Complex sentence: He mentions that a child mind would not be expected as desired by the experimenter (programmer) at the first attempt, the learning process must involve a method of reward and punishment that will select desirable patterns in the mind.
Split into simpler sentences: He mentions that a child mind would not be expected as desired by the experimenter (programmer) at the first attempt. A learning process that involves a method of reward and punishment must be in place that will select desirable patterns in the mind.