The role of experience during the exploration of lithic artefacts can be been investigated through multiple approaches. Knowledge can influence visual perception of the environment, whilst action “affordances” can be processed at the first sight of an object. In this study, we used eye tracking to analyse whether and to what extent archaeological knowledge can influence visuospatial attention whilst interacting with stone tools. Archaeologists were found to pay more visual attention to the middle region and the knapped surface. Differences between the visual exploration of choppers and handaxes were also found. Although the general pattern of distribution of the visual attention was similar to naïve subjects, participants with archaeological experience paid more attention to functionally relevant regions. Individuals with archaeological experience directed more attention to the upper region and the knapped surface of the tools, whilst naïve participants spent more time viewing the middle region. We conclude that although both groups could direct their attention to action relevant features in stone tools, functional affordances had a greater effect in subjects with previous experience. Affordances related to manipulation triggered lower attention and showed no differences between participants.

Humans are specialized in eye-hand coordination through a complex visuospatial system. When a tool is observed, the motor areas of the brain are activated and, when grasped, it is sensed as a part of the body. One approach to understanding the underlying mechanisms behind this process regards the analysis of visual attention. Vision influences the spatial interaction with tools and plays a crucial role in the perception of an object’s affordances. In this study, we employ eye-tracking technology to investigate whether Lower Palaeolithic stone tool morphology influences visual attention during visual exploration and manipulation. Our results suggest that the handaxe morphology has a moderate influence on the visual scanning of the tool. In contrast, visual exploration of the chopper is only influenced by the weight of the tool. The different visual behaviours exerted by these two technologies suggest divergences in the visuospatial process underlying the interaction with these tools.

Considering the biomechanical and cognitive aspects involved in tool manipulation, hand size emerges as a critical factor. Males, on average, exhibit greater grip strength attributed to larger hand dimensions. Beyond mere physical factors, cognitive components tied to visuospatial abilities also influence stone tool use. However, the intricate relationship between hand size, grip strength, and ergonomic patterns necessitates further exploration. Here, we study the ergonomic pattern of phalanx flexion during the manipulation of Lower Paleolithic stone tools (choppers and handaxes) to understand the nuanced interplay between hand dimensions and grasping behaviors in Lower Paleolithic stone tool use. The static hand posture during the comfortable grasping of each tool is measured using a motion capture hand glove. Flexions are measured at the metacarpophalangeal joint, the proximal interphalangeal joint and the distal interphalangeal joint of each finger. Our investigation into Lower Paleolithic stone tool manipulation reveals gender-based differences in phalanx flexion, with hand dimensions showing correlation only in pooled samples. However, these associations diminish when analyzing males and females separately. This study suggests a minimal link between hand size and grasping behavior within our sample, hinting at the influence of cognitive, behavioral, and motor factors. Exploring lifestyle and psychometric profiles could provide further insights. In the context of early human technology, our results prompt considerations on the evolution of the hand-tool interaction system, linking our tool-dependent culture to our phylogenetic history.