Human ability to create and utilize tools: an examination of how the brain develops these capabilities
In a groundbreaking study, a team of international researchers, led by Ella Striem-Amit from Georgetown University, have made significant strides in understanding the hierarchical organization of the motor system. The research, which was supported by the Edwin H. Richard and Elisabeth Richard von Matsch Distinguished Professorship in Neurological Diseases and a Shanghai Youth Science and Technology Innovation Plan award, also involved neuroscientists such as Jack L. Gallant and his colleagues from Georgetown University.
The study, published in the journal Nature, focused on action-type mapping in the motor system. To delve deeper into this topic, the researchers conducted experiments involving participants performing tool-use actions with their hands or feet. The primary aim was to examine if there is a body-part-independent action-type organization in sensorimotor areas.
The findings of the study support the use of a readout of a more abstract code for hierarchical brain-computer interfaces. Contrary to previous beliefs, the results suggest that the hierarchical organization of the motor system is not dependent on a long evolutionary history of an action. Instead, higher-level motor areas within the tool-use network represent abstract, action-type information independent of the body part.
To test this theory, the study included individuals born without hands. This was to determine whether hand sensorimotor experience is necessary for the development of this action-type organization. The results showed that even in the absence of hand sensorimotor experience, the functional reorganization in congenital handlessness follows the hierarchical organization of the intact cortex, revealing the limitations of brain plasticity.
Intriguingly, the primary sensorimotor cortices encoded concrete, body-part specific information in both groups. This indicates that even in the context of a more abstract code, the brain still retains a certain level of specificity when it comes to body part information.
The authors of the study report having no personal financial interests related to the study, ensuring the findings' objectivity. This research not only provides valuable insights into the motor system's organization but also paves the way for advancements in brain-computer interfaces.
