The brain develops from the bottom up. The first thing to develop is the brain stem or the reptilian brain, as some people might call it. This area is responsible for our bodily functions.
It tells us when to regulate our temperature, when to sleep and when to eat. The next important part of our brains to develop is the limbic system, or what some people might call the mammalian part of the brain. The limbic system supports a variety of functions including; emotion behaviour, motivation and long-term memory.
The next part of the brain to develop is the cortex which is the outer layer of the brain. This is sometimes considered the human part because humans are one of the only mammals that develop this part of the brain. This part of the brain is responsible for how we as humans were able to develop language, have thoughts, self-awareness, perception and consciousness.
Also the cortex plays a key role in integrating the central nervous system and functions of memory. The last and most advanced part of the brain to develop is the prefrontal cortex which is considered the executive functioning part of the brain. For some people this part doesn't fully develop until they're in their mid to late 20s.
The prefrontal cortex helps us to think through cause and effect, the ability to plan for the future, set goals and understand the consequences of our actions. It's also responsible for the ability to moderate social behaviour when we're in a stressful situation. Part of our limbic system called the amygdala sets off an alarm bell response to let us know we're in danger and we need to do something about it.
When this happens the brain floods with a hormone called cortisol so the body knows that something needs to be done. The most common responses to a stressful or dangerous situation are some you might be familiar with. Fight.
Flight. Freeze. Or submit.
This is an inbuilt system of survival to keep us safe when we're in danger like when our ancestors might have had to decide whether to stand their ground and fight against a large predator, or run away. A stress response is a healthy normal part of being a human. It lets us know that our bodies are working and keeping us safe.
If a person is exposed to a highly stressful or traumatic event or they have continual exposure to stressful events like abuse or neglect their alarm system might become overactive. It might be always switched on as if there was a risk of danger or threat at all times. For a child this might affect how their brain develops.
This is especially the case if it's in the context of stress or trauma events by a primary caregiver. In these cases the child might develop an understanding of the world as an unsafe and dangerous place even when they are in a safe situation. Sometimes this is called hyper vigilance.
It means being on edge or aware of danger at all times. Being exposed to stressful and traumatic events on a regular basis can also have a significant impact on neural connections in the memory centre. It can even change the way we remember actual events.
People use alcohol and other drugs for a variety of reasons. When someone's experienced trauma they might be in a constant state of fight-or-flight and so might use substances to help move them out of their stress response state. We also know that substance use can affect the way that our brain functions.
Chemicals from substances cross the blood-brain barrier and can either stimulate or depress different parts of the central nervous system affecting how the person feels thinks and acts. Similar to cortisol flooding the brain in the stress response chemicals from alcohol and other drugs can also affect neural pathways and the way the person might make decisions or remember events. Luckily neural pathways have the lifelong ability to form and change.
You might have heard this referred to as neural plasticity. Through developing a better understanding of the brain and the way trauma and alcohol and other drugs affect neural pathways clients can be better informed and empowered this is an intervention itself called psychoeducation.
