What type of neurotransmitter is most associated with drug addiction?

Xiao is gathering research on the number of daily calories people typically consume at various ages. He gathers data about the number of calories eaten by 25 people at each of the following ages: 10, 20, 30, 40, 50, 60, and 70 years

What type of research design is Xiao using? A) continuous B) cross-sectional C) sequential D) longitudinal

The central executive depends most critically on what part of the brain?

a. the hindbrain b. the corpus callosum c. the hypothalamus d. the prefrontal cortex