Advocates of the cognitive perspective believe abnormal behavior results from faulty thinking and distorted perceptions

How do researchers ensure that groups of participants are equal before they begin an experiment?

a) They randomly assign participants to groups. b) They measure the dependent variable repeatedly. c) They use independent variables that are correlated with extraneous variables. d) They assign participants who have identified themselves as having control of extraneous variables.

Which statement is true of the incidence of dementia in Parkinson's patients?

a. Dementia is not a symptom of Parkinson's disease. b. All Parkinson's patients develop dementia. c. Dementia occurs in as many as 80% of Parkinson's patients. d. If dementia occurs, it will occur in the early stages of the disease.