Emiliano BrunerAbstract: Brain evolution is a key topic in evolutionary anthropology. Unfortunately, in this sense thefossil 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.
In contrast, the parietal cortex (a region that is crucially involved in the attentional network) has displayed evident morphological variations through the human phylogeny. The parietal cortex is particularly expanded, diversied and connected in primates, and particularly in H. sapiens (Goldring and Krubitzer 2017). The parietal lobe is a major cerebral hub in terms of functional and structural networks (Hagmann et al. 2008), and it is characterized by an intense metabolic load (Vaishnavi et al. 2010). In general, if we compare the morphological variation among primates and within the human genus, the parietal lobes are wider in Neanderthals, and much more expanded in modern humans (Bruner 2018). Part of such shape variation might be due to geometrical and structural changes in the cranial architecture (Zollikofer et al. 2022). However, when cerebral (lobe) anatomical references are used instead of cranial (bone) metrics, there is also evidence of a real expansion of the external cort
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2020). In H. sapiens and H. neanderthalensis, the inferior parietal lobule and the intraparietal sulcus have likely been involved in these macroscopic changes. It is worth noting that, among the many functions these areas are involved in (including eyehand coordination), they also look crucial for technical reasoning (Federico et al. 2022). However, in the case of modern humans, we can additionally speculate a further contribution of the precuneus, which is also much expanded in H. sapiens when compared with apes (Bruner et al. 2017a;
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9 of 18 J. Intell. 2023, 11, 183
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Willbrand et al. 2023). The precuneus, in terms of architecture, includes the superior parietal lobule, and it is generally separated into an anterior, a middle, and a posterior area (Scheperjans et al. 2008). The anterior region is more involved in somatic integration, the posterior one in visual integration, and the middle part is a bridge between body perception and vision (Cavanna and Trimble 2006; Margulies et al. 2009; Zhang and Li 2012). Such parcellation is in agreement with cortical gradients (Huntenburg et al. 2017)in this case a pretty linear gradientbetween somatic and visual perceptual regions. In this sense, the precuneus can be interpreted as a peculiar association region, because of its intimate connection with and dependence on sensorial inputs (in contrast with the noncanonical organization of many association areas; Buckner and Krienen 2013). Interestingly, general spatial models suggest that the diversity and variation of the precuneus among adult modern humans mi
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