Throughout her life, comedian Sarah Silverman has experienced varying degrees of depression, which she likens to a "chemical change." She plays a profoundly depressed woman in the film, 'I Smile Back.' Critic at-large John Powers reviews 'Bridge of Spies.' Wildlife photographer Gerrit Vyn and essayist Scott Weidensaul share bird calls and discuss some of the remarkable abilities of birds. Both guests contributed to a new book about North American birds.
