⁃ 1\. Group 1: cognitively and neurologically normal subjects (CN, n=25)

• Male or female ≥ 18 years of age currently enrolled in UNICORN (IRB #842873)

• Cognitively and neurologically normal according to one of the following criteria:

• i. Mini-Mental Status Exam (MMSE; Folstein et al., 1975) score \> 27, OR ii. Montreal Cognitive Assessment (MoCA; Carson et al., 2017; Nasreddine et al., 2005) score \> 25, OR iii. Global Clinical Dementia Rating of 0, OR iv. Evaluation by a trained clinician

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• No history of early-onset neurodegenerative disease in biological siblings or parents, based on the investigators' assessment of the participant's self-reported history.

⁃ 2\. Group 2: non-amnestic Alzheimer's disease (naAD, n=15)

• Male or female ≥ 18 years of age currently enrolled in UNICORN (IRB #842873)

• Clinically diagnosed by a trained clinician as having logopenic-variant primary progressive aphasia (lvPPA) or posterior cortical atrophy (PCA).

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.

⁃ 3\. Group 3: FTLD likely due to tau (FTLD-tau, n=25)

• Male or female ≥ 18 years of age currently enrolled in UNICORN (IRB #842873)

• Clinically diagnosed by a trained clinician as having progressive supranuclear palsy (PSP), non-fluent agrammatic primary progressive aphasia (naPPA), or behavioral-variant frontotemporal dementia (bvFTD) consistent with Pick's disease.

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.

⁃ 4\. Group 4: FTLD likely due to TDP-43 (FTLD-TDP, n=12)

• Male or female ≥ 18 years of age currently enrolled in UNICORN (IRB #842873)

• Clinically diagnosed by a trained clinician as having amyotrophic lateral sclerosis with frontotemporal dementia (ALS-FTD) or semantic-variant primary progressive aphasia (svPPA).

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.

• Group 5: having a known genetic mutation associated with FTLD-tau (genetic FTLD-tau, n=12)

⁃ 1\. Male or female ≥ 18 years of age 2. Currently enrolled in UNICORN (IRB #842873) with a genetic test result indicating a mutation in the MAPT gene.

⁃ 3\. Clinically diagnosed by a trained clinician as having an appropriate neurodegenerative condition OR confirmed as an asymptomatic mutation carrier.

⁃ 4\. Not clinically depressed, according to one of the following criteria: i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician 5. Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.

⁃ 6\. Group 6: having a known genetic mutation associated with FTLD-TDP (genetic FTLD-TDP, n=3)

• Male or female ≥ 18 years of age

• Currently enrolled in UNICORN (IRB #842873) with a genetic test result indicating a mutation in the GRN gene or in open reading frame 72 of chromosome 9 (C9orf72).

• Clinically diagnosed by a trained clinician as having an appropriate neurodegenerative condition OR confirmed as an asymptomatic mutation carrier.

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.

⁃ 7\. Group 7: amnestic Alzheimer's disease (naAD, n=15)

• Male or female ≥ 18 years of age currently enrolled in UNICORN (IRB #842873)

• Clinically diagnosed by a trained clinician as having amnestic mild cognitive impairment (MCI) or amnestic Alzheimer's disease (aAD).

• Not clinically depressed, according to one of the following criteria:

• i. Geriatric Depression scale ≤ 6 (assessed ≤ 6 months prior to study enrollment), OR ii. Evaluation by a trained clinician

• Have a study partner and LAR (if applicable) who can participate as outlined in the protocol. Please see page 15 for further clarification.