University of Wollongong researchers have experimentally confirmed that changes in hammer strike angle significantly affect the fracture path and form of stone flakes produced by Neanderthals during the Middle Paleolithic.

Published in Archaeological and Anthropological Sciences, the findings contradict a widely cited fracture model that credited rock core geometry and stiffness with flaking patterns and predicted that hammer strike angle would have minimal effect on flake formation. Results suggest a greater degree of cognitive control by early human tool makers than previously recognized.

Middle Paleolithic stone tool technology is defined by deliberate core preparation to produce flakes of predetermined size and shape. First appearing in the archaeological record between 200,000 and 400,000 years ago, the Levallois method is a hallmark of Neanderthal tool making in this period.

Bollmann et al. track reactivated CA1 assemblies representing spatial memories during 16–20 h of sleep/rest. Assemblies initially reflect recently learned spatial memories but are gradually transformed into those seen during the memory recall session following rest. Whereas slow-wave sleep accelerates the assembly drift, REM epochs counteract it.

As they age, some people find it harder to understand speech in noisy environments. Now, University at Buffalo researchers have identified the area in the brain, called the insula, that shows significant changes in people who struggle with speech in noise.

The findings, published in the journal Brain and Language, contribute to the growing link between hearing loss and cognitive impairment leading to dementia. Previous research has separately established connections between hearing difficulties and dementia, as well as insula abnormalities and cognitive decline.

The insulae are two complicated structures that interact with the brain’s frontal lobe, which is responsible for higher-level cognitive function. The insulae integrate sensory, emotional and cognitive information.