This study will investigate the effects of acute morphine administration on taste acuity and how much a person eats. It is hypothesized that there will be a dose dependent decrease in taste acuity and dose dependent increase in food intake associated with acute morphine administration. Knowledge from this study will impact the future of feeding behavior and obesity research in the general population. Results will also promote exploration of the long-term effect of opioid abuse on taste acuity and feeding behavior in substance abusing populations.

Inclusion Criteria:

• Healthy adult male and female volunteers
• Ages of 18 to 65

Exclusion Criteria:

• History of drug dependence (including opioid use disorders)
• History of taste dysfunction
• Significant medical or Axis I psychiatric disorder
• Any trauma or surgical procedures to the head or neck region
• Medication or illicit drug more than 4 out of the last 30 days.
• Pregnancy
• Abnormal electrocardiogram findings
• Negative rating of greater than 40% of the foods available for consumption