Portable pit picture and engravings may have been the original move exposure , see back to palaeolithic times . Archaeologists believe they were positioned around cave hearths so the figure present would seem to follow awake in the tilt visible light from the fires .

Human neurology is peculiarly attuned to interpreting shifting light source and shadow as movement,”Dr Andy Needhamof the University of York and conscientious objector - authors write inPLOS ONE . Ourpareidolia , the seeing of faces in non - human forms , goes into overdrive in such conditions .

While this phenomenon presumptively evolved to avoid our ancestors being eat on by night - hunt predator , some of those ancestor look to have put the capacity to use to make their prowess more powerful . After all , when the secure matter to do at Nox was to stay in the cave , no one wanted younger members of the federation of tribes catch bored . Art that perpetually changed in the shifting firelight may have been the paleolithic equivalent of a Playstation or a movie .

The artwork Needham is discuss is not thefabulous paintingsof the cave walls we connect with Paleolithic prowess . Instead these are what are live as plaquettes , stones modest enough to be portable and monotonic enough for easily seeable engravings . Although they have been found across Europe , these plaquettes are most common from Portugal to Germany and nearby islands . They depict animals , humans and abstract symbolisation , with occasional limning of what are thought to be rivers in style match what is get laid asMagdalenian .

Plaquettes were in all likelihood used in many ways , specially using their thermal properties . Often , however , archaeologists have not been able-bodied to give their purpose . Needham and Colorado - source conducted a detailed study of 54 plaquettes collected in the 19th century from Montastruc rock shelter , Southern France and mostly made of limestone .

Most of the plaquettes are engraved with image of bison , ibex , horses and cervid . A few have doll , parallel note or undetermined subjects . Often the lines are adjust to follow raw features of the rock . The large have faces rough the size of an A4 sheet of theme , but 3 centimeter ( 1.2 inches ) thick . Most are less than half that size of it .

Crucially for this work , all the limestones show evidence of heating plant after they were engraved , with cracking and thermic fractures seeable , as well as color changes specific to limestone heat to certain temperatures .

“ These plaquettes would have been site in nigh proximity to hearth structures in low luminousness levels , perhaps as a means of accentuate the human relationship between etch build and natural features in the rock , with the dynamic light cast from the fireplace bring the depicting to light , ” the authors reason .

That does n’t mean this was the only purpose for their placement close to fires . Limestone could also have service a part by radiating warmth in effect through the site and storing it for after the flack burned down , which the author note would have been crucial during a time of caustic cold .

Larger plaquettes could also have served as preparation stone . However , if these were their only purposes , the engraving would have been unnecessary . When the researcher order reproduction stones around open firing they plant the light enhance the relationship between the natural shape and the engravings and the move flaming made the sculpture appear dynamic . Some of the engraving , such as those present herds of horse and ibex , seem to have been specifically design to entrance this effect .

In compounding with the recent hypothesis that sure cave house painting were placed in fix where O want wouldinduce hallucinations , we may only have scratched the surface of the inventiveness of cave fine art .

Worked antlers find at Montastruc have been dated to around 14,000 class ago , towards the end of the last Ice Age , but whether the plaquettes are from the same metre is unsettled .