INS NYC 2024 Program

Poster	Poster Session 02 Program Schedule 02/15/2024 08:00 am - 09:15 am Room: Shubert Complex (Posters 1-60) Poster Session 02: Aging \| MCI \| Neurodegenerative Disease - PART 1 Final Abstract #49 Neural Correlates of Working Memory Load in Older Adults with Mild Cognitive Impairment Youssef Khattab, VA Greater Los Angeles Healthcare System, Los Angeles, United States Kelsey Holiday, VA Greater Los Angeles Healthcare System, Los Angeles, United States Amy Jimenez, VA Greater Los Angeles Healthcare System, Los Angeles, United States Mario Mendez, VA Greater Los Angeles Healthcare System, Los Angeles, United States Rebecca Melrose, VA Greater Los Angeles Healthcare System, Los Angeles, United States Category: MCI (Mild Cognitive Impairment) Keyword 1: neuroimaging: functional Keyword 2: mild cognitive impairment Keyword 3: aging disorders Objective: Working memory is crucial for planning and problem solving in daily life, yet it is susceptible to decline as people age. Previous research has associated working memory deficits with increased activation in the anterior and posterior cingulate cortex (PCC) in Mild Cognitive Impairment (MCI) relative to controls (Zanchi et al., 2017). There is considerable debate regarding whether people are accurately able to detect these subtle changes in working memory. This current study seeks to understand the structural and functional activation of working memory processing and examine their role in the self-awareness of executive dysfunction in older individuals who are at risk for dementia. Participants and Methods: Participants were 31 older adults (aged>60) broken down into two groups including Mild Cognitive Impairment (MCI; n= 15) and aging controls (AC; n=16). All Participants completed the n-back task during functional magnetic resonance imaging (fMRI). Cortical thickness was calculated using FreeSurfer and brain activity during the n-back task was analyzed using FSL (p<.01 cluster corrected). Participants also completed the Behavior Rating Inventory of Executive Function Adult version (BRIEF-A) outside the scanner. Group differences in right and left PCC cortical thickness, BREIF-A Metacognition Index (MI) T-scores, and n-back performance were examined using independent samples t-tests. Linear regression analyses between BREIF-A Metacognition Index T-scores and n-back accuracy scores were conducted. Linear regression analyses were also conducted between right and left PCC thickness and n-back accuracy. Results: The groups significantly differed on BRIEF-A Metacognition Index (MI; p=.014) and performance on 1-back (p=.020) and 2-back (p=.030) but not on the 0-back (p=.058), such that AC demonstrated better n-back performance and lower MI scores. The MI scores significantly predicted working memory performance on the 2-back (p=.045) but not 1-back (p=.250) or 0-back (p=.567). Patients with MCI showed hypoactivation of anterior frontal lobe in the 1>0 contrast and showed hyperactivation of PCC in the 2>1 contrast. Likewise, when both working memory conditions were contrasted against the control (1 and 2 back > 0) MCI patients showed hyperactivation of PCC. T-tests revealed significant group differences in left PCC (p=.017) but not right PCC (p=.063) thickness; the control group showed increased cortical thickness in the left PCC compared to MCI group. Left PCC cortical thickness significantly predicted performance on 0-back (p=.003), 1-back (p=.004), and 2-back (p=.044) trials. Conclusions: Findings revealed that people with MCI demonstrated worse performance on the n-back task as the working memory load increased compared to elderly controls, as well as higher report of subjective working memory deficits. Neuroimaging revealed that as working memory load increases in people with MCI, there is a shift towards posterior brain processing. Poorer task performance was also associated with lower PCC thickness, suggesting that left PCC cortical dysregulation may be a biomarker associated with early working memory deficits. Insight into deficits also predicted working memory performance. Taken together this increase in task-based activation is thought to reflect a compensatory mechanism.

Poster

02/15/2024
08:00 am - 09:15 am
Room: Shubert Complex (Posters 1-60)

Poster Session 02: Aging | MCI | Neurodegenerative Disease - PART 1

Final Abstract #49

Neural Correlates of Working Memory Load in Older Adults with Mild Cognitive Impairment

Youssef Khattab, VA Greater Los Angeles Healthcare System, Los Angeles, United States
Kelsey Holiday, VA Greater Los Angeles Healthcare System, Los Angeles, United States
Amy Jimenez, VA Greater Los Angeles Healthcare System, Los Angeles, United States
Mario Mendez, VA Greater Los Angeles Healthcare System, Los Angeles, United States
Rebecca Melrose, VA Greater Los Angeles Healthcare System, Los Angeles, United States

Category: MCI (Mild Cognitive Impairment)

Keyword 1: neuroimaging: functional
Keyword 2: mild cognitive impairment
Keyword 3: aging disorders

Objective:

Working memory is crucial for planning and problem solving in daily life, yet it is susceptible to decline as people age. Previous research has associated working memory deficits with increased activation in the anterior and posterior cingulate cortex (PCC) in Mild Cognitive Impairment (MCI) relative to controls (Zanchi et al., 2017). There is considerable debate regarding whether people are accurately able to detect these subtle changes in working memory. This current study seeks to understand the structural and functional activation of working memory processing and examine their role in the self-awareness of executive dysfunction in older individuals who are at risk for dementia.

Participants and Methods:

Participants were 31 older adults (aged>60) broken down into two groups including Mild Cognitive Impairment (MCI; n= 15) and aging controls (AC; n=16). All Participants completed the n-back task during functional magnetic resonance imaging (fMRI). Cortical thickness was calculated using FreeSurfer and brain activity during the n-back task was analyzed using FSL (p<.01 cluster corrected). Participants also completed the Behavior Rating Inventory of Executive Function Adult version (BRIEF-A) outside the scanner. Group differences in right and left PCC cortical thickness, BREIF-A Metacognition Index (MI) T-scores, and n-back performance were examined using independent samples t-tests. Linear regression analyses between BREIF-A Metacognition Index T-scores and n-back accuracy scores were conducted. Linear regression analyses were also conducted between right and left PCC thickness and n-back accuracy.

Results:

The groups significantly differed on BRIEF-A Metacognition Index (MI; p=.014) and performance on 1-back (p=.020) and 2-back (p=.030) but not on the 0-back (p=.058), such that AC demonstrated better n-back performance and lower MI scores. The MI scores significantly predicted working memory performance on the 2-back (p=.045) but not 1-back (p=.250) or 0-back (p=.567). Patients with MCI showed hypoactivation of anterior frontal lobe in the 1>0 contrast and showed hyperactivation of PCC in the 2>1 contrast. Likewise, when both working memory conditions were contrasted against the control (1 and 2 back > 0) MCI patients showed hyperactivation of PCC. T-tests revealed significant group differences in left PCC (p=.017) but not right PCC (p=.063) thickness; the control group showed increased cortical thickness in the left PCC compared to MCI group. Left PCC cortical thickness significantly predicted performance on 0-back (p=.003), 1-back (p=.004), and 2-back (p=.044) trials.

Conclusions:

Findings revealed that people with MCI demonstrated worse performance on the n-back task as the working memory load increased compared to elderly controls, as well as higher report of subjective working memory deficits. Neuroimaging revealed that as working memory load increases in people with MCI, there is a shift towards posterior brain processing. Poorer task performance was also associated with lower PCC thickness, suggesting that left PCC cortical dysregulation may be a biomarker associated with early working memory deficits. Insight into deficits also predicted working memory performance. Taken together this increase in task-based activation is thought to reflect a compensatory mechanism.