The "illusion of truth" refers to the human tendency to judge information as truer when we are exposed to it more often. This phenomenon occurs because our brain perceives information that we hear or read frequently as familiar and therefore more true.

This is important for neuromarketing, as marketers can utilise this tendency to communicate their messages more effectively. By repeatedly presenting their advertising messages and brand messages, they can increase the sense of familiarity among consumers and thus increase the likelihood that they will accept the messages as true. However, it is important to note that this phenomenon can also lead to false information being accepted as true if it is repeated often enough. Therefore, it is important that organisations ensure that their messages are accurate and ethical before presenting them repeatedly.