Cognitive Archeology and the Attentional System: An Evolutionary Mismatch for the Genus Homo

Abstract

Brain evolution is a key topic in evolutionary anthropology. Unfortunately, in this sense the fossil record can usually support limited anatomical and behavioral inferences. Nonetheless, information from fossil species is, in any case, particularly valuable, because it represents the only direct proof of cerebral and behavioral changes throughout the human phylogeny. Recently, archeology and psychology have been integrated in the field of cognitive archeology, which aims to interpret current cognitive models according to the evidence we have on extinct human species. In this article, such evidence is reviewed in order to consider whether and to what extent the archeological record can supply information regarding changes of the attentional system in different taxa of the human genus. In particular, behavioral correlates associated with the fronto-parietal system and working memory are employed to consider recent changes in our species, Homo sapiens, and a mismatch between attentional and visuospatial ability is hypothesized. These two functional systems support present-moment awareness and mind-wandering, respectively, and their evolutionary unbalance can explain a structural sensitivity to psychological distress in our species.

Keywords: anxiety; attention; cognitive evolution; human evolution; human genus; parietal cortex; stress.

Figure 1

Approximate chronological extension of the human species with consistent paleontological and archeological record (Ma: million years; ka: thousands years). The digital replica shows the skull and endocast of KNM-ER 1813, a specimen assigned to the controversial species H. habilis. Redrawn after Bruner and Beaudet (2023).

Figure 2

Oldowan choppers, Acheulean handaxes, Mousterian flakes and Epipaleolithic point (not to scale). These tools display a decrease in size and an increase in geometrical and perceptual complexity. In general, however, more complex tools do not substitute the preceding technology, but are added to the general toolkit. Therefore, in later technological stages, there is a general overlap between more archaic and more derived tools. Redrawn after (Bruner et al. 2018c).

Figure 3

Choppers (a; above) and handaxes (a; below) trigger different visual exploration patterns. According to eye-tracking analysis, naïve subjects tend to distribute the fixations differently in the two tool types, both in terms of cortex vs. knapped surface (b—left drawing) and tip–center–bottom regions (b—right drawing). In any case, regions with high visual saliency (c; in red) do not capture visual attention, which is instead driven axially (d; red). Redrawn after Silva-Gago and Bruner (2023).

Figure 4

The Default Mode Network mainly deals with off-line egocentric narratives based on mental imaging and internal speech, while an important part of the attentional network concerns on-line perception and present moment awareness. The parietal lobes have a key role in both processes, and a proper cognitive efficiency depends on an accurate balance between these two systems. Meditation practice improves the ability to recognize mind-wandering and return to a present-moment attentional state.

Figure 5

Self-narrative is based on the capacity to extend past and future projections through mental imaging, speech and memories (a). An excess of ruminations may generate an over-representation of past and future projections, disconnection from the present moment and disproportionate mind-wandering (b). Meditation is a form of cognitive training aimed at focusing on the experience of the present moment, through proper control of the attentional resources (c). We might speculate that limitations in visual imaging and language (as hypothesized for extinct human species) could be associated with shorter and simpler self-narrative, which reduces mind-wandering but, at the same time, hampers a sustained and intentional capacity to support attentional awareness (d). These different conditions are likely to influence most aspects of the psychological, ecological, technological and social life of a person/species.