In Chapter 5 we become more familiar with the term déjà vu. Almost everyone has experienced déjà vu and we just chalk it up to some weird and mysterious feeling. We've all felt like we are experiencing something that we have already experienced, even though we rationally are aware that this is a new situation. The Lilienfeld text defines déjà vu as the feeling of reliving an experience that's new (p. 180). It is French for "already seen." And more than two-thirds of people report experiencing déjà vu (p. 180). Is there a biological basis for this? It may be an excess of the neurotransmitter dopamine in the temporal lobe. Another explanation is that we don't consciously recall a memory, so we may have already experienced what we see, but we don't remember it. In other words, our minds process information unconsciously (recall the perception chapter and lecture), so it could be explained that we don't know that we have previously noticed something, and processed it, until we notice it for the "first" time! In a non-biological and unscientific explanation, there are others who claim that déjà vu is evidence of people remembering a past life.
Our text also describes a phenomenon called jamais vu. It is best described as the exact opposite of déjà vu. Translated, it means, "never seen." A person feels like he is seeing something for the first time even though he knows that he has seen it before. People who have amnesia or epileptic seizures have reported experiencing jamais vu. It can also be induced in otherwise unaffected people. Try this: say a word repeatedly, like your name, for 60 seconds. Soon, the word will no longer sound familiar. In related experiments, up to 68% of participants have reported experiencing jamais vu.