INS NYC 2024 Program

Poster	Poster Session 06 Program Schedule 02/15/2024 04:00 pm - 05:15 pm Room: Shubert Complex (Posters 1-60) Poster Session 06: Aging \| MCI \| Neurodegenerative Disease - PART 2 Final Abstract #47 Direct Access to Episodic Memories is Lower in Healthy Middle-Aged to Older Adult Apolipoprotein E4 Carriers Compared to Non-Carriers Aubrey Knoff, University of Arizona, Tucson, United States Bailey Bowles, University of Arizona, Tucson, United States Jessica Andrews-Hanna, University of Arizona, Tucson, United States Matthew Grilli, University of Arizona, Tucson, United States Category: Aging Keyword 1: aging disorders Keyword 2: apolipoprotein E Keyword 3: cognitive functioning Objective: Healthy carriers of the Apolipoprotein E4 (APOE4) allele, which is associated with higher risk for AD dementia, show differences in memory for specific or “episodic” personal experiences (i.e., autobiographical memory) even when neuropsychological testing is within normal limits. Reconstructing specific autobiographical memories is thought to rely upon regions in the default mode network (DMN) and can be executed through either a rapid process (i.e., direct retrieval) that is thought to recruit hippocampal resources or an iterative process using semantic memory (i.e., generative retrieval) that relies upon the interaction between anterior cortical and medial temporal lobe regions. Given that AD and associated risk factors can place increased burden on the DMN, we hypothesized that APOE4 carriers would engage in direct retrieval of specific autobiographical events less often compared to non-carriers, and that they would be less successful at retrieving specific memories using generative retrieval. Participants and Methods: Thirty-nine APOE4 carrier and forty-five age-, education and gender-matched non-carriers (age 60-80) participated in an autobiographical memory study. They were independent in activities of daily living, without neurological conditions that could affect cognition, and scored within a clinically normal range on a battery of neuropsychological tests assessing processing speed, executive function, language, and memory. Participants generated specific autobiographical events in response to 20 concrete noun cues by speaking aloud their retrieval thought process. We categorized each thought process as either a direct or generative retrieval and computed the number of memories retrieved during generative retrievals to assess efficiency. Finally, we correlated direct retrieval rates with delayed spontaneous recall scores from the CVLT-II given the possible reliance upon hippocampal processes, and generative retrieval rates with time to completion scores from Trail Making Test Parts A and B due to the potential contribution of speed and executive function. Results: Only direct retrieval rates were significantly lower (p = .04, d = 0.45), in the APOE4 carriers (M = 0.21, SD = .18) compared to non-carriers (M = 0.29, SD = .16), as successful generative retrieval rates (p = .50, d = 0.15) and efficiency (p = .15, d = 0.32) did not demonstrate significant group differences. Across the sample, episodic memory performance on the CVLT-II positively correlated with direct retrieval rates (r = .24, p = .03). Successful generative retrieval rates did not significantly correlate with the Trail Making Test A measure of processing speed (r = -.09, p = .43) or the Trail Making Test B measure of executive function (r = -.0002, p = .998). There were no significant interactions with APOE4 status in these relationships. Conclusions: Compared to non-carriers, otherwise healthy middle-aged to older adult APOE4 carriers demonstrated a selective difficulty with rapidly reconstructing specific autobiographical events without the support of semantic memory. These findings supplement prior work that suggests many aspects of autobiographical memory are vulnerable to AD-related risk factors and have the potential to identify individuals at risk for future cognitive decline. Future, longitudinal work is critical to track whether direct retrieval abilities predict cognitive decline on standard neuropsychological tests and accumulation of AD-related neuropathology.

Poster

02/15/2024
04:00 pm - 05:15 pm
Room: Shubert Complex (Posters 1-60)

Poster Session 06: Aging | MCI | Neurodegenerative Disease - PART 2

Final Abstract #47

Direct Access to Episodic Memories is Lower in Healthy Middle-Aged to Older Adult Apolipoprotein E4 Carriers Compared to Non-Carriers

Aubrey Knoff, University of Arizona, Tucson, United States
Bailey Bowles, University of Arizona, Tucson, United States
Jessica Andrews-Hanna, University of Arizona, Tucson, United States
Matthew Grilli, University of Arizona, Tucson, United States

Category: Aging

Keyword 1: aging disorders
Keyword 2: apolipoprotein E
Keyword 3: cognitive functioning

Objective:

Healthy carriers of the Apolipoprotein E4 (APOE4) allele, which is associated with higher risk for AD dementia, show differences in memory for specific or “episodic” personal experiences (i.e., autobiographical memory) even when neuropsychological testing is within normal limits. Reconstructing specific autobiographical memories is thought to rely upon regions in the default mode network (DMN) and can be executed through either a rapid process (i.e., direct retrieval) that is thought to recruit hippocampal resources or an iterative process using semantic memory (i.e., generative retrieval) that relies upon the interaction between anterior cortical and medial temporal lobe regions. Given that AD and associated risk factors can place increased burden on the DMN, we hypothesized that APOE4 carriers would engage in direct retrieval of specific autobiographical events less often compared to non-carriers, and that they would be less successful at retrieving specific memories using generative retrieval.

Participants and Methods:

Thirty-nine APOE4 carrier and forty-five age-, education and gender-matched non-carriers (age 60-80) participated in an autobiographical memory study. They were independent in activities of daily living, without neurological conditions that could affect cognition, and scored within a clinically normal range on a battery of neuropsychological tests assessing processing speed, executive function, language, and memory. Participants generated specific autobiographical events in response to 20 concrete noun cues by speaking aloud their retrieval thought process. We categorized each thought process as either a direct or generative retrieval and computed the number of memories retrieved during generative retrievals to assess efficiency. Finally, we correlated direct retrieval rates with delayed spontaneous recall scores from the CVLT-II given the possible reliance upon hippocampal processes, and generative retrieval rates with time to completion scores from Trail Making Test Parts A and B due to the potential contribution of speed and executive function.

Results:

Only direct retrieval rates were significantly lower (p = .04, d = 0.45), in the APOE4 carriers (M = 0.21, SD = .18) compared to non-carriers (M = 0.29, SD = .16), as successful generative retrieval rates (p = .50, d = 0.15) and efficiency (p = .15, d = 0.32) did not demonstrate significant group differences. Across the sample, episodic memory performance on the CVLT-II positively correlated with direct retrieval rates (r = .24, p = .03). Successful generative retrieval rates did not significantly correlate with the Trail Making Test A measure of processing speed (r = -.09, p = .43) or the Trail Making Test B measure of executive function (r = -.0002, p = .998). There were no significant interactions with APOE4 status in these relationships.

Conclusions:

Compared to non-carriers, otherwise healthy middle-aged to older adult APOE4 carriers demonstrated a selective difficulty with rapidly reconstructing specific autobiographical events without the support of semantic memory. These findings supplement prior work that suggests many aspects of autobiographical memory are vulnerable to AD-related risk factors and have the potential to identify individuals at risk for future cognitive decline. Future, longitudinal work is critical to track whether direct retrieval abilities predict cognitive decline on standard neuropsychological tests and accumulation of AD-related neuropathology.