Electrical stimulation of specific neurons can produce pain relief.

During a grade school field trip, Ryan and his friends were running down a hill when he stepped on a snake. He was unharmed but shaken by the experience. When one of his friends mentioned the incident months later, Ryan could not remember running down the

a. sublimation. b. displacement. c. repression. d. regression.

Frida is sitting on a park bench when she hears a police car turn on its siren. Although she cannot see the police car, she is certain that it is nearby. What cue did her brain most likely use to come to this conclusion?

a. the slight energy difference between each ear b. the slight time difference between when the sound reached each ear c. the overall loudness of the sound d. the frequency of the sound