Cross-sequential research is a combination of a cross-sectional approach and a longitudinal approach

Isaac lost a leg in Afghanistan after an improvised bomb exploded near him. Years later, he still has times when he feels intense pain that he perceives as coming from his missing leg. It is obvious that Isaac

a. is craving the attention of his family and friends. b. is experiencing cramps in the other intact leg. c. is experiencing phantom pain. d. has been faking the pain to avoid working.

Our tendency to see objects as relatively stable and unchanging despite changing sensory information is called perceptual ________

a. reversibility b. constancy c. closure d. coherency