Washington, November 19 : Deja vu, the feeling that a present event has happened before in the same way, may occur when specific aspects of a current situation resemble those of any circumstances one has faced in the past, according to a new study report.
Anne M. Cleary, a psychologist at Colorado State University, writes in the report that one gets a strong feeling of familiarity when there is a lot of overlap between the elements of the new and old situations.
"Many parallels between explanations of dej vu and theories of human recognition memory exist. Theories of familiarity-based recognition and the laboratory methods used to study it may be especially useful for elucidating the processes underlying dej vu experiences," she writes in the report.
Cleary describes familiarity-based recognition as an experience when a person feels that the current situation feels familiar, but does not remember when it has happened before: for instance, seeing a familiar man in a store, but not remembering where one knows him from.
She points out that dej vu is believed to be an example of familiarity-based recognition-one is convinced that one recognizes the situation, but is not sure why.
Cleary conducted experiments testing familiarity-based recognition in which participants were given a list of celebrity names, and shown a collection of celebrity photographs a bit later. Some photographs corresponded to the names on the list, while others did not.
She says that the volunteers were asked to identify the celebrities in the photographs, and indicate how likely it was the celebrity's names were on the list they had seen previously.
The researcher observed that the volunteers had a sense of which names they had studied earlier and which they had not, even when they were unable to identify a celebrity by photo.
She says that the participants could not identify the source of their familiarity with the celebrity, but they knew the celebrity was familiar to them.
Even when famous places like Stonehenge and the Taj Majal were substituted for celebrities, Cleary got similar results.
Those observations suggested that the study's subjects stored a little bit of the memory, according to the report, but it was hazy and that is why they were unable to connect it to the new experience.
Cleary also conducted experiments to see what features or elements of situations could trigger feelings of familiarity, and made participants study a random list of words for the purpose. Some of the words resembled the earlier words in sound (e.g. lady sounds similar to eighty).
She observed that the volunteers reported a sense of familiarity for the new words, even when they could not recall the earlier-presented, similar-sounding words that were the source of this familiarity.
Referring to studies conducted in the past, the researcher pointed out that people might feel familiarity when shown a visual fragment containing isolated geometric shapes from an earlier experience, which suggested that familiar geometric shapes might create the sense that an entire new scene has been viewed before.
Cleary says that the findings support the proposition that events and episodes one experiences are stored in one's memory as individual elements or fragments of that event, and that dej vu may occur when specific aspects of a current situation resemble certain aspects of previously occurring situations.
Her study report has been published in Current Directions in Psychological Science, a journal of the Association for Psychological Science.