scholarly journals Do Alzheimer’s Disease Patients Benefit From Prior-Knowledge in Associative Recognition Memory?

2019 ◽  
Vol 25 (04) ◽  
pp. 443-452
Author(s):  
Emma Delhaye ◽  
Adrien Folville ◽  
Isabelle Simoes Loureiro ◽  
Laurent Lefebvre ◽  
Eric Salmon ◽  
...  

AbstractObjectives: Although the influence of prior knowledge on associative memory in healthy aging has received great attention, it has never been studied in Alzheimer’s disease (AD). This study aimed at assessing whether AD patients could benefit from prior knowledge in associative memory and whether such benefit would be related to the integrity of their semantic memory. Methods: Twenty-one AD patients and 21 healthy older adults took part in an associative memory task using semantically related and unrelated word pairs and were also submitted to an evaluation of their semantic memory. Results: While participants of both groups benefited from semantic relatedness in associative discrimination, related pairs recognition was significantly predicted by semantic memory integrity in healthy older adults only. Conclusions: We suggest that patients benefitted from semantic knowledge to improve their performance in the associative memory task, but that such performance is not related to semantic knowledge integrity evaluation measures because the two tasks differ in the way semantic information is accessed: in an automatic manner for the associative memory task, with automatic processes thought to be relatively preserved in AD, and in a controlled manner for the semantic knowledge evaluation, with controlled processes thought to be impaired in AD. (JINS, 2019, 25, 443–452)

2021 ◽  
pp. 1-8
Author(s):  
Bárbara Luzia Covatti Malcorra ◽  
Natália Bezerra Mota ◽  
Janaina Weissheimer ◽  
Lucas Porcello Schilling ◽  
Maximiliano Agustin Wilson ◽  
...  

Connected speech is an everyday activity. We aimed to investigate whether connected speech can differentiate oral narrative production between adults with Alzheimer’s disease (AD; n = 24) and cognitively healthy older adults (n = 48). We used graph attributes analysis to represent connected speech. Participants produced oral narratives and performed semantic, episodic, and working memory tasks. AD patients produced less connected narratives than cognitively healthy older adults. Connectedness was associated with semantic memory in AD and with episodic memory in controls. Word-graphs connectedness represents a practical tool to assess cognitive impairment in AD patients.


2018 ◽  
Vol 16 (1) ◽  
pp. 67-89 ◽  
Author(s):  
Cassandra Morrison ◽  
Sheida Rabipour ◽  
Vanessa Taler ◽  
Christine Sheppard ◽  
Frank Knoefel

Background: Cognitive deficits are correlated with increasing age and become more pronounced for people with mild cognitive impairment (MCI) and dementia caused by Alzheimer’s disease (AD). Conventional methods to diagnose cognitive decline (i.e., neuropsychological testing and clinical judgment) can lead to false positives. Tools such as electroencephalography (EEG) offer more refined, objective measures that index electrophysiological changes associated with healthy aging, MCI, and AD. Objective: We sought to review the EEG literature to determine whether visual event-related potentials (ERPs) can distinguish between healthy aging, MCI, and AD. Method: We searched Medline and PyscInfo for articles published between January 2005 and April 2018. Articles were considered for review if they included participants aged 60+ who were healthy older adults or people with MCI and AD, and examined at least one visually elicited ERP component. Results: Our search revealed 880 records, of which 34 satisfied the inclusion criteria. All studies compared cognitive function between at least two of the three groups (healthy older adults, MCI, and AD). The most consistent findings related to the P100 and the P3b; while the P100 showed no differences between groups, the P3b showed declines in amplitude in MCI and AD. Conclusion: Visually elicited ERPs can offer insight into the cognitive processes that decline in MCI and AD. The P3b may be useful in identifying older adults who may develop MCI and AD, and more research should examine the sensitivity and specificity of this component when diagnosing MCI and AD.


2012 ◽  
Vol 29 (5) ◽  
pp. 501-507 ◽  
Author(s):  
Ashley D. Vanstone ◽  
Ritu Sikka ◽  
Leila Tangness ◽  
Rosalind Sham ◽  
Angeles Garcia ◽  
...  

the present study addressed episodic and semantic memory for melodies in three groups of participants: 35 younger adults, 40 older adults, and 10 individuals with mild to moderate Alzheimer's disease (AD). To assess episodic memory, a study list of eight novel target melodies was presented three times, followed by a test trial in which target melodies were mixed with foil (previously unheard) melodies. Both explicit and implicit measures were obtained. Explicit memory was assessed by the accuracy of discrimination of the target melodies from the foils. Younger adults were significantly more accurate than older adults, who in turn had significantly higher scores than AD adults. Implicit memory was assessed by examining the difference in pleasantness ratings between target and foil melodies. Younger adults showed significantly greater differences in pleasantness ratings than older adults and AD adults; scores for the two latter groups did not differ. To assess semantic memory, participants were asked to identify traditional melodies within a series of traditional and novel melodies. In contrast to the episodic memory results, all three groups showed very high scores on the semantic memory task with no significant differences among groups. The results support the notion that, though other forms of musical memory may be compromised, semantic memory for melody may be preserved in normal aging and in AD.


Author(s):  
Eun Jin Paek ◽  
Si On Yoon

Purpose Speakers adjust referential expressions to the listeners' knowledge while communicating, a phenomenon called “audience design.” While individuals with Alzheimer's disease (AD) show difficulties in discourse production, it is unclear whether they exhibit preserved partner-specific audience design. The current study examined if individuals with AD demonstrate partner-specific audience design skills. Method Ten adults with mild-to-moderate AD and 12 healthy older adults performed a referential communication task with two experimenters (E1 and E2). At first, E1 and participants completed an image-sorting task, allowing them to establish shared labels. Then, during testing, both experimenters were present in the room, and participants described images to either E1 or E2 (randomly alternating). Analyses focused on the number of words participants used to describe each image and whether they reused shared labels. Results During testing, participants in both groups produced shorter descriptions when describing familiar images versus new images, demonstrating their ability to learn novel knowledge. When they described familiar images, healthy older adults modified their expressions depending on the current partner's knowledge, producing shorter expressions and more established labels for the knowledgeable partner (E1) versus the naïve partner (E2), but individuals with AD were less likely to do so. Conclusions The current study revealed that both individuals with AD and the control participants were able to acquire novel knowledge, but individuals with AD tended not to flexibly adjust expressions depending on the partner's knowledge state. Conversational inefficiency and difficulties observed in AD may, in part, stem from disrupted audience design skills.


Author(s):  
Alexandre Chauvin ◽  
Shari Baum ◽  
Natalie A. Phillips

Purpose Speech perception in noise becomes difficult with age but can be facilitated by audiovisual (AV) speech cues and sentence context in healthy older adults. However, individuals with Alzheimer's disease (AD) may present with deficits in AV integration, potentially limiting the extent to which they can benefit from AV cues. This study investigated the benefit of these cues in individuals with mild cognitive impairment (MCI), individuals with AD, and healthy older adult controls. Method This study compared auditory-only and AV speech perception of sentences presented in noise. These sentences had one of two levels of context: high (e.g., “Stir your coffee with a spoon”) and low (e.g., “Bob didn't think about the spoon”). Fourteen older controls ( M age = 72.71 years, SD = 9.39), 13 individuals with MCI ( M age = 79.92 years, SD = 5.52), and nine individuals with probable Alzheimer's-type dementia ( M age = 79.38 years, SD = 3.40) completed the speech perception task and were asked to repeat the terminal word of each sentence. Results All three groups benefited (i.e., identified more terminal words) from AV and sentence context. Individuals with MCI showed a smaller AV benefit compared to controls in low-context conditions, suggesting difficulties with AV integration. Individuals with AD showed a smaller benefit in high-context conditions compared to controls, indicating difficulties with AV integration and context use in AD. Conclusions Individuals with MCI and individuals with AD do benefit from AV speech and semantic context during speech perception in noise (albeit to a lower extent than healthy older adults). This suggests that engaging in face-to-face communication and providing ample context will likely foster more effective communication between patients and caregivers, professionals, and loved ones.


Author(s):  
K.V. Papp ◽  
D.M. Rentz ◽  
P. Maruff ◽  
C.-K. Sun ◽  
R. Raman ◽  
...  

Background: Computerized cognitive assessments may improve Alzheimer’s disease (AD) secondary prevention trial efficiency and accuracy. However, they require validation against standard outcomes and relevant biomarkers. Objective: To assess the feasibility and validity of the tablet-based Computerized Cognitive Composite (C3). Design: Cross-sectional analysis of cognitive screening data from the A4 study (Anti-Amyloid in Asymptomatic AD). Setting: Multi-center international study. Participants: Clinically normal (CN) older adults (65-85; n=4486). Measurements: Participants underwent florbetapir-Positron Emission Tomography for Aβ+/- classification. They completed the C3 and standard paper and pencil measures included in the Preclinical Alzheimer’s Cognitive Composite (PACC). The C3 combines memory measures sensitive to change over time (Cogstate Brief Battery-One Card Learning) and measures shown to be declining early in AD including pattern separation (Behavioral Pattern Separation Test- Object- Lure Discrimination Index) and associative memory (Face Name Associative Memory Exam- Face-Name Matching). C3 acceptability and completion rates were assessed using qualitative and quantitative methods. C3 performance was explored in relation to Aβ+/- groups (n=1323/3163) and PACC. Results: C3 was feasible for CN older adults to complete. Rates of incomplete or invalid administrations were extremely low, even in the bottom quartile of cognitive performers (PACC). C3 was moderately correlated with PACC (r=0.39). Aβ+ performed worse on C3 compared with Aβ- [unadjusted Cohen’s d=-0.22 (95%CI: -0.31,-0.13) p<0.001] and at a magnitude comparable to the PACC [d=-0.32 (95%CI: -0.41,-0.23) p<0.001]. Better C3 performance was observed in younger, more educated, and female participants. Conclusions: These findings provide support for both the feasibility and validity of C3 and computerized cognitive outcomes more generally in AD secondary prevention trials.


Sign in / Sign up

Export Citation Format

Share Document