The BAADER–MEINHOF EFFECT, also known as frequency illusion, is a cognitive bias and refers to a phenomenon where things or objects that an individual has recently noticed like a name, a word, etc. suddenly seems to appear with strange frequency afterwards. In this phenomenon, the person who has recently paid attention to something obscure or unfamiliar begins to encounter that newly learned information in unanticipated situations. It gives an impression that out of nowhere, the new information is rapidly surrounding him. The reason is that the brain starts noticing the thing, which was once unfamiliar. One interesting thing about this phenomenon is that it is not named after the linguist who did research on it. Rather it is named after a West German militant group which was founded in 1970. However, the militant group has nothing to do with the phenomenon. It was named after the group when a reader of St Paul Pioneer Press first noticed the mention and then randomly heard two references within 24 hours out of nowhere. The phenomenon is a result of two cognitive processes namely selective attention and confirmation bias.
The term JAMAIS VU in psychology is borrowed from the French language and means ‘never seen’ in English. It refers to the phenomenon in which the observer experiences a situation, which is although familiar to him or her, suddenly seems very unfamiliar as if being seen or experienced for the first time. Jamais vu is often described as the opposite of another phenomenon called deja vu, which refers to the feeling of having already experienced what is happening at present. Involving a sense of strangeness, Jamais vu gives the observer an impression of seeing something for the first time in spite of being rationally aware of having seen or been in the situation before. This phenomenon can be easily created by writing or saying a specific word out loud several times. After a few seconds one will feel that the word sounds weird and unfamiliar and that it makes no sense.