Some of the oldest human arts in Europe are completely hidden from view, hidden in the narrow caves of deep, dark and winding caves.
To see the walls themselves, let alone decorate them, the artists of the Stone Age should have crawled with several torches, and archaeologists now suspect that all the smoke induced a changed state of consciousness.
Hallucinatory plants have already been connected to the extraterrestrial nature of rock art, but this new hypothesis suggests that ancient humans consciously pursued a similar transformative experience in the depths of the underworld long before they began using other psychoactive substances.
The closer they go to the fresh air, experts suggest, the longer the mental journey and the more artistic they become.
“A few years ago, while visiting some decorated caves in France, I began to notice that most of the images are found deep in very narrow caves,” said archaeologist Yafit Kedar of Tel Aviv University in Israel. The Jerusalem Post.
“I began to wonder why they chose to work in this way, unlike the paint at the entrance of the larger caves, where they could have enjoyed natural light.”
Modeling the effect of lamps and lamps on the airflow of a cave, Kedar and her colleagues discovered that the narrower the entrance to a cave, the faster a person will be oxygenated.
In a deep, single-entry cavern, simulations show that oxygen levels can drop below 18 percent in just fifteen minutes, possibly inducing a state of hypoxia if concentrations drop low enough.
In humans, lack of oxygen can naturally release dopamine in the brain, sometimes leading to drowsiness, euphoria, hallucinations or experiences outside the body. In fact, scientists studying caves have reported that they had similar effects even without a lighted torch in their hand.
Additional use of fire makes such a condition much more likely.
In a large cave mouth with open access to the outside world, a burning flame tends to create two distinct layers of air: the lower layer consists of outside air, and the upper layer consists of exhaust gases returning to the outside.
The flow of air in an open cave. (Kedar et al., Journal of Archeology, Consciousness and Culture, 2021)
On the other hand, when the fire burns in a narrow passage, both the upper and lower layers partially mix, which means that the air everywhere carries significantly less oxygen than the 21% we usually breathe.
Moreover, because oxygen atoms are lighter than carbon dioxide, they tend to float upwards, descending from the tunnels of a cave to the entrance. The more someone travels with a burning flame in a cave system, the more likely they are to starve for oxygen.
In various simulations, when ventilation was severely restricted, researchers found that oxygen levels could drop by up to 9%, which is around the point where a person may lose consciousness.
This may sound like a major deterrent, and yet hundreds of ancient Paleolithic cave paintings from 14,000 to 40,000 years ago are located at very similar depths. In fact, some rock art has been found as far from the mouth of a cave as an artist could get.
In the French cave of Rouffignac, for example, the oldest images were painted on the walls of extremely narrow passages, 730 meters (about 2,400 feet) from the only entrance.
Rouffignac cave map with red dots representing rock art. (Dachary, Plassard and Valladas, 2016)
Therefore, it seems possible that some ancient people crawled deep into the dark caves of Europe to intentionally enter a changed state of consciousness. The effects of sensory deprivation, combined with a lack of oxygen, could have been the trigger for the surreal nature of their rock art.
“Images imagined in such a hallucinatory state seem to float on the surfaces of the cave (walls, floors and ceilings) as if they were a membrane that connects the upper and lower worlds,” the authors explain. Kedar now hopes to test oxygen levels in real caves to compare them to simulations.
While psychoactive plants are certainly available in Europe, evidence of their use appears much later in archaeological records than these cave paintings.
Therefore, hypoxia could have been an easier and more natural way for the first people to knowingly change their mood, making a person feel more connected to the world around them and more expressive in their work.
Lascaux Caves in France – home to some of the most famous paintings of the Upper Paleolithic – have even been found to leach natural gas, which could have induced a hallucinatory state similar to ancient humans.
“The cave environment was designed both as a liminal space and as an ontological arena, allowing early humans to maintain contact with the cosmos,” the authors propose.
“It was not the decoration that made the caves significant; rather, the significance of the chosen caves was the reason for their decoration.”
The study was published in Journal of Archeology, Consciousness and Culture.