The statement is FALSE. With well-behaved preferences the substitution effect is always negative: when the price of a good decreases, its consumption will increase. For a normal good, the income effect is always positive, hence has the opposite sign of the substitution effect. Notice that this implies that for normal goods the substitution effect and the income effect move consumption to the same direction: when the price of a good decreases, the consumer's income in real terms increases, and this results in an increase of consumption of the good.