The aim of the study is to examine the efficacy of supplementing sub-optimal ambient room lighting with a task lamp on working memory and procedural learning.

Inclusion Criteria:

• Aged between 18-30 years;
• Healthy (no medical, psychiatric or sleep disorders;
• Non-smoking for at least 6 months;
• Body Mass Index of >18 or <30 kg/m2;
• Able to maintain 7-hour consistent sleep schedule during the study
• Able to refrain from caffeine, alcohol, medication and supplements during the study

Exclusion Criteria:

• History of alcohol or substance abuse;
• positive result on drugs of abuse urine toxicology;
• Current or past history of sleep disorders, including but not limited to obstructive sleep apnea, narcolepsy, insomnia, or any significant sleep complaint
• Psychiatric disorder, or first degree relative with a psychiatric disorder
• Recent acute or chronic medical disorder
• Use of drugs or medication (birth control OK) likely to affect sleep, alertness or light sensitivity, as determined by the investigators
• Visual disorder, including but not limited to color blindness, or family history of glaucoma
• Pregnancy or lactation
• Shift work (> 2 nights / week in the last 3 months and not during the study)
• Transmeridian travel (2 or more time zones) in the past 3 months
• Any other reason as determine by the Principal Investigator