Subjects must: 
1. Be able to give valid informed consent 
2. Be 18 55 years of age. 
1. Justification: Many neural processes change with age, and these changes could introduce unwanted variability in both behavioral and MRI signals. In addition, the risk of difficult-to-detect medical abnormalities such as silent cerebral infarcts increases with age. 
2. Screening tool: History. Government-issued forms of identification (e.g. driver s license, birth certificate) will be required when participant appears to be out of age range. 
3. Be in good health. 
1. Justification: Many illnesses may alter neural functioning as well as fMRI signals. 
2. Screening tools: Medical Assessment, Medical History and Physical Examination. Medical assessments include: Vital Signs, EKG, oral HIV test, height/weight measurements, urinalysis and blood sample. Tests on the blood sample include CBC, complete metabolic profile, TSH, ESR, STS and HIV (if needed to confirm a positive salivary test for HIV). The following individual laboratory results will independently disqualify individuals: Cholesterol >250 mg/dl, Hemoglobin < 10.5 g/dl, WBC < 2400/microl, LFTs > 3Xnormal, HCG positive, Casual serum glucose > 200 mg/dl, Urine protein > 1+. The MAI will retain discretion to exclude at less extreme values, depending on the clinical presentation. (Serum glucose over 140 mg/dl will be followed up with a fasting serum glucose assessment. Those with fasting glucose below 100 mg/dl may be considered for the protocol. Others will be rejected and referred for work-up.) MAI will make the final judgment on any questionable lab results. 
4. Right-handed. 
1. Justification: Using right-handed individuals will reduce variability in BOLD MRI data. 
2. Screening tool: Edinburgh Handedness Inventory. 
5. Estimated IQ greater than or equal to 85 
1. Justification: Subjects must be able to perform a cognitively challenging task to a high standard. 
2. Screening tool: Wechsler Abbreviated Scale of Intelligence. 

NCT02231892_inc_T18
Person
age
NCT02231892_inc_T19
Value
18 55 years
NCT02231892_inc_T24
Observation
History
NCT02231892_inc_T26
Condition
good health
NCT02231892_inc_T29
Procedure
Medical Assessment
NCT02231892_inc_T30
Observation
Medical History
NCT02231892_inc_T31
Procedure
Physical Examination
NCT02231892_inc_T32
Measurement
Vital Signs
NCT02231892_inc_T33
Procedure
EKG
NCT02231892_inc_T34
Procedure
oral HIV test
NCT02231892_inc_T35
Measurement
height measurement
NCT02231892_inc_T36
Measurement
weight measurement
NCT02231892_inc_T37
Procedure
urinalysis
NCT02231892_inc_T38
Procedure
blood sample
NCT02231892_inc_T39
Procedure
CBC
NCT02231892_inc_T40
Procedure
complete metabolic profile
NCT02231892_inc_T41
Procedure
TSH
NCT02231892_inc_T42
Procedure
ESR
NCT02231892_inc_T43
Procedure
STS
NCT02231892_inc_T44
Procedure
HIV
NCT02231892_inc_T45
Measurement
salivary test for HIV
NCT02231892_inc_T46
Value
positive
NCT02231892_inc_T48
Measurement
Cholesterol
NCT02231892_inc_T49
Value
>250 mg/dl
NCT02231892_inc_T50
Measurement
Hemoglobin
NCT02231892_inc_T51
Value
< 10.5 g/dl
NCT02231892_inc_T52
Measurement
WBC
NCT02231892_inc_T53
Value
< 2400/microl
NCT02231892_inc_T54
Measurement
LFTs
NCT02231892_inc_T55
Value
> 3Xnormal
NCT02231892_inc_T56
Measurement
HCG
NCT02231892_inc_T57
Value
positive
NCT02231892_inc_T58
Measurement
serum glucose
NCT02231892_inc_T59
Value
> 200 mg/dl
NCT02231892_inc_T60
Measurement
Urine protein
NCT02231892_inc_T61
Value
> 1+
NCT02231892_inc_T62
Negation
disqualify
NCT02231892_inc_T63
Scope
Cholesterol >250 mg/dl, Hemoglobin < 10.5 g/dl, WBC < 2400/microl, LFTs > 3Xnormal, HCG positive, Casual serum glucose > 200 mg/dl, Urine protein > 1+
NCT02231892_inc_T66
Measurement
Serum glucose
NCT02231892_inc_T67
Value
over 140 mg/dl
NCT02231892_inc_T68
Procedure
fasting serum glucose assessment
NCT02231892_inc_T69
Scope
Serum glucose over 140 mg/dl
NCT02231892_inc_T70
Condition
Right-handed
NCT02231892_inc_T73
Procedure
Edinburgh Handedness Inventory
NCT02231892_inc_T74
Measurement
Estimated IQ
NCT02231892_inc_T75
Value
greater than or equal to 85
NCT02231892_inc_T77
Procedure
Wechsler Abbreviated Scale of Intelligence