25th November 2021

From Fossils To Mind Workshop 2021: Mathilde Salagnon

Neural Correlates of Perceiving and Interpreting Engraved Prehistoric Patterns as Human Productions 

Mathilde Salagnon

Affiliation

1 Univ. Bordeaux, GIN, IMN UMR 5293, Bordeaux, France
2 CNRS, GIN, IMN UMR 5293, Bordeaux, France
3 CEA, GIN, IMN UMR 5293, Bordeaux, France

Abstract

It has been proposed that engraved abstract patterns dating from the Middle and Lower Palaeolithic could have served as a communication medium. Identifying the  brain regions involved in the visual processing of these marks can provide insights  into the function they had in the past. In this study, brain activity was measured, using  functional magnetic resonance imaging, during the perception of engraved patterns  and natural patterns mimicking human-made engravings. Participants had to  categorise Palaeolithic marks as being intentionally made by humans or due to natural  processes (e.g. erosion, fossilisation). To simulate the putative familiarity of our  ancestors with marks, expert archaeologists and control participants were compared,  allowing to characterise the effect of previous knowledge on both behaviour and brain  activity in marks perception.

Besides a set of regions common to both groups involved  in visual analysis and decision-making, Experts exhibited greater activity in the inferior  part of the lateral occipital cortex, ventral occipitotemporal cortex, and medial thalamic  regions. Although they were in an unexplored area of expertise, these results were consistent with those reported in the visual expertise studies and confirm the importance of the integrative visual areas in the perception of engravings. Attributing a natural rather than a human origin to the marks elicited greater activity in the salience network in both groups, reflecting the uncertainty and perceptual ambiguity of natural marks and uncertainty in decision-making for natural patterns.