Very interesting talk today at Roehampton by Akira O’Connor whose research specialises in deja vu:
60 / 97 people say they experience it. He describes deja vu as a feeling of familiarity with experience that shouldn’t be as familiar as it is. Sometimes interpreted as spiritual.
Often used for film plots.
Earliest descriptions in 19th century based on 2 types of deja vu (illusion & delusion)
Illusion: Boirac – Revue Philosophique 1876
Delusion: Arnaud Société Medico Psychologique 1896 – more scientific definition based on a patient.
More recently Alan Brown 2004 Deja Vu Experience 2004 – clash between 2 opposing mental evaluations. An objective assessment of unfamiliarity juxtaposed with a subjective evaluation of familiarity.
People typically experience dejavu in familiar settings.
Not usually reported before 6-10 yrs old. Seems to peak in 20s then steady decline.
Deja Vu (illusion)
Healthy population – short, not intense, Behaviourally benign
Deja Vecu (delusion)
Clinical population, lasts longer, high intensity and behaviourally significant.
Had participants study stimuli for particular set of characteristics
Research found positive correlation for conflict resolution regions. Anterior singular, medial prefrontal.
Memory error but not sufficient to cause deja vu. Depends on which experience – illusion – something causes signal familiarity that memory being retrieved even if false or just a twitch. Projected to prefrontal cortex.
Dejavecu – delusion – not as widely researched but is memory error and monitoring failure. Maybe age – we get less good at monitoring inconsistencies so don’t get conflict.
Epilepsy – report deja vu then know about to have a seizure.