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 #42 Examining Age- and Alzheimer’s Disease Risk-Related Performance on a Stimulus Equivalence Task Kylie Kadey, Wayne State University, Detroit, United States Marci DeBrito, Wayne State University, Detroit, United States Sara Kavanaugh, Wayne State University, Detroit, United States Colt Halter, Wayne State University, Detroit, United States Bradley Dixon, Wayne State University, Detroit, United States Allison Moll, Wayne State University, Detroit, United States John Woodard, Wayne State University, Detroit, United States Category: Dementia (Alzheimer's Disease) Keyword 1: computerized neuropsychological testing Keyword 2: memory: normal Keyword 3: dementia - Alzheimer's disease Objective: Stimulus equivalence (SE) paradigms suggest that after training a limited set of arbitrary relations between stimuli, new relations readily emerge without explicit training. SE tasks may be more sensitive to detecting preclinical Alzheimer’s disease (AD) than traditional associative memory tasks, though this application has been scarcely researched. We examined age- and AD risk-related differences in response time (RT) to explicitly trained and implicitly derived stimulus relations during a novel SE task. We predicted that older adults with a family history of AD (OA+) would exhibit slower RT to derived relations than older adults without an AD family history (OA-) and young adults (YA). Participants and Methods: Participants were 31 YA aged 18 to 35 years (71.0% female) and 80 OA aged 65 to 86 years (72.5% female), 37 of whom had an AD family history. Participants were taught two associations (e.g., A-->B and A-->C) using single English language consonants (letter condition) and abstract symbols (symbol condition). They were subsequently asked to identify these two trained relations and four additional derived relations: B-->A and C-->A (symmetry); B-->C and C-->B (transitivity). The median RT to correct responses across six repeated test trials was calculated for each relation type in each condition. A 3x2x3 mixed ANOVA assessed RT differences using group (YA, OA+, and OA-) as a between-subjects factor and stimulus (letters and symbols) and relation (trained, symmetry, and transitivity) as within-subjects factors. Results: Total accuracy on the SE task did not differ between groups (YA=89.2%, OA-=84.3%, and OA+=84.8%), F(2,108)=2.58, p=.080. The three-way interaction between group, stimulus, and relation was not significant, F(4,216)=0.34, p=.85. There was a significant two-way interaction between stimulus and relation, F(2,216)=8.02, p<.001. In the overall sample, participants recalled trained relations faster than the two derived relations and transitivity relations faster than symmetry relations in the letter condition. However, there were no RT differences across relations in the symbol condition. The two-way interaction between relation and group was also significant, F(4,190)=2.49, p=.044. When averaged across stimulus conditions, YA responded significantly faster to trained relations than the two derived relations and faster to symmetry relations than transitivity relations. In contrast, OA- responded quicker to trained versus symmetry relations and showed a trend toward faster RT to trained than transitivity relations, with no differences between the two derived relations. Lastly, OA+ showed no RT differences between any relations. Conclusions: Overall, results suggest that participants are slower to derive new relations than recall trained relations when the stimuli are familiar, but these differences dissipate as task complexity increases for abstract stimuli. YA showed an expected pattern of slower RT as relation complexity increased. In contrast to our prediction, OA- showed equivalently slower performance to both derived relations. However, OA+ responded equally slowly to all relation types, suggesting they struggle to recall even simple relations. Future research should examine performance on this task longitudinally in APOE e4 allele carriers who convert to mild cognitive impairment or AD.

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 #42

Examining Age- and Alzheimer’s Disease Risk-Related Performance on a Stimulus Equivalence Task

Kylie Kadey, Wayne State University, Detroit, United States
Marci DeBrito, Wayne State University, Detroit, United States
Sara Kavanaugh, Wayne State University, Detroit, United States
Colt Halter, Wayne State University, Detroit, United States
Bradley Dixon, Wayne State University, Detroit, United States
Allison Moll, Wayne State University, Detroit, United States
John Woodard, Wayne State University, Detroit, United States

Category: Dementia (Alzheimer's Disease)

Keyword 1: computerized neuropsychological testing
Keyword 2: memory: normal
Keyword 3: dementia - Alzheimer's disease

Objective:

Stimulus equivalence (SE) paradigms suggest that after training a limited set of arbitrary relations between stimuli, new relations readily emerge without explicit training. SE tasks may be more sensitive to detecting preclinical Alzheimer’s disease (AD) than traditional associative memory tasks, though this application has been scarcely researched. We examined age- and AD risk-related differences in response time (RT) to explicitly trained and implicitly derived stimulus relations during a novel SE task. We predicted that older adults with a family history of AD (OA+) would exhibit slower RT to derived relations than older adults without an AD family history (OA-) and young adults (YA).

Participants and Methods:

Participants were 31 YA aged 18 to 35 years (71.0% female) and 80 OA aged 65 to 86 years (72.5% female), 37 of whom had an AD family history. Participants were taught two associations (e.g., A-->B and A-->C) using single English language consonants (letter condition) and abstract symbols (symbol condition). They were subsequently asked to identify these two trained relations and four additional derived relations: B-->A and C-->A (symmetry); B-->C and C-->B (transitivity). The median RT to correct responses across six repeated test trials was calculated for each relation type in each condition. A 3x2x3 mixed ANOVA assessed RT differences using group (YA, OA+, and OA-) as a between-subjects factor and stimulus (letters and symbols) and relation (trained, symmetry, and transitivity) as within-subjects factors.

Results:

Total accuracy on the SE task did not differ between groups (YA=89.2%, OA-=84.3%, and OA+=84.8%), F(2,108)=2.58, p=.080. The three-way interaction between group, stimulus, and relation was not significant, F(4,216)=0.34, p=.85. There was a significant two-way interaction between stimulus and relation, F(2,216)=8.02, p<.001. In the overall sample, participants recalled trained relations faster than the two derived relations and transitivity relations faster than symmetry relations in the letter condition. However, there were no RT differences across relations in the symbol condition. The two-way interaction between relation and group was also significant, F(4,190)=2.49, p=.044. When averaged across stimulus conditions, YA responded significantly faster to trained relations than the two derived relations and faster to symmetry relations than transitivity relations. In contrast, OA- responded quicker to trained versus symmetry relations and showed a trend toward faster RT to trained than transitivity relations, with no differences between the two derived relations. Lastly, OA+ showed no RT differences between any relations.

Conclusions:

Overall, results suggest that participants are slower to derive new relations than recall trained relations when the stimuli are familiar, but these differences dissipate as task complexity increases for abstract stimuli. YA showed an expected pattern of slower RT as relation complexity increased. In contrast to our prediction, OA- showed equivalently slower performance to both derived relations. However, OA+ responded equally slowly to all relation types, suggesting they struggle to recall even simple relations. Future research should examine performance on this task longitudinally in APOE e4 allele carriers who convert to mild cognitive impairment or AD.