For almost a year, a friend has felt worried, irritable, and uneasy, although he does not feel threatened by anything specific. In addition, his muscles seem tense, he feels fatigued, and he is having problems sleeping

Suppose you wanted to replicate some of the research carried out by B. F. Skinner. When deciding on a behavior to measure, it is most likely that you would choose the

a. time it takes to run a maze. b. number of drops of saliva that are secreted. c. probability that a given response will occur. d. changes in a research participant's thoughts.

Nora has had hearing defects since she was a child. She is now 43 and a new procedure to regenerate hair cells in the auditory canal has helped her to have those hearing defects corrected. What most likely occurred in Nora's brain as a result?

a) Not much; she was too old to have much brain plasticity. b) Areas of her brain involved in sound perception changed noticeably. c) Auditory signals were rerouted to the better functioning visual cortex. d) Broca's area had trouble interpreting all the new sounds.