Marketing is a discipline that has gained strength over the years. It seeks to obtain information from its customers’ consumption habits through market research to increase sales and create a positive impact on customers. However, knowing the consumer's preference and identifying the emotion generated by being in contact with the product is a titanic task, and that is where we will rely on neuromarketing, which uses data collection directly from the brain. These signals can be used when the need arises to generate an algorithm that can indicate the emotions activated in consumers through the brain's electrical signals. Using diffuse logic and neural networks, we propose an algorithm to identify the feeling of joy. The creation of this algorithm will allow us to perceive and interpret precisely the emotions of the joy of human beings, information that can be very useful in different situations.