At the Planète Sauvage in Port-Saint-Père, France in 2011 it was observed that captive dolphins were talking in their sleep. While sleep-talking in general can be rather alarming, what made this even stranger was that they weren’t speaking the same dolphin language they speak during their waking hours. Instead they the sounds were closer to a whale language!
For their entire lives, these dolphins were raised in captivity and so it was not possible for any of these dolphins to have met a whale, let alone learn how to speak in the same tongue.
The dolphins spend much of the time during their days performing in shows aimed at educating the audience about dolphins. At the
beginning of these shows there is an audio montage including sounds of the sea such as seagulls, dolphin whistles and whale sounds.
Since this recording was the only time that the dolphins were being exposed to whale sound, it started to seem possible that the sounds the dolphins were making in their sleep was actually them rehearsing the performances in their sleep. The dolphins never made these sounds during the day, close in time to the performances themselves. Why the great difference in time between hearing and replicating the sounds?
These studies have allowed the scientific community to better understand how language and memory relate to each other in aquatic animals and understanding this can also greatly aid in our understanding of the relationship between our own sleep and episodic memory. Episodic memory is another way of describing the memories that you make during the day. At night these memories get integrated into your long-term memory. This is also known as memory integration and this is what makes it possible for you to retain information and as a result
, what allows you to learn a language.
Make sure to get a lot of sleep after your French class at the Alliance Française de Chicago and learn French in your sleep!
Kremers et al. (2011) http://journal.frontiersin.org/article/10.3389/fpsyg.2011.00386/full