INS NYC 2024 Program

Poster	Poster Session 04 Program Schedule 02/15/2024 12:00 pm - 01:15 pm Room: Shubert Complex (Posters 1-60) Poster Session 04: Neuroimaging \| Neurostimulation/Neuromodulation \| Teleneuropsychology/Technology Final Abstract #7 Associations Between Episodic Memory and Hippocampal Volume in Late Adulthood Sarah Aghjayan, University of Pittsburgh, Pittsburgh, United States Sarah Polk, Max Planck Institute for Human Development, Berlin, Germany Hayley Ripperger, University of Pittsburgh, Pittsburgh, United States Haiqing Huang, AdventHealth, Orlando, United States Thomas Kamarck, University of Pittsburgh, Pittsburgh, United States Anna Marsland, University of Pittsburgh, Pittsburgh, United States Chaeryon Kang, University of Pittsburgh, Pittsburgh, United States Michelle Voss, University of Iowa, Iowa City, United States Lu Wan, University of Pittsburgh, Pittsburgh, United States Jeffrey Burns, University of Kansas Medical Center, Kansas City, United States Eric Vidoni, University of Kansas Medical Center, Kansas City, United States Edward McAuley, University of Illinois, Champaign, United States Charles Hillman, Northeastern University, Boston, United States Arthur Kramer, Northeastern University, Boston, United States Kirk Erickson, AdventHealth, Orlando, United States Category: Assessment/Psychometrics/Methods (Adult) Keyword 1: neuroimaging: structural Keyword 2: neuropsychological assessment Keyword 3: hippocampus Objective: Various episodic memory tasks employed in neuropsychological settings do not place equivalent demands on the hippocampus and do not differentially reflect hippocampal volume degeneration – one of the strongest predictors of Alzheimer’s disease. Subsequently, it is unclear whether variation in performance on episodic memory measures is a meaningful indicator of risk for developing Alzheimer’s disease. This might be explained by the many ways episodic memory is conceptualized and assessed. In fact, different tasks designed to assess episodic memory are only modestly correlated with each other among older adults with and without cognitive impairment. This suggests that episodic memory might not be a unitary construct in this population. This study examined the distinctiveness of episodic memory tasks and assessed whether they differentially related to hippocampal volume before clinically observable cognitive deficits are present. We predicted that there would be four subfactors of episodic memory (verbal immediate recall, verbal delayed recall, visuospatial, and recognition), and that the verbal delayed recall component would explain the most variance in hippocampal volume among older adults. Further, given that the various hippocampal subfields perform different computations during episodic memory tasks, this study explored whether the episodic memory factors are equivalently associated with all subfield volumes. Participants and Methods: This study examined 648 healthy older adults (M=69.88±3.75). Episodic memory was assessed using seven of the most commonly used tasks in neuropsychological testing settings. Automated Segmentation of Hippocampal Subfields was used to segment the hippocampus. A confirmatory factor analysis was employed with residual covariances included and loadings freely estimated. Hierarchical regression models were used to test the associations between the observed factors of episodic memory and hippocampal volume. Results: A model with three first-order subfactors (verbal immediate recall, verbal delayed recall, and visuospatial) derived from a second-order general episodic memory domain factor had the best model fit (CFI=0.998, RMSEA=0.025, SRMR=0.018, X²(28)=38.93, p=0.08). All three subfactors and the general episodic memory domain factor was significantly associated with total, left, and right hippocampal volume (all p’s <.016). In addition, all subfactors were significantly associated with CA1, entorhinal cortex, and subiculum volume. Only the verbal immediate recall and verbal delayed recall subfactors were significantly associated with CA3 volume. None of the three subfactors were significantly associated with CA2 or dentate gyrus volume. Conclusions: These results suggest that traditional episodic memory tasks are capturing the same overarching construct, but various task conditions tap into different complex processes associated with episodic memory. Performance across the observed factors accounted for less than 3% of the variance in hippocampal volume. Lastly, we find that different hippocampal subfields may not be purely responsible for any singular aspect of episodic memory processing as previous research suggests, but rather they may be preferentially important for various processes. Overall, our results suggest that the link between hippocampal morphology and episodic memory performance in cognitively healthy older adults is weak, and that the association might be more apparent when examining adults with clear episodic memory deficits or using measures other than hippocampal morphology.

Poster

02/15/2024
12:00 pm - 01:15 pm
Room: Shubert Complex (Posters 1-60)

Poster Session 04: Neuroimaging | Neurostimulation/Neuromodulation | Teleneuropsychology/Technology

Final Abstract #7

Associations Between Episodic Memory and Hippocampal Volume in Late Adulthood

Sarah Aghjayan, University of Pittsburgh, Pittsburgh, United States
Sarah Polk, Max Planck Institute for Human Development, Berlin, Germany
Hayley Ripperger, University of Pittsburgh, Pittsburgh, United States
Haiqing Huang, AdventHealth, Orlando, United States
Thomas Kamarck, University of Pittsburgh, Pittsburgh, United States
Anna Marsland, University of Pittsburgh, Pittsburgh, United States
Chaeryon Kang, University of Pittsburgh, Pittsburgh, United States
Michelle Voss, University of Iowa, Iowa City, United States
Lu Wan, University of Pittsburgh, Pittsburgh, United States
Jeffrey Burns, University of Kansas Medical Center, Kansas City, United States
Eric Vidoni, University of Kansas Medical Center, Kansas City, United States
Edward McAuley, University of Illinois, Champaign, United States
Charles Hillman, Northeastern University, Boston, United States
Arthur Kramer, Northeastern University, Boston, United States
Kirk Erickson, AdventHealth, Orlando, United States

Category: Assessment/Psychometrics/Methods (Adult)

Keyword 1: neuroimaging: structural
Keyword 2: neuropsychological assessment
Keyword 3: hippocampus

Objective:

Various episodic memory tasks employed in neuropsychological settings do not place equivalent demands on the hippocampus and do not differentially reflect hippocampal volume degeneration – one of the strongest predictors of Alzheimer’s disease. Subsequently, it is unclear whether variation in performance on episodic memory measures is a meaningful indicator of risk for developing Alzheimer’s disease. This might be explained by the many ways episodic memory is conceptualized and assessed. In fact, different tasks designed to assess episodic memory are only modestly correlated with each other among older adults with and without cognitive impairment. This suggests that episodic memory might not be a unitary construct in this population. This study examined the distinctiveness of episodic memory tasks and assessed whether they differentially related to hippocampal volume before clinically observable cognitive deficits are present. We predicted that there would be four subfactors of episodic memory (verbal immediate recall, verbal delayed recall, visuospatial, and recognition), and that the verbal delayed recall component would explain the most variance in hippocampal volume among older adults. Further, given that the various hippocampal subfields perform different computations during episodic memory tasks, this study explored whether the episodic memory factors are equivalently associated with all subfield volumes.

Participants and Methods:

This study examined 648 healthy older adults (M=69.88±3.75). Episodic memory was assessed using seven of the most commonly used tasks in neuropsychological testing settings. Automated Segmentation of Hippocampal Subfields was used to segment the hippocampus. A confirmatory factor analysis was employed with residual covariances included and loadings freely estimated. Hierarchical regression models were used to test the associations between the observed factors of episodic memory and hippocampal volume.

Results:

A model with three first-order subfactors (verbal immediate recall, verbal delayed recall, and visuospatial) derived from a second-order general episodic memory domain factor had the best model fit (CFI=0.998, RMSEA=0.025, SRMR=0.018, X²(28)=38.93, p=0.08). All three subfactors and the general episodic memory domain factor was significantly associated with total, left, and right hippocampal volume (all p’s <.016). In addition, all subfactors were significantly associated with CA1, entorhinal cortex, and subiculum volume. Only the verbal immediate recall and verbal delayed recall subfactors were significantly associated with CA3 volume. None of the three subfactors were significantly associated with CA2 or dentate gyrus volume.

Conclusions:

These results suggest that traditional episodic memory tasks are capturing the same overarching construct, but various task conditions tap into different complex processes associated with episodic memory. Performance across the observed factors accounted for less than 3% of the variance in hippocampal volume. Lastly, we find that different hippocampal subfields may not be purely responsible for any singular aspect of episodic memory processing as previous research suggests, but rather they may be preferentially important for various processes. Overall, our results suggest that the link between hippocampal morphology and episodic memory performance in cognitively healthy older adults is weak, and that the association might be more apparent when examining adults with clear episodic memory deficits or using measures other than hippocampal morphology.