Erin was told that her new college roommate had been diagnosed with depression a few years ago. erin then incorrectly perceived her roommate's laughter as phony. this best illustrates the impact of

this best illustrates the impact of perceptual set. Perceptual set is the leaning to notice certain types of sensory data while ignoring others. Per Vernon in 1955, perceptual set works by the perceiver having expectations of certain things an expects certain responses.

Sometimes but itt depends, their is a lot if drugs on campus too so you really can't just say that