Scientists from RIKEN Brain Science Institute in Wako, Japan and the Institute of Neurology at University College London have discovered that the brains of macaque monkeys undergo significant development when they are taught how to use tools. This finding may imply that our advanced human brains got as big and powerful as they did thanks to using tools, rather than the other way around.
From RIKEN Research:
The researchers used a technique called voxel-based morphometry (VBM) to classify areas of brain tissue in their MRI images as grey matter, white matter, or cerebro-spinal fluid, and to compare the volume of each tissue at different stages of learning.
The analysis showed that the MRI signal from some areas of gray matter increased, suggesting their volume in the monkey’s brains increased as the monkeys got better at using the tool. The growth was mainly in areas around the superior temporal sulcus (STS), intraparietal sulcus (IPS), and the secondary somatosensory area (SII) which all belong to a network previously associated with tool use. The researchers also noticed an increase in signals, suggesting volume expansion, from white matter in the cerebellum, which is well known as having a role in motor control.
The study is important because it is the first to detect statistically significant brain structure changes in individual animals, compared to human studies that pooled data from several people.
Press release: Brain change …
Abstract in Proceedings of The National Academy of Sciences: Gray and white matter changes associated with tool-use learning in macaque monkeys
Images: Top: MRI images of the brain showing the areas around the intraperietal sulcus (IPS), superior temporal sulcus (STS) and the secondary somatosensory area (SII) in which gray matter increased as monkeys learned to use a rake tool to retrieve food (CS, central sulcus; IPS, intraprietal sulcus; LS, lateral sulcus). Side: romana klee