Sleep-dependent Learning in Aging

Exp 1: Using neuroimaging, the investigators will consider whether differences in brain areas
engaged during memory encoding contribute to age-related changes in sleep-dependent memory
consolidation for a word-pair learning task.

Exp 2: The investigators will examine the rate of memory decay between encoding and sleep
using two probes of declarative memory (word-pair learning and visuo-spatial learning).

Exp 3: The investigators will provide additional opportunity for encoding of the word-pair
and visuo-spatial learning tasks.

Exp 4: Using neuroimaging, the investigators will examine neural engagement during encoding
and performance following intervals of sleep and wake.

Exp 5: The investigators will examine the rate of decay of motor sequence learning.

Exp 6: The investigators will examine whether enhanced training ('overtraining') improves
sleep-dependent memory consolidation for older adults.

Inclusion Criteria:

- Age 18-75 yrs

- Healthy sleeper

- No diagnosed sleep or neurodegenerative disorder

Exclusion Criteria:

1. Past diagnosis of any sleep disorder or evidence of a sleep disorder as assessed by
self-reported sleep quality assessments, a standardized diagnostic interview, and an
acclimation night of polysomnography. Using acclimation-night polysomnography,
participants will be excluded with an Apnea-Hypopnea Index >15; a Period-Limb Movement
in Sleep index of >15/hr; sleep-onset latency > 45 min (indicative of insomnia); or
sleep efficiency < 80% (see Edinger et al., Sleep, 2004). In cases in which questions
arise regarding a participants' inclusion or sleep records, a practicing neurologist
board-certified in sleep medicine will review the documentation.

2. Past diagnosis neurological illness or head injury

3. Reported average sleep per night < 5 or > 9 hrs

4. Current employment involving shift work or an inability to keep a regular sleep
schedule during the week prior to testing

5. Current use of psychotropic, recreational drugs, or sleep-altering medications (sleep
medications, cold medicines within the past week, clonidine, sympathomimetic
stimulants)

6. Daily caffeine intake of > 4 cups (coffee, tea, colas)

7. Weekly alcohol intake of > 10 cups

8. Pregnancy or < 12 months post-partum

9. History of bipolar disorder, mania, or current evidence of depression as measured by
Beck Depression Inventory score > 25

10. Abnormal sleep (e.g., shift work, travel across >2 time zones within the past 3
months).

11. Diagnosis of any Axis I disorder, neurological illness or head injury (according to
Demographic and Health History form);

12. Score indicative of cognitive dysfunction (subtest scores < 40)

13. Beck Depression Scale score indicative of depression (> 19).

Additionally, individuals will be excluded from magnetic resonance imaging studies (Exps 1,
4) for:

1. Left handed or ambidextrous

2. Claustrophobia

3. Presence of metal (thoroughly screened via questionnaire and metal detector)

4. Pregnancy