Neurosciences unlock the secret of the first abstract engravings
An unprecedented collaboration between archaeologists from the Pacea laboratory* and researchers in cognitive neuroimaging from the GIN** investigated the nature of prehistoric engravings. The results of this study have been published in Royal Society Open Science.
Released on July 3rd , 2019, the study conducted by two research teams from Bordeaux reinforces the hypothesis that our ancestors attributed meaning to their abstract patterns, perhaps even symbolic. The aim of this multidisciplinary study was to determine whether these prehistoric tracings, the earliest being 540,000 years old, are the result of unpurposive behavior, the simple desire of imitating nature or endowed with meaning.
To this purpose, the researchers mapped the regions of the brain involved in the perception the engravings. Results show that these abstract tracings are processed by the same brain areas that recognize objects. They also activate a region of the left hemisphere that is well known in the processing of written language.
Neurosciences at the service of archaeology
From Paleolithic paintings to the invention of writing, the production and perception of symbolic representations has been a major aspect of the human cognitive activity. To this day, however, there is no consensus on the emergence of symbolic behaviours among our ancestors.
For some, there would have been a sudden cognitive revolution contemporaneous with the arrival of modern populations in Europe 42,000 years ago. For others, the discovery of personal ornament, pigments and abstract engravings at African sites older than 100,000 years would show that symbolic practices appeared earlier and would be the consequence of the origin of our species in this continent. For others, Neanderthals and other so-called archaic populations also had symbolic behaviors.
A small group of abstract engravings was discovered in African and Eurasian sites older than 40,000 years. To clarify the nature of these engravings, two archaeologists from the Pacea laboratory* and five researchers from the GIN** mapped the regions of the brain involved in the perception of the oldest Palaeolithic engravings.
Brain mapping of graphic expressions
Using functional brain imaging techniques, the researchers compared the brain areas that were activated when participants were shown the outlines of the oldest engravings with those that were activated when presented with other types of representations. The human visual system is organized hierarchically, with so-called primary areas that analyze the elements that make up an image (contrast, color, orientation) and secondary areas that make it possible to distinguish the different visual categories. Indeed, some brain areas are more specialized in landscape analysis, others in object or writing analysis.
The brain areas activated by the prehistorical engravings were compared to those activated by objects, words, landscapes, and ancient alphabet. Result: the perception of Palaeolithic engravings activates the same cerebral zones as objects, while it does not affect the activity of zones related to the perception of landscapes or an ancient alphabet. This confirms that the oldest abstract engravings have visual properties similar to those of objects to which meaning can be attributed. In addition, the engravings activate a brain area lateralized in the left hemisphere, known for its involvement in written language processing, which reinforces the idea that these engravings had the potential to serve as a means of communication for the first humans.
* Pacea – From Prehistory to Modern Times: Culture, Environment and Anthropology (CNRS/University of Bordeaux/French Ministry of Culture)
** GIN – Neurofunctional imaging group of the Neurodegenerative diseases institute (CNRS/CEA/Université de Bordeaux)
Mellet E, Salagnon M, Majkic ́A, Cremona S, Joliot M, Jobard G, Mazoyer B, Tzourio-Mazoyer N, d’Errico F. 2019 Neuroimaging supports the representational nature of the earliest human engravings. R. Soc.open sci.6: 90086.
Researcher in cognitive neuroimaging
Archaeologist at the Pacea laboratory