The functional brain networks that underlie Early Stone Age tool manufacture

By using highly advanced brain imaging technology to observe modern humans crafting ancient tools, an Indiana University neuroarchaeologist has found evidence that human-like ways of thinking may have emerged as early as 1.8 million years ago.

The results, reported in the journal Nature Human Behavior, place the appearance of human-like cognition at the emergence of Homo erectus, an early apelike species of human first found in Africa whose evolution predates Neanderthals by nearly 600,000 years.1

The functional brain networks that underlie Early Stone Age tool manufacture

Shelby S. Putt, Sobanawartiny Wijeakumar, Robert G. Franciscus & John P. Spencer

Nature Human Behaviour 1, Article number: 0102 (2017)

After 800,000 years of making simple Oldowan tools, early humans began manufacturing Acheulian handaxes around 1.75 million years ago. This advance is hypothesized to reflect an evolutionary change in hominin cognition and language abilities. We used a neuroarchaeology approach to investigate this hypothesis, recording brain activity using functional near-infrared spectroscopy as modern human participants learned to make Oldowan and Acheulian stone tools in either a verbal or nonverbal training context. Here we show that Acheulian tool production requires the integration of visual, auditory and sensorimotor information in the middle and superior temporal cortex, the guidance of visual working memory representations in the ventral precentral gyrus, and higher-order action planning via the supplementary motor area, activating a brain network that is also involved in modern piano playing. The right analogue to Broca’s area—which has linked tool manufacture and language in prior work12—was only engaged during verbal training. Acheulian toolmaking, therefore, may have more evolutionary ties to playing Mozart than quoting Shakespeare.

  • 1. Stout, D., Toth, N., Schick, K. D. & Chaminade, T. Neural correlates of Early Stone Age tool-making: technology, language and cognition in human evolution. Phil. Trans. R. Soc. B 363, 1939–1949 (2008).
  • 2. Stout, D. & Chaminade, T. Stone tools, language and the brain in human evolution. Phil. Trans. R. Soc. B 367, 75–87 (2012).