In his mechanistic approach to psychology, Thorndike discarded concepts of satisfaction and discomfort

When a group of individuals is tested in a series of treatment conditions over time, which factor can cause progressive improvement in performance from treatment to treatment and thus provide an alternative explanation for the results?

a. history b. selection bias c. practice d. fatigue

Delta waves are produced during which stages of sleep?

a. Stage 1 and 2 c. Stages 1 and 5 b. Stages 3 and 4 d. all 5 stages