Functional Changes in Brain Activity During Priming in Alzheimer's Disease

2000 ◽  
Vol 12 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Lars Backman ◽  
Ove Almkvist ◽  
Lars Nyberg ◽  
Jesper Andersson
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Activity ◽  
Occipital Cortex ◽  
Neuronal Population ◽  
Stem Completion ◽  
Initial Stimulus ◽  
Functional Changes ◽  
Positron Emission ◽  
Word Stem Completion

Patients with Alzheimer's disease (AD) are often impaired on certain forms of implicit memory, such as word-stem completion priming (WSCP). Lesion data suggest that deficient WSCP may be associated with abnormal functioning in the posterior neocortex. Using positron emission tomography (PET), we here provide direct support for this view. Compared with normal old adults, AD patients showed reduced priming on a word-stem completion task. The normal old showed decreased activity in right occipital cortex (area 19), whereas the AD patients showed increased activity in this region during priming. To the extent that decreased activity during priming reflects an experience-dependent reduction of the neuronal population involved, these results indicate that shaping of the relevant neurons is slower in AD, possibly as a result of inadequate initial-stimulus processing.

scholarly journals Az Alzheimer-kór molekuláris képi megjelenítése

2019 ◽  
Vol 160 (33) ◽  
pp. 1289-1295 ◽  
Author(s):  
Annamária Albert ◽  
Katalin Borbély
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Morphological Changes ◽  
Emission Tomography ◽  
Clinical Form ◽  
Pittsburgh Compound B ◽  
Metabolic Pattern ◽  
Functional Changes ◽  
Positron Emission ◽  
Β Amyloid

Abstract: The ever-growing average age of the society significantly increases the occurrence of Alzheimer’s disease. The increased prevalence represents considerable social and economic burden, which urges the development of diagnostic and therapeutic methods in the field. The most common cause of dementia is Alzheimer’s disease, the typical histopathological abnormality of which are well known. The detection of functional changes results in the early diagnosis of the disease, which precedes the morphological changes by years. Positron-emission tomography plays an important role in the demonstration of metabolic changes. The glucose metabolic pattern differs significantly in each clinical form of dementia. The most important β-amyloid-binding radiopharmaceuticals that should be highlighted are [11C]Pittsburgh compound B that is widely used in the research and [18F]florbetapir that is commonly approved in diagnostics. Tracers visualising neurofibrillary tangles consisting of tau protein appeared most recently. The development continues; newer and newer radiopharmaceuticals appear. These tracers play an important role in both the research and the diagnostics. Orv Hetil. 2019; 160(33): 1289–1295.

Impaired production priming and intact identification priming in Alzheimer's disease

2001 ◽  
Vol 7 (7) ◽  
pp. 785-794 ◽  
Author(s):  
DEBRA A. FLEISCHMAN ◽  
LAURA A. MONTI ◽  
LISA M. DWORNIK ◽  
TERESA T. MORO ◽  
DAVID A. BENNETT ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Explicit Memory ◽  
Repetition Priming ◽  
Recognition Task ◽  
Naming Task ◽  
Word Naming ◽  
Stem Completion ◽  
Word Stem Completion ◽  
Identification Processes

This study examined the distinction between identification and production processes in repetition priming for 16 patients with Alzheimer's disease (AD) and 16 healthy old control participants (NC). Words were read in three study phases. In three test phases, participants (1) reread studied words, along with unstudied words, in a word-naming task (identification priming); (2) completed 3-letter stems of studied and unstudied words into words in a word-stem completion task (production priming); and (3) answered yes or no to having read studied and unstudied words in a recognition task (explicit memory). Explicit memory and word-stem completion priming were impaired in the AD group compared to the NC group. After correcting for baseline slowing, word-naming priming magnitude did not differ between the groups. The results suggest that the distinction between production and identification processes has promise for explaining the pattern of preservation and failure of repetition priming in AD. (JINS, 2001, 7, 785–794.)

The impact of semantic impairment on word stem completion in Alzheimer's disease

2001 ◽  
Vol 39 (3) ◽  
pp. 302-314 ◽  
Author(s):  
M. Beauregard ◽  
H. Chertkow ◽  
D. Gold ◽  
S. Bergman
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Stem Completion ◽  
Word Stem Completion ◽  
The Impact ◽  
Semantic Impairment

Word-stem completion priming for perceptually and conceptually encoded words in patients with Alzheimer's disease

1997 ◽  
Vol 35 (1) ◽  
pp. 25-35 ◽  
Author(s):  
Debra A Fleischman ◽  
John D.E Gabrieli ◽  
Julie A Rinaldi ◽  
Sheryl L Reminger ◽  
Eliza R Grinnell ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Stem Completion ◽  
Word Stem Completion

Word-stem completion priming in healthy aging and Alzheimer's disease: The effects of age, cognitive status, and encoding.

1999 ◽  
Vol 13 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Debra A. Fleischman ◽  
John D. E. Gabrieli ◽  
David W. Gilley ◽  
Joanna D. Hauser ◽  
Kelly L. Lange ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Aging ◽  
Cognitive Status ◽  
Stem Completion ◽  
Word Stem Completion
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