Early Tool-Making and the Evolution of Human Memory Systems in the Brain

Abstract

Outlines about ancient Paleolithic artifacts and early Homo (2-1 Ma) skeletons precede considerations about cognitive versatility and developmental limitations of evolving brains. The adaptive behavior included technical skilfulness, reflected by artifact diversity, and manual dexterity requiring backward “haptic” touch memory, needed for habitual automatic, accurate handiwork, and forward “prospective” memory about foreseeably usable tools. Observational learning transmits skill insecurely, endangering persistence of evolutionary advantages. Their genetic or epigenetic underpinning enabled cerebral enlargement, affecting regions for different kinds of memory, imitation, language, and tool-use. Fundamental matters include imitative behavior and prefrontal and parietal mirror-neuron circuits, inferior parietal lobule tool-using specificity, long-term procedural memory and temporal lobe hippocampal-parahippocampal cortex, and working memory and neuronal haptic responses in prefrontal and parietal cortex. All underpin human capacities, whereby haptic working memory and propensity for habitual procedural memory evolved alongside explicit and implicit mental perspectives blending past and present behavioral memories into alternative behavioral concepts underlying Paleolithic diversity.