Déjà Vu and Disorders
Many scientist believe that Déjà Vu is a result of a chemical reaction in the brain, either triggered by sensory input and recalling a memory, like smelling rose perfume and remembering a funeral, or by minor seizures in the temporal lobe of the brain.
Though there is still no indication directly of the cause of Déjà Vu, scientists have been able to document an association between epilepsy that effects the temporal lobe and Déjà Vu. Often, patients with this from of epilepsy will report that they experienced a strong sense of Déjà Vu immediately before the onset of an epileptic attack. Other patients have reported that experienced Déjà Vu while in the midst of seizure activity.
However, 70 percent of people claim to have had a Déjà Vu experience at some point and scientists are not willing to diagnose them all with some form of epilepsy or other brain disorder. However, some will acknowledge that as much as 65 percent of the population has occasional non-pathological epileptic seizures, like the full body muscle jerk as one is falling asleep.
Scientists have also been able to associate Déjà Vu experiences with anxiety and schizophrenia, but argue that the mostly likely cause of Déjà Vu is a mix-up with memory.
This theory is based in the idea that people experiencing Déjà Vu can often not provide details of when they experienced this event, feeling or place before. It is also argued that sometimes the feeling of Déjà Vu itself cannot be explained later. The person who had the feeling may not even been able to explain what it was that they had already seen or done. Scientists argue that this is evidence that the brain is playing tricks on itself.
It has also been argued that Déjà Vu may be a side effect of mind-altering drugs distorting a person’s sense of reality and time. Scientists have been able to replicate Déjà Vu in the laboratory using recreational drugs and pharmaceuticals designed to treat other conditions, like the common cold.
One final theory, though incredibly hard to quantify, is the concept that Déjà Vu is caused by the brain reacting to two different stimuli inputs a fraction of a second apart from one another. In this theory, the concept is raised that perhaps if the optic nerves misfired. One eye provides the brain with an image and the same image is transmitted to the brain with a miniscule delay from the other eye, confusing the brain into thinking that it has experienced this event previously.
This theory though scientifically sound cannot be tested because we do not have the technology to measure brain reactions in the tiny amount of time involved. Any experiment trying to delve into this theory would be hampered by the amount of time it would take researchers to provide duplicate images to the brain and by the subject’s awareness that the delay is occurring.
