in dentistry: managing patients with Alzheimer's disease

Alzheimer's disease (AD) is the most prevalent type of dementing illness affecting over four million Americans. It typically occurs after age 60, and prevalence increases with advanced age. As the adult population increases, a greater number of patients with a diagnosis of AD will require dental care. This article reviews the oral and systemic clinical findings seen in AD patients and current medical treatment. Some general and specific suggestions for dental management are presented, including guidelines for restraint and sedation use. Finally, some helpful, adaptive oral devices are recommended for use by caregivers of patients unable to provide for their own daily oral hygiene. Dental providers can and should be willing to make oral care available to patients with a diagnosis of AD. Despite the difficulties involved, the need will continue to be great, and the gratification in caring for these patients makes it worth the effort.     

Verbal and nonverbal fluency in patients with probable Alzheimer's disease.

Verbal fluency (semantic category naming and letter fluency) and nonverbal fluency (semantic category drawing and design fluency) were measured in mildly and moderately demented patients with probable dementia of the Alzheimer type (pDAT), and related to age at onset, disease duration, and disease severity. Group and individual patient analyses revealed impairments within verbal and nonverbal modalities that were most severe on semantic category fluency tasks. Detailed assessments of errors emphasized the role of compromised semantic memory in pDAT patients' impaired fluency, regardless of the modality of response. Fluency performance was related to dementia severity but not to age of onset or disease duration. It is concluded that deficits on measures of fluency in pDAT are due in large part to semantic memory impairments and that fluency may be useful for following disease progression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inference of beliefs and emotions in patients with Alzheimer's disease.

The present study compared 20 patients with mild to moderate Alzheimer's disease with 20 older controls (ages 69-94 years) on their ability to make inferences about emotions and beliefs in others. Six tasks tested their ability to make 1st-order and 2nd-order inferences as well as to offer explanations and moral evaluations of human action by appeal to emotions and beliefs. Results showed that the ability to infer emotions and beliefs in 1st-order tasks remains largely intact in patients with mild to moderate Alzheimer's. Patients were able to use mental states in the prediction, explanation, and moral evaluation of behavior. Impairment on 2nd-order tasks involving inference of mental states was equivalent to impairment on control tasks, suggesting that patients' difficulty is secondary to their cognitive impairments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alzheimer's disease: Current congressional response.

Addresses the public policy component of Alzheimer's disease (AD) by examining legislation (either proposed or passed by Congress) in the areas of research, aid and assistance to AD patients and their families, long-term care, and information dissemination. Barriers to the passage of Alzheimer's legislation in Congress are noted. (49 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of semantic context by patients with Alzheimer's disease.

Used semantic-priming procedures to examine limitations in the use of semantic context by 18 patients (mean age 68.9 yrs) with Alzheimer's disease (AD) and to determine whether any such contextual effects were mediated solely through automatic processes or whether attentional processes were also involved. Three tasks were applied to examine the effect of semantic context on the performance of 18 normal elderly Ss (mean age 67.2 yrs), 18 normal young Ss (mean age 24.1 yrs), and the AD Ss. When normal and AD Ss were asked to decide whether a given item was a member of a certain category, their response times were equally affected by the item's dominance in the category. The time that AD Ss took to recognize a word was actually affected more by the semantic context provided by a priming sentence than was that of normal Ss. When asked to generate the final word of an incomplete sentence, AD Ss performed very poorly unless potential responses were highly constrained by sentence context. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit memory in Alzheimer's disease: A meta-analysis.

Meta-analysis was performed on 33 articles (36 experiments involving 564 Alzheimer's disease [AD] patients and 592 controls). Overall, AD patients were significantly impaired on implicit memory tests, r?=?.163 (a difference of .329 SDs from normal performance). They were impaired on nonverbal tests (e.g., fragmented pictures), word stem completion, classical conceptual tests (e.g, free association), and on word-based perceptual tests with long delays. However, they performed normally on word-based perceptual tests (e.g., perceptual identification of words) with short study test delays. They also performed normally on word stem completion if they were older than 75, possibly because their age-matched controls were also impaired. These results are neither qualified by study list length nor patient mental status. None of the theories in the field is compatible with the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation among stenosis severity, myocardial blood flow, and flow reserve in patients with coronary artery disease

BACKGROUND: Coronary arteriography is considered the "gold standard" for evaluating the severity of a coronary stenosis. Because the resistance to blood flow through a stenotic lesion depends on a number of lesion characteristics, the physiological significance of coronary lesions of intermediate severity is often difficult to determine from angiography alone. This study of patients with coronary artery disease seeks to determine the relation between myocardial blood flow and flow reserve measured by positron emission tomography (PET) and the percent area stenosis on quantitative coronary arteriography. METHODS AND RESULTS: We studied 28 subjects: 18 patients with coronary artery disease (66 +/- 8 years) and 10 age-matched healthy volunteers (64 +/- 13 years) with dynamic N-13 ammonia PET imaging at rest and after dipyridamole (0.56 mg/kg). The percent cross-sectional area stenosis was quantified on the coronary arteriograms as described by Brown et al. In the 18 patients, a total of 41 non-infarct-related coronary vessels were analyzed. Myocardial blood flows in normal regions of patients with coronary artery disease were not different than those in healthy volunteers, both at rest and after dipyridamole. As a result, the myocardial flow reserve was also similar in both groups (2.4 +/- 0.4 versus 2.6 +/- 0.7, respectively; P = NS). Quantitative PET estimates of hyperemic blood flow (r = .81, P < .00001), flow reserve (r = .78, P < .00001), and an index of the "minimal coronary resistance" (r = .78, P < .00001) were inversely and nonlinearly correlated with the percent area stenosis on angiography. Of note, PET estimates of myocardial flow reserve successfully differentiated coronary lesions of intermediate severity (50% to 70% and 70% to 90%; 2.4 +/- 0.4 versus 1.8 +/- 0.5, respectively; P = .04). CONCLUSIONS: In patients with coronary artery disease, non-invasive measurements of myocardial blood flow and flow reserve by PET are inversely and nonlinearly related to stenosis severity as defined by quantitative angiography. Importantly, coronary lesions of intermediate severity have a differential flow reserve that decreases as stenosis increases that can be detected noninvasively by PET, thus allowing better definition of the functional importance of known coronary stenosis.     

Semantic memory in Alzheimer's disease.

Patients with Alzheimer's disease have been suggested to have a semantic memory impairment not present in the normal old. This article reviews the performance of Alzheimer patients on tests of various aspects of semantic memory, including word finding, knowledge of the semantic attributes, and associates of concepts, as well as their category membership. The effect that semantic context has on cognitive processes such as lexical and semantic priming and memory encoding is also reviewed. Finally, the ability of theoretical constructs such as implicit memory and automaticity to explain intertask variability in Alzheimer patients' semantic performance is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced miotic response to topical dilute pilocarpine in patients with Alzheimer's disease

To determine whether miotic response to dilute (0.0625%, two drops) topical pilocarpine could be useful in detecting Alzheimer's disease (AD), we assessed the response in 14 AD patients and 10 control subjects. The miotic response to pilocarpine was significantly greater in AD patients than in control subjects (p < 0.001). In contrast, mydriatic response to the anticholinergic tropicamide (0.01%, one drop) failed to show a difference between the groups (p = 0.54). There was no significant correlation between the miotic and mydriatic responses in individuals. We conclude that dilute pilocarpine could be useful as a diagnostic tool in early AD.