Final answer:
Brushing hair before shampooing helps remove tangles and dust, and stimulates blood circulation, but it does not decrease blood circulation. Stimulating circulation is, in fact, one of the benefits of brushing your hair.
Step-by-step explanation:
Brushing the hair prior to a shampoo service accomplishes several beneficial things for scalp and hair health. When you brush your hair, you help in removing tangles and removing dust and dirt, which preps the hair for a cleaner wash. Additionally, brushing can help in stimulating blood circulation to the scalp, which is essential for healthy hair growth and scalp health. However, the idea that brushing hair would decrease blood circulation is incorrect, as the act of brushing generally increases blood flow to the scalp.