Imagine that your brain is like a forest
There is a vast interconnectedness of leaves, branches, and underbrush. You decide one day to carve a path through this forest. You pull out your machete and begin hacking away at the branches and underbrush. Pretty soon you have a rudimentary path beginning to take shape, it has taken some effort but you can begin traveling through this forest. Now, every subsequent time you decide to travel down this path, the way becomes clearer and easier. Our brains operate in much the same way. The pathways of our brain are the ways we think, and the more we think a specific way the more we strengthen that pathway.
Another analogy: when water runs down a hillside it begins to carve out channels to flow through. Now, every time water runs down that hillside it will tend towards those channels, and it will widen those channels over time. It is the same when I am angry. If I continue to entertain the anger thoughts of anger will strengthen. We reinforce thought patterns by continuing in those thought patterns.
These are simple analogies for a very complex issue, but they serve to illustrate a point about how we think. The more we think and respond to something the easier it becomes to think and respond to that thing.
The brain is made up of a complex system of neurons, and it is estimated that there are somewhere between a billion and a trillion neurons in any given brain. The makeup of a neuron resembles the structure of a tree. A neuron consists of a body (called the soma), the branches (called dendrites), and the trunk (called the axon). The dendrites act like tree branches connected to the forest of your mind. These tree branches, or dendrites, seek information from other neurons and transmit the information to the soma where it is processed (i.e. tree branches into the tree). If the soma decides to fire based on the information the dendrite gathers, the entire neuron sends a signal up the axon (tree trunk). Each neuron is interconnected through points called synaptic clefts (picture roots interspersed with other tree roots). This short video does a good job of summing it up:
Neuroscience: The Neuron
The nature of the brain is to strengthen this connection between the synaptic clefts and the dendrites. These are the transmitters and the receptors of your brain. The way in which they are connected together is the way in which a memory is stored. These connections strengthen the channel of the memory with each recall.
Everything that happens to you causes your neurons to form in a specific way. The way you respond internally to each external circumstance begins to shape how your brain processes each subsequent circumstance. Just as each neuron resembles a tree, so the brain resembles a forest. Connections between neurons are formed and strengthened by habitual responses. Neurons form a path through the brain that is strengthened every subsequent time that thought process fires. These systems of neurons, resembling forests of interconnected branches develop over time and play a part in determining the way you tend to think.
A memory is formed when enough neurons firing develop connections to each other. We recall memories when enough of those neurons fire and create what is called a memory state. In other words, the way you experience the world from birth creates your neural networks, and this begins to determine how you will see the world. Your experiences form your brain, and these experiences in turn become your memories. The way you think is a by-product of these interconnected neurons.
Jesus seems to allude to the passage in Matthew 7 regarding dealing with the log in your own eye:
“And why do you look on the splinter that is in your brother's eye, but do not consider the beam that is in your own eye?Or how will you say to your brother, Let me pull the splinter out of your eye; and, behold, a beam is in your own eye?Hypocrite! First cast the beam out of your own eye, and then you shall see clearly to cast the splinter out of your brother's eye.” Matthew 7:3-5
It sure looks like everyone has a splinter in their eye if you have a log in your own. The log hinders you from seeing anything clearly. Your filter, or your log, develops at a young age when the neurons in your brain begin forming into specific patterns.
Why is this important?
If you were yelled at by your parents, chances are every subsequent time you are yelled at, some part of that original network of neurons is helping to dictate your response. If your parents were distant and failed to show you the love that a child needs, every time you were to attempt to love someone, some of those neurons that developed at a young age will fire and influence your response through the memory state the brain has then achieved. For instance, Scott Peck states in his book The People of the Lie,
"Whenever there is a major deficit in parental love, the child will, in all likelihood, respond to that deficit by assuming itself to be the cause of the deficit, thereby developing an unrealistically negative self-image.”
The way in which you were treated as a young child has direct ramifications on the development of your brain. This is also true of every age of development we go through, but pain experienced in childhood presents particular difficulties in regards to your eventual makeup.
As a young child, your brain development is on overdrive. From the ages 0-3 your brain will produce more neurons than at any other stage of your life, and by the age of 3 you will have more neurons than at any other age in your life. The brain of a child goes through specific developmental stages and absent the proper care and guidance of a mother and father, the child can be stunted in its developmental cycle.
There are generally two types of trauma all children are subject to, trauma of intent and trauma of neglect. Traumas of intent are the things that never should happen to us, physical, sexual, and verbal abuse, among others. Traumas of neglect are the absence of the things we need to develop into good and wholesome adults. Traumas of neglect produce difficulty in relationship later in life. How can one trust or love if they were shown in early stages of brain development that they were untrustworthy or unlovely? Or that others are untrustworthy and unlovely? Traumas of intent create fear. They leave a lingering, maligning presence in the thoughts that eventually, everything will crumble. Those who have suffered from traumas of intent doubt that the present they live in will continue to be peaceful.
These go a long way to explaining the physiological reality to the log in your eye. The way your brain is formed will cause you to see people in ways they simply are not. You will see a splinter when in fact it is your own piece of wood.
Why do we find it so difficult to let go of the hurts and wounds in our past?
Because we have continued to strengthen them by unknowingly responding to them in subsequent circumstances. Our framework for responding to a husband or wife, a son or daughter, a father or mother, has been in part dictated by how our brain has been formed. The way your neural networks were developed over time and strengthened over time help to form your worldview. Why do people see the world so differently? Because they have had differing and unique experiences that helps to form the makeup of their brain.
This then highlights the need to “take every thought captive”, because, by doing so, you can literally begin to reform the neural networks that make up your brain. If you allow it, God will begin to form within you a template for your healing. Why do you think he comes to you as a father (Matthew 23:9), mother (Isaiah 66:13), brother (Romans 8:29), lover (1 John 4:8), and friend (John 15:15)?