Sleep-dependent Learning in Aging

Inclusion Criteria:

* Age 18-80 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