Lithic Industry: Eye-Tracking Debut

Lithic Industry

First application of the eye-tracking methodology to studying lithic industry.

The journal Archaeological and Anthropological Sciences published a study from The Paleoneurology Group at the Centro Nacional de Investigación Sobre la Evolución Humana (CENIEH)

 led by Emiliano Bruner. This study, analyzes the patterns of visual exploration during handling of Lower Paleolithic tools, being the first application of the eye-tracking methodology to real stone tools.

Eye-Tracking Study Reveals Visual Attention in Tool Interaction

The study was in collaboration with the University of Lincoln (United Kingdom), Universidad Isabel I in Burgos, and the Centro de Arqueología Experimental de Atapuerca (CAREX). Its goal was to investigate the body-tool interaction from a cognitive perspective to see which sections of tools attract the most attention.

Eye-tracking is one of the methods for investigating visual perception, which consists of the detection of the movements of the pupil through an infrared system. The study employs this technology during visual exploration and handling of an array of tools, consisting of worked pebbles and handaxes.

The researcher María Silva Gago, lead author of this work, explains that this allows them to quantify attention time and analyze which parts of the tools the gaze focuses on during the exploration process. 

Visual Behavior and Affordances of Lower Paleolithic Tools

The results show that the region most gazed upon is the central area of the tool, followed by the top and the base. Simultaneously, the natural surface attracts less attention than the worked parts. Silva adds that the gaze is focused mainly on the functional areas.

Differences in the visual exploration patterns were observed when comparing the two types of tools used. Still, this exploration strategy remains the same whether these tools are simply observed or are both observed and handled.

Vision is our primary source of information and plays an essential role in perceiving the affordances of objects: This is a principle widely used in psychology, to describe the properties or features which inform us how or for what a particular object is used. “Distinguishing these affordances is an involuntary act we perform daily,” states Silva.

The results acquired in this study imply that visual behavior is directed by the perception of affordances, potentially since the brain-body-tool interaction, related to the culture of the Lower Paleolithic, first emerged.

More information: María Silva-Gago et al, Visual attention reveals affordances during Lower Palaeolithic stone tool exploration, Archaeological and Anthropological Sciences (2021). DOI: 10.1007/s12520-021-01413-1