Skipper does the laundry 25% of the time and washes dishes about 50% of the time. Barbie decides to start praising Skipper for doing the laundry. After that, Skipper begins to do the laundry about 75% of the time. Since that was successful, Barbie decides to try praising Skipper's dish washing, too. Soon, Skipper is washing the dishes 100% of the time. What experimental design was Barbie using?

The functioning of the human brain depends upon cross-talk among _____

A) glial cells. B) neurons. C) nodes of Ranvier. D) reuptake vesicles.

What is one significant reason for the advances in fine motor skills in children six to eight years old?

a) Children live long enough to get more practice with fine motor skills. b) Children's cognitive development is increasing. c) Children have more opportunity to model fine motor skill behavior(s) from others and practice on a consistent basis. d) The amount of myelin in the brain increases to protect, insulate, and surround the nerve cells, raising the speed at which electrical impulses travel between neurons.