System 1 and 2
In recent years, psychologists have proposed that there are two systems of the mind: System 1 and System 2. The brain is not literally divided like this, but it is a useful analogy.
System 1 is our faster, automatic, intuitive and emotional mode of thinking, while System 2 is slower, more effortful, and deliberate. Most of our daily decisions are made automatically and unconsciously using our System 1. We use our more logical System 2 for decisions we have to consciously make, but this is a limited resource that is easily depleted as we get tired.
For example, shoppers processing their environment through their System 1 are more likely to be engaged by brand names, colours, flashy offers and other emotional appeals. On the other hand, customers with System 2 thinking pay closer attention to product descriptions, meticulously compare products and take their time to make a buying decision.