Joe decides to study how insects behave in their everyday life. He watches some ladybugs in his back yard, and codes whether they are either living alone, living in groups, or living in pairs. Joe's observational system is based on the use of which of the following?

If a play-by-play announcer describing each pitch during a baseball game fails to notice a naked fan running across the infield, the announcer would be demonstrating

a. perceptual constancy. b. attentional blindness. c. inattentional blindness. d. perceptual set.

Prolonged periods of sadness, feelings of worthlessness and hopelessness, social withdrawal, and cognitive and physical sluggishness best describes which disorder?

A) major depression B) OCD C) bipolar disorder D) DID