Lower and Middle Palaeolithic stone toolmaking and language: a preliminary experimental archaeological and psycholinguistic study (original) (raw)

Did early Homo have language? Neurocognition behind stone toolmaking

9th NeuRi Student Congress of Neuroscience. Abstract Book, 2019

Recently, considerable interest for language evolution has arisen. Many researchers believe that language evolved via exaptation of domain-general cognitive systems such as long-term memory, visuospatial processing and executive functioning. Therefore, many studies on language evolution have focused on determining when specific cognitive functions, which might have supported language, developed. One approach in this area has been to establish the neurocognitive and neural correlates of specific behaviours during the Palaeolithic period (from ~3.3 mya to ~10 kya). The focus has been on stone-toolmaking-related behaviours because of the higher preservation of stone in the archaeological record compared to other materials. The earliest stone industry is the pre-Homo Lomekwian. It has been hypothesized based on experimental replication of the knapping process that the Lomekwian findings are suggestive of lesser functional lateralization of the motoric and prefrontal cortex compared to modern humans. The next stone industry – the Oldowan –, typically associated with Homo habilis, has been linked to more complex subsistence strategies and social behaviours. Neuroimaging studies have shown that Oldowan toolmaking predominantly involves frontoparietal sensorimotor areas and the cerebellum, which is why this industry has been described as cognitively relatively „ape-like“. The following industry, the Acheulean, taxonomically linked to Homo erectus and chronologically coinciding with significant brain enlargements in our genus, is believed to be more demanding in hierarchical and sequential action processing compared to earlier technologies. Additionally, neuroimaging studies have shown higher activation of the right Broca's area and temporal cortici during Acheulean compared to Oldowan toolmaking. Recently, a study by our lab comparing sidescraper manufacture, associated with Homo heidelbergensis and Neanderthals, and Oldowan toolmaking has found higher involvement of visuospatial and executive functions in the former task. While it is hard to generalize based on this data, we will suggest some implications for the existence of language in early Homo.

Cognitive Demands of Lower Paleolithic Toolmaking

PloS one, 2015

Stone tools provide some of the most abundant, continuous, and high resolution evidence of behavioral change over human evolution, but their implications for cognitive evolution have remained unclear. We investigated the neurophysiological demands of stone toolmaking by training modern subjects in known Paleolithic methods ("Oldowan", "Acheulean") and collecting structural and functional brain imaging data as they made technical judgments (outcome prediction, strategic appropriateness) about planned actions on partially completed tools. Results show that this task affected neural activity and functional connectivity in dorsal prefrontal cortex, that effect magnitude correlated with the frequency of correct strategic judgments, and that the frequency of correct strategic judgments was predictive of success in Acheulean, but not Oldowan, toolmaking. This corroborates hypothesized cognitive control demands of Acheulean toolmaking, specifically including information ...

Human brain activity during stone tool production : tracing the evolution of cognition and language (2016)

2016

Some of the biggest questions in human evolution are why we have such large brains and how our ancestors acquired language and exceptional intelligence. Our extreme reliance on technology has set us humans and our ancestors apart from other primates for more than three million years. It is widely thought that tools from the distant past may hold the clues to answering these questions because they represent all that is left of ancient minds at work. This study addresses these questions by using brain imaging technology to determine which areas of the brain of modern-day humans become most active as they make two types of tools from the past, one from as early as 2.6 million years ago (Ma) known as the Oldowan industry, and the other from 1.75 Ma known as the early Acheulian industry. Because it remains unclear whether early humans possessed language this far back in the past, an instructor taught half of the participants in this study to make stone tools with language, while the other half learned by nonverbal imitation. The analysis of the resulting brain imaging data revealed that Acheulian toolmaking requires higher-order conceptualization than Oldowan toolmaking. Selection for individuals who could store and manipulate more information and therefore make the most productive Acheulian tools may have been the prime reason for the evolution of large brain size in humans. The complex cognition that evolved as a result of such technology likely provided the framework on which language could build.

Cognitive performance and specific aspects of language processing are associated with Oldowan-like chert flaking and retouch

2021

Experimental data suggesting a co-evolutionary relationship between Palaeolithic stone toolmaking, and cognition and language remain limited to indirect findings of neurophysiological studies. Furthermore, retouch and quartz flaking remain uninvestigated. We recruited thirteen subjects and taught them to produce quartz choppers and chert sidescrapers in either a verbal or gestural condition. Two raters rated on a 5-point scale the subjects’ performances on specific steps of the two stone toolmaking tasks. Subjects also performed on a neuropsychological battery encompassing visuospatial, executive functioning, and linguistic tasks. Given the small sample size, the results should be regarded as exploratory and preliminary. There was only limited evidence that verbal compared to gestural teaching facilitated acquisition. Quartz chopper manufacture was not associated with cognitive performance. Conversely, chert flaking and retouch were moderately and strongly associated with visuospati...

Manual Praxis in Stone Tool Manufacture: Implications for Language Evolution

Alternative functions of the left-hemisphere dominant Broca’s region have induced hypotheses regarding the evolutionary parallels between manual praxis and language in humans. Many recent studies on Broca’s area reveal several assumptions about the cognitive mechanisms that underlie both functions, including: 1) an accurate, finely controlled body schema, 2) increasing syntactical abilities, particularly for goal-oriented actions, and 3) bilaterality and fronto-parietal connectivity. Although these characteristics are supported by experimental paradigms, many researchers have failed to acknowledge a major line of evidence for the evolutionary development of these traits: stone tools. The neuroscience of stone tool manufacture is a viable proxy for understanding evolutionary aspects of manual praxis and language, and may provide key information for evaluating competing hypotheses on the co-evolution of these cognitive domains in our species.

The functional brain networks that underlie Early Stone Age tool manufacture

Nature Human Behaviour, 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 work1,2—was only engaged during verbal training. Acheulian toolmaking, therefore, may have more evolutionary ties to playing Mozart than quoting Shakespeare.

Teaching to make stone tools: new experimental evidence supporting a technological hypothesis for the origins of language OPEN

The relationship between lithic technology, learning and language is a topic of growing interest in human evolution studies, and has therefore been the subject of numerous scientific papers in recent years. To evaluate the role of language in the social transmission of lithic technology, we designed and developed an experimental protocol through which we compared the acquisition of knapping skills in thirty non-experts in the early stages of learning, by means of three mechanisms of social transmission: imitation-emulation, gestural communication, and verbal communication. All the apprentice knappers carried out the experimental task with blanks that were equal in shape and size, and were requested to replicate what the expert knapper was doing: the alternating method, a sufficiently simple, but systematic technique for detaching flakes from a core. We analysed each participant's actions, including those of the master knapper, the final products (flakes and cores), and the knapping sequences, by analysing the refits. Our results show that the apprentices improved their knapping skills in teaching conditions-both gestural and verbal communication-, and specially through the latter. In conclusion, our study supports the hypothesis of co-evolution between lithic technology and social learning, which could have favoured the emergence of verbal language. Complex lithic technological capacity and language compete with each other to be the insignia of human intelligence , due to their cognitive implications. While stone tools have remained more or less unchanged in the archaeological record and act as a window into the behaviour of pre-modern hominins 1 , language does not fossilise. This means indirect approaches are necessary to approximate this capacity in extinct hominins 2–4. This hinders the study of the relationship between lithic technology and language in evolutionary terms, and this currently remains controversial 5,6. Several experimental studies in cognitive neuroscience have focused on Broca's area in the frontal lobe which is involved in language production 7–10 , and manual praxis 11–13 , such as those involved in tool production 10,14–16. Some experimental works focusing on Broca's area have looked at the overlap between language and the production of Lower Palaeolithic tools 17 , both for Oldowan 18,19 and Acheulian industries 20,21 with opposite results. Furthermore, Stout and colleagues have also explored the brain processes involved in the acquisition of knowledge related to the knapping methods associated with these technologies 22. In addition, language and the production of Acheulian tools have been shown to cause the same lateralization of blood flow in the brain 23. This body of study comprises evidence supporting the technological hypothesis of the origin of language, and particularly the technological pedagogy hypothesis 6 , which contends that intentional pedagogical demonstration may have spurred the evolution of the verbal communication 24. In fact, some authors have proposed that social learning and pedagogy would have been key factors in the evolution of hominin brains 25–27. Furthermore, some ethnographic studies have reinforced the relationship between lithic technology and language , emphasising the social character of knapping in current human communities 28–33. In these groups, verbal