Inclusion Criteria:  Be diagnosed by Insomnia Disorder [307.42 (F51.01)]:  A. A predominant complaint of dissatisfaction with sleep quantity or quality, associated with one (or more) of the following symptoms:  Difficulty initiating sleep. (In children, this may manifest as difficulty initiating sleep without caregiver intervention.) Difficulty maintaining sleep, characterized by frequent awakenings or problems returning to sleep after awakenings. (In children, this may manifest as difficulty returning to sleep without caregiver intervention.) Early-morning awakening with inability to return to sleep.  B. The sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, behavioral, or other important areas of functioning.  C. The sleep difficulty occurs at least 3 nights per week.  D. The sleep difficulty is present for at least 3 months.  E. The sleep difficulty occurs despite adequate opportunity for sleep.  F. The insomnia is not better explained by and does not occur exclusively during the course of another sleep-wake disorder (e.g., narcolepsy, a breathing-related sleep disorder, a circadian rhythm sleep-wake disorder, a parasomnia).  G. The insomnia is not attributable to the physiological effects of a substance (e.g., a drug of abuse, a medication).  H. Coexisting mental disorders and medical conditions do not adequately explain the predominant complaint of insomnia.  Exclusion Criteria:  Have another sleep-wake disorder (e.g., narcolepsy, restless leg syndrome, a breathing-related sleep disorder, a circadian sleep-wake rhythm disorder, a parasomnia). Presence of a relevant medical, psychiatric or neurological disorder. Significant visual or motor impairments. History of alcohol or drug abuse or dependence. Caffeine consumption (more than 150mg per day, that is, approximately 3 cups of espresso or a cup of American coffee). Alcohol consumption (more than 250ml per day, that is, around a pint of beer, a glass of wine, or a shot of liquor). Use of medications with stimulant action, except sedatives or hypnotics prescribed for sleep.