Journey to the Center of the Brain

Part 1: An Introduction

 In 1864, Jules Verne published his classic science fiction novel Journey to the Center of the Earth. The chronicle detailed the adventures of Professor Otto Lidenbrock, his nephew Axel, and their guide Hans, as they valiantly traveled into the earth’s interior. The professor had scientific theories about the earth’s core that coincided with his hopes to confirm or revise his assumptions. As a licensed clinical therapist, psychology student, and neurology nerd…I feel a little like Professor Lidenbrock when I think about the human brain. Human skulls hold an organ that out-computes any known supercomputer, and our understanding of this organ has radically increased in the last 30 years with the invention of fMRI scans. Scans let us see what parts of the brain light up when we think, feel, or act in certain ways. Because brain health impacts every human experience, I often educate my clients about what is happening in their brains during our sessions. It complements their understanding of cognitions, feelings, and behaviors so they can adjust their lifestyles as desired. Similarly, I want to share what I have learned about neurology here, in the upcoming blog posts, to guide readers on a magnificent journey!

In this series’ first post, I will detail parts of the brain and their functions as they relate to optimal health and well-being. This will give readers a foundation for which to absorb the second and third blog posts, which will describe what is happening in the brain during common situations that many people experience. For instance, post two will summarize neurological processes when humans get stressed. Post three will follow a similar layout, but instead of illustrating the optimal and worst-case scenarios for stress management, it will trail the brain activity associated with compulsivity and addiction. These are topics that I reference often in counseling because I have clinical specialties as a trauma-informed therapist and sex addiction recovery specialist. If these are issues that are impacting you, be on the lookout for parts two and three of the series, and do not hesitate to reach out to a counselor for guidance.

Typical Brain Development

One of my great desires is for this post to capture your attention versus read like an academic journal, so I am going to start with some intriguing (maybe even mind-blowing) facts about the brain. First, the brain begins growing during the mother’s third gestational week in pregnancy (1), and some experts believe the brain never stops growing, but only slows down between adolescence and age 30. To develop, the brain starts with our genes, which are encoded material in our DNA. When that is extracted, re-coded, and translated into proteins, the proteins interact with our environment. This process ends in a complete human brain, body, personality, and more1. Now, a young brain reaches 90 percent of its full volume (which will weigh about 3 pounds in adulthood) by the age of six (1). Interestingly, the brain is not considered a muscle, though I later outline how treating it like a muscle will benefit readers. Instead, the brain is mostly made up of fat (60 percent) with its remaining 40 percent made up of water, protein, carbohydrates, and salts (2). The human brain is composed of more than 100 billion neurons (1) – according to NASA, that is equal to the most common estimate of the number of stars in a Milky Way (3). Neurons make up the information processing highways that are responsible for our thoughts, sensations, feelings, and actions; each neuron can connect with up to 1,000 other neurons, making 60 trillion neural connection possibilities (1).

Here are the main conclusions from the paragraph above. First, the brain develops quickly and early in our lives as an interaction between our genes and environment, although it never stops growing due to what’s called neuroplasticity (4). Second, the brain is tremendously complex, even if only looking at it from the number of neurons and neural connections possible. But its complexity begins versus ends there. According to Dr. Dan Siegel (5), the brain is not the same thing as the mind; the mind encompasses the brain-body system. For readers wanting to connect this neurology to practical, every-day psychology – this is where things get interesting and helpful! Moore et al. (4) summarize the different bodily systems that we might consider when consider mind health: 

Our bodies develop and function in an integrated manner, with the brain intricately connected to other major bodily systems, including the immune, endocrinal, metabolic, cardiovascular, and muscular and skeletal systems. These systems shape and are shaped by each other. Learning is not purely cognitive or conscious. This integration of bodily systems means that what is ‘learned’ in the prenatal and first two to three years of life has potentially profound consequences throughout the life course. Many challenges faced by adults, such as mental health issues, obesity, heart disease, criminality, and poor literacy and numeracy, can be traced back to pathways that originated in early childhood.

Understanding Developmental Issues

When I share information like this, many people feel stuck. Fear not – your fate was not sealed when you reached the age of three! Although trauma can stall some brain development during/after the first few years of life, you can get your brain unstuck. This journey to a stronger mind begins by using your brain’s adaptivity (i.e., neuroplasticity) through self-awareness, cognitive reframing, experiential healing, skill training, and more. I often help my clients wrestle with questions like these: 1) how did what you went through in your first few years of life impact how you see the world? 2) How does your body react to adverse situations that might indicate a stuckness in certain brain areas? And 3) how can you utilize your mind’s neuroplasticity to manage your relationships, stressors, etc. in new ways? These three questions will guide the remainder of this blog series, though I will only scratch the surface of how this works. A fantastic book that is leading the way in this type of trauma-based mind recovery is by Dr. Bessel van der Kolk (6) called The Body Keeps the Score. However, most people struggle doing this recovery work on their own, which is why they engage therapists, psychologists, clinicians, mentors, and coaches in the journey.

Since this is still an introductory post, let me overview the major brain segments and how they impact an individual’s worldview. I will outline their most important functions as well as how they aid in psychological recovery. For a more in-depth overview of brain architecture, and excellent pictures to go with it, check out Brain Anatomy and How the Brain Works by Johns Hopkins Medicine (JHM). I have placed one of JHM’s (2) images below for reference during the remainder of the blog post:

How Hemispheres Help with Healing

The brain is made up of several major sections: the cerebrum, cerebellum, and brainstem – all a part of the central nervous system (CNS) (2). The cerebrum, or front of the brain, is responsible for movement, temperature regulation, speech, judgment, thinking, reasoning, problem-solving, emotions, and learning (2). Many psychological professionals informally call this the human brain; it offers us functions that differentiate us from animals. The cerebellum, or little brain, is a fist-sized section that fits underneath the cerebrum – its jobs are to coordinate voluntary muscle movement and maintain posture, balance, and equilibrium (2). The brainstem/spinal cord sends neural signals from the brain throughout the body through the polyvagal nerve, like a grand central station for brain-body communication.

Scientists recognize that the cerebrum and cerebellum have two hemispheres, the left and right (2). The left side of the brain is responsible for controlling functions of the right side of the body and vice versa. Additionally, the left side of the brain is primarily activated when using language or reasoning abilities. It activates for cues of emotional value more slowly than the right side of the brain (7). The right brain is alternately responsible for spatial, non-verbal, musical, relational, and emotional faculties (2); in the words of Marcus Warner and Dr. Jim Wilder (8), the right brain is the fast track because it works slightly quicker than the left. This is important; often when my clients try to reason or talk their way through emotionally or relationally oriented trauma, they cannot figure it out in a manner of speaking. This is because of the way the brain works. To emotionally mature through trauma and see our memories in new ways, practitioners (with specialized training like EMDR) help clients focus on processing through the emotional remnants of memories versus trying to explain them (9). This helps clients to activate under-functioning parts of the brain to encourage new development. Once that occurs, the hemispheres work together to integrate new perceptions of the memories into verbal, logical meaning; this is how the left brain supports the right during healing. 

Fight/Flight/Freeze in the Brain

The brain’s limbic system is a major factor in how we work through adversity in life. This system is composed of multiple segments of your brain, including (but not limited to) the amygdalae, hippocampi, hypothalamus, and pituitary gland. The limbic system is sometimes referred to as the emotional brain because it is the control center for our survival mechanisms like feeding, reproduction, caring for young, and our fight/flight/freeze responses (10), which all mammals have. Therefore, it can informally be called the mammalian brain. Let us outline in more detail below how it works. 

Amygdalae – Brain 911

The right and left amygdalae are the alert centers of the brain. They play the primary function of connecting our emotional content with our memories (10).  When something happens in life that packs an emotional punch, our amygdalae immediately go into action subconsciously without us thinking about it. Behind every experienced emotion is a felt need that starts in the amygdalae. For example: sadness might be described as an alert to someone who is experiencing a loss, so the associated need is to grieve that loss or see it in a new way. Similarly, anger signals to one’s brain that something feels unjust around him or her, so the individual must discern whether to fight the injustice, remove him/herself from it, or see it in a new way. Here is an amazing fact – only few parts of the brain are correlated with creating new adult neurons which are necessary for learning: the amygdalae and the hippocampi (10). That means that our ability to learn new habits (and shift old tendencies, in the case of trauma) is directly tied with how the memories are stored emotionally in our brains (8). 

Hippocampi – Memory Directors

The hippocampi, like the amygdalae, come as a pair and are primarily reserved as the “memory centers of our brains” (10). This is the part of the brain that forms and catalogs short-term memories into long-term storage. In 2015, Disney produced an entertaining and surprisingly accurate animated movie on neuroscience called Inside Out. In the film, the hippocampi would be the rollers on which the memory orbs flowed from the command center to the orb racks beyond the islands. The hippocampi also help associate memories with our sensory perceptions, like sight, smell, taste, sound, and touch. Fascinatingly, engaging these senses during trauma-recovery therapy is a significant part of the healing process (9). I also remind clients about how the olfactory nerve (governing the sense of smell in the brain) is directly connected to the limbic system, so anytime one smells something, it can remind him/her of a positive or negative past event.

Hypothalamus – Play Maker

Next, the amygdalae send alerts to the hypothalamus, which is effectively the quarterback of the limbic system. Though this is more formally a part of the cerebral cortex, it has significant interactions with the limbic system, so I include it here. The hypothalamus engages the brain-body system during emotional moments. It is involved in receiving messages from the amygdalae then initiating hormonal activity through our CNS. This part of the brain regulates things like blood pressure, sleep patterns, body temperature, hunger/thirst, homeostasis, and interacts with the amygdalae and hippocampi for memory and emotion (2, 11). The hypothalamus relays messages to the pituitary gland (a lot like a quarterback redirects the ball to running backs or receivers) so that it can begin producing hormones like cortisol and adrenaline. 

Pituitary Gland – Chief Executor

Lastly, the pituitary gland receives signals sent by the hypothalamus to govern the remaining bodily glands (i.e., the endocrine system); its purpose is to downshift (lessen) certain autonomic processes in the body and upshift (increase) others. The pituitary gland is the ignition for the endocrine system, which includes hormones released from the thyroid, adrenals, ovaries, testicles, and more (2). Anyone who has participated in a stressful activity can attest to the effects of the endocrine system. For instance, when we become aroused by stress, our ration, hunger/thirst, digestion, immunity, etc. upshift, while other processes like heart rate, blood pressure, muscle capabilities, etc. downshift. More to come on these shifts in blog post two and three during this series.

Conclusion

It may be hard to believe, but this blog post only touched the surface of the brain’s complexity when it comes to development and healing potential. The primary purpose for this post’s brain analysis was to prepare readers for the next two blog posts, during which I will reference the terms above often to help detail healing through distress and addiction. My hope is that this series will help readers better understand what is happening in their mind during difficult times. By journeying into the brain together, we can live and grow in new and wonderful ways!

References

1. Stiles, J., & Jernigan, T. L. (2010). The basics of brain development. Neuropsychology Review, 20(4), 327–348. https://doi.org/10.1007/s11065-010-9148-4
2. Johns Hopkins Medicine. (2022). Health – conditions and diseases: Brain anatomy and how the brain works [Blog post]. HopkinsMedicine.org. Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-of-the-brain
3. Mitchell, S., & Masetti, M. (n.d.). How many stars are in the milky way [Blog post]? ASD.GSFC.NASA.gov. Retrieved from https://asd.gsfc.nasa.gov/blueshift/index.php/2015/07/22/how-many-stars-in-the-milky-way/
4. Moore, T.G., Arefadib, N., Deery, A., Keyes, M. & West, S. (2017). The First Thousand Days: An Evidence Paper – Summary. Parkville, Victoria: Centre for Community Child Health, Murdoch Children’s Research Institute.
5. Siegel, D. J. (2017). Mind: A journey to the heart of being human. W. W. Nortan & Company: New York, NY.
6. Van der Kolk, B. (2014). The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. New York, NY: Penguin Random House LLC.
7. Pizzagalli, D., Regard, M., Lehmann, D. (1999, September 9). Rapid emotional face processing in the human right and left brain hemispheres: An ERP study. Cognitive Neuroscience, 10(13), 2691-2698. 
8. Warner, M., & Wilder, J. (2016). Rare Leadership: 4 Uncommon Habits for Increasing Trust, Joy, and Engagement in People You Lead. Chicago, IL: Moody Publishers.
9. Shaprio, F. (2017). Eye Movement Desensitization and Reprocessing (EMDR) Therapy: Basic Principles, Protocols, and Procedures (3rd ed.). New York, NY: Guilford Publications.
10. Queensland Brain Institute. (n.d.). The limbic system [Blog post]. Qbi.uq.edu.au. Retrieved from https://qbi.uq.edu.au/brain/brain-anatomy/limbic-system
11. Queensland Brain Institute. (n.d.). The forebrain [Blog post]. Qbi.uq.edu.au. Retrieved from https://qbi.uq.edu.au/brain/brain-anatomy/forebrain