scholarly journals The Potential of Naturalistic Eye Movement Tasks in the Diagnosis of Alzheimer’s Disease: A Review

2021 ◽  
Vol 11 (11) ◽  
pp. 1503
Author(s):  
Megan Rose Readman ◽  
Megan Polden ◽  
Melissa Chloe Gibbs ◽  
Lettie Wareing ◽  
Trevor J. Crawford
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Eye Tracking ◽  
Real Life ◽  
Error Rates ◽  
Healthy Older Adults ◽  
Tracking Tasks ◽  
Current Review

Extensive research has demonstrated that eye-tracking tasks can effectively indicate cognitive impairment. For example, lab-based eye-tracking tasks, such as the antisaccade task, have robustly distinguished between people with Alzheimer’s disease (AD) and healthy older adults. Due to the neurodegeneration associated with AD, people with AD often display extended saccade latencies and increased error rates on eye-tracking tasks. Although the effectiveness of using eye tracking to identify cognitive impairment appears promising, research considering the utility of eye tracking during naturalistic tasks, such as reading, in identifying cognitive impairment is limited. The current review identified 39 articles assessing eye-tracking distinctions between people with AD, mild cognitive impairment (MCI), and healthy controls when completing naturalistic task (reading, real-life simulations, static image search) or a goal-directed task involving naturalistic stimuli. The results revealed that naturalistic tasks show promising biomarkers and distinctions between healthy older adults and AD participants, and therefore show potential to be used for diagnostic and monitoring purposes. However, only twelve articles included MCI participants and assessed the sensitivity of measures to detect cognitive impairment in preclinical stages. In addition, the review revealed inconsistencies within the literature, particularly when assessing reading tasks. We urge researchers to expand on the current literature in this area and strive to assess the robustness and sensitivity of eye-tracking measures in both AD and MCI populations on naturalistic tasks.

Individuals With Mild Cognitive Impairment and Alzheimer's Disease Benefit From Audiovisual Speech Cues and Supportive Sentence Context

2021 ◽  
pp. 1-10
Author(s):  
Alexandre Chauvin ◽  
Shari Baum ◽  
Natalie A. Phillips
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Speech Perception ◽  
Sentence Context ◽  
Speech Perception In Noise ◽  
Healthy Older Adults ◽  
Speech Cues

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.

Speech Errors in Alzheimer's Disease

2001 ◽  
Vol 44 (5) ◽  
pp. 1069-1082 ◽  
Author(s):  
Lori J. P. Altmann ◽  
Daniel Kempler ◽  
Elaine S. Andersen
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Error Rates ◽  
Transitive Verb ◽  
Healthy Older Adults ◽  
Speech Output ◽  
Closed Class ◽  
Highly Correlated ◽  
Grammatical Sentence

Researchers studying the speech of individuals with probable Alzheimer's disease (PAD) report that morphosyntax is preserved relative to lexical aspects of speech. The current study questions whether dividing all errors into only two categories, morphosyntactic and lexical, is warranted, given the theoretical controversies concerning the production and representation of pronouns and closed-class words in particular. Two experiments compare the speech output of 10 individuals with Alzheimer's disease to that of 15 healthy age- and education-matched speakers. Results of the first experiment indicate that the pattern of errors in the speech of participants with mild PAD reflects an across-the-board increase in the same types of errors made by healthy older speakers, including closed-class and morphosyntactic errors. In the second task, participants produced a grammatical sentence from written stimuli consisting of a transitive verb and two nouns. Only adults with Alzheimer's disease had difficulties with this task, producing many more closed-class word errors than did healthy older adults. Three of the participants with PAD produced nearly agrammatic speech in this task. These 3 people did not differ from the rest of the PAD group in age, education, working memory, or degree of semantic impairment. Further, error rates on the two tasks were highly correlated. We conclude that morphosyntax is not preserved in the speech output of individuals with PAD, but is vulnerable to errors along with all aspects of language that must be generated by the speaker. We suggest that these results best support a model of speech production in which all words are represented by semantic and grammatical features, both of which are vulnerable to failures of activation when there is damage or noise in the system as a result of pathology, trauma, or even divided attention.

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