The term "reptilian brain" is often used to refer to the oldest part of the human brain, which is responsible for basic survival functions such as breathing, hunger, thirst, sexuality and fight or flight. This part of the brain is also known as the brain stem or archaic brain.

In neuroweb design, knowledge of the reptilian brain can be used to achieve more effective communication with users. Since the reptilian brain is responsible for basic survival instincts, designing websites and content that appeal to these instincts can help increase user attention and engagement.

For example, highlighting important information or calls to action through the use of eye-catching colours or visual elements can help to grab the attention of users' reptilian brains and encourage them to act on this information. Clear and simple navigation on the website can also help users find what they are looking for quickly and easily, appealing to the brain's survival instinct.

By taking the needs of the reptilian brain into account when designing websites, designers can ensure that the user experience is more effective and satisfying. Using colours, shapes, textures and other visual elements that appeal to the reptilian brain can help users identify more strongly with the website, leading to a higher conversion rate and stronger brand loyalty.