Somatotopic Maps

by Dr Marc Ellis

The relationship between our sensory and motor systems is a captivating subject that holds great importance for bodyworkers. Pioneers like Luigi Galvani and Charles Sherrington have provided groundbreaking discoveries that have shed light on the intricate interplay between nerves, muscles, and electric impulses.

Galvani’s experiments revealed that applying electricity to nerves could induce muscle contractions. Sherrington’s work in the early 20th century further expanded our understanding by highlighting reflex arcs between sensory and motor neurons. These foundational studies have paved the way for our current knowledge of how our nervous system functions.

In modern times, the works of Wilder Penfield have revealed another aspect of this complex relationship. The discovery of somatotopic maps in the brain, particularly in the primary sensory strip of the parietal lobe, has revolutionized our understanding of how sensory information is processed and relayed to motor systems. These maps, formed by cortical columns, play a crucial role in processing specific types of sensory information and integrating it with neighboring columns to interpret and interact with our environment.

The brain processes sensory information through parallel pathways known as the “what” and “where” pathways.  The “what” pathway is associated with object recognition and the “where” pathway is associated with processing spatial relationships. This information feeds forward to motor regions, allowing the brain to create a motor plan and execute precise motor control of the musculoskeletal system.  The motor systems will also modulate the activity of the relay neurons in the thalamus.  This sharpens the perception of relevant stimuli while filtering out unnecessary or distracting information.  The brain actually alters how its own sensory information is processed and perceived.  This helps people to have accurate experiences of their world.

 For example, if an experienced body worker is treating someone’s thoraco-lumbar fascia they can interpret what the tension means in relation to the client’s paraspinals.  As they create a motor command to palpate the rest of the back, they will alter the activity of sensory systems to improve the accuracy and understanding of their palpation.

The fascial system, intertwined with sensory neurons, plays a key role in maintaining overall health. Disruptions in the fascial matrix, such as the formation of scar tissue, can have a profound impact on nerve function, leading to increased pain perception and distortions in the somatotopic map.

Distortions in the somatotopic map can result in faulty movement patterns that leave individuals vulnerable to chronic soft tissue injuries. Repetitive injuries can further exacerbate these distortions, impacting both motor and cognitive functions and potentially leading to long-term musculoskeletal issues.

It is crucial to recognize the interconnectedness of the fascial system and sensory neurons in maintaining optimal health and preventing musculoskeletal issues. By understanding these complex interactions between sensory, motor, and cognitive systems, we can work towards restoring balance and promoting overall wellness. These intricate connections within our bodies shape our perception of the world around us, offering a deeper insight into our physical and emotional experiences.

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This Blog was Authored by Dr. Marc Ellis with the assistance of ChatGPt.

Dr. Ellis is the Clinic Director at Georgia Chiropractic Neurology Center.  This center attends patients from around the world who suffer from Concussions, Vertigo, Dysautonomia and various Pain Syndromes.  He is also the founder of his own technique called MyoSynaptics.  This technique integrates brain rehabilitation with myofascial treatments.  You can email him directly at HealthyBrainNow@gmail.com

References Material for this article came from

1. “The Principles of Neural Science” by Eric Kandel.

2. Hawkins, Jeff, et al. “A theory of how columns in the neocortex enable learning the structure of the world.” Frontiers in Neural Circuits, vol. 11, 25 Oct. 2017, https://doi.org/10.3389/fncir.2017.00081.

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A fuller version of this blog appears in the Members’ Area as an introduction to his Members’ Webinar on the topic of: Scar Tissue and Somatotopic Maps: Exploring the Impact on Pain and Motor Systems, which is also held in the Members’ Area. For details of our membership click here.