Studies of electrical intracranial self-stimulation have influenced the development of biopsychological theories of addiction by indicating that
A) the rewarding effects of drugs play a major role in addiction.
B) there are particular areas of the brain that mediate the experience of pleasure.
C) drug withdrawal and drug pleasure are opposite processes.
D) there are particular areas of the brain that mediate pleasure from drugs.
E) the brain mediates pleasure.
Question 2
The early physical-dependence theories of drug addiction were discredited by the observation that
A) detoxified addicts almost always return to their drug-taking habits.
B) if addicts withdraw over a long period, withdrawal symptoms are more severe.
C) drug addicts who are kept from using drugs for a year or more almost always permanently kick the habit.
D) both A and B
E) both B and C
Photograph illustrating the development of a fetus
Hormonal Control of Development of the Internal Sex Organs
Embryo and fetal development during weeks 1–25 of gestation.
Fetal development from 1 month to 9 months
Development Accounting
Early stages of embryonic development in Drosophila