It was only a matter of time before scientists made their way into our thoughts as well. Researchers in a recent study have shown that retrieving memories of the events from a person’s past may take place quicker than what they previously thought and it is quite possible to interfere with that process. The process of retrieving episodic memory, personal experiences that require revisiting sensory information received in the past, was believed to be a relatively slow process in the brain, taking around half a second.
Using electroencephalography (EEG), which monitors neural activity with a high time resolution, the researchers from the University of Birmingham showed that episodic retrieval starts with a very rapid reactivation of sensory brain areas. The findings provided the first neural evidence for this early sensory activation, and showed that it actually takes between 0.1 and 0.2 seconds to begin recalling the event.
Researcher Dr Simon Hanslmayr explained that semantic memories, such as knowing that Paris is the capital of France, are bound by no specific time or place. A person rarely remembers how or where you first learned of that information. He added that episodic memories, however, are unique events with a unique frame of reference within both space and time. They were thought to require searching within the hippocampus and therefore take a little time, but these findings challenge that belief and illustrate a much more fast-acting response. The study was published in the Journal of Neuroscience.