Great minds throughout human history have struggled to understand the true link between mind and body. But it appears that the brain’s fundamental anatomy holds the key.
Researchers have found connections between the portions of the motor cortex, a part of the brain that controls movement, and a network that manages thinking, mental arousal, planning, pain, internal organ regulation, as well as physiological processes like heart rate and blood pressure.
They discovered a previously unexplored system within the motor cortex that appears as multiple nodes situated between regions of the brain already known to be in charge of movement of particular motion parts, such as the hands, feet, and face, and that become active when numerous are performed simultaneously.
The somato-cognitive action network, also known as SCAN, was named by the researchers who also noted its link to brain areas associated with goal-setting and action planning.
The areas of the brain tied to internal organs like the stomach and adrenal glands in trials involving monkeys were also discovered to correspond with this same network, enabling these organs to alter their activity levels in anticipation of carrying out a particular action.
They suggested that this may explain how thinking about a challenging task can cause physical reactions like perspiration or an elevated heart rate.
The cerebral cortex, the top layer of the brain, contains the motor cortex.
Evan Gordon, a radiology professor and the lead author of the study published in Nature, explains that “Basically, we’ve now shown that the human motor system isn’t unitary. Instead, we believe that there are separate systems that control movement. One is for isolated movement of the hands, feet and face. This system is important, for instance, for writing or speaking, movements that need to involve only one body part. A second system, the so-called SCAN, is more important for whole body integrated movements, and is more connected to high level planning regions of your brain.”
Nico Dosenbach, the study’s senior author and a neurology professor, goes on to share that “Modern neuroscience doesn’t include any kind of mind-body dualism. It is not compatible with being a serious neuroscientist nowadays. I am not a philosopher, but one succinct statement I like is saying, ‘The mind’s what the brain does.’ The sum of the bio computational functions of the human brain makes up ‘the mind. Since the SCAN, this system, seems to integrate abstract plans thoughts motivations with actual movements and physiology, it provides an additional neuroanatomical explanation for the reason why ‘the body’ and ‘the mind’ are not separate or separable.”
The goal of this study was to test an impactful map of the brain regions dictating movement created by neurosurgeon Wilder Penfield 90 years ago using cutting-edge brain imaging techniques.
Their conclusions demonstrated that Penfield’s map, limited by the tools of his time, required revision.
Precision imaging was used to identify the SCAN in 7 adults in order to examine the organizational features of the brain.
The SCAN was later confirmed in larger datasets that, once merged, covered thousands of adults.
Further imaging revealed the SCAN circuit in two children, aged 9 and 11 months, but it had not yet developed in a newborn.
These findings were confirmed in larger datasets containing thousands of 9-year-olds as well as hundreds of newborns.
Gordon says that “Actually, the purpose of the brain is highly debated. Some neuroscientists believe the brain is an organ primarily intended to perceive and interpret the world all around us. Others think of it as an organ made to produce the best ‘outputs’ – usually a more physical action – to optimize survivability and the evolutionary fitness for any sort of situation. Probably both are correct. The SCAN does fit most cleanly with the latter interpretation, however: it integrates goals and planning with whole body actions.”
