It can be fascinating to wonder about the marvels of the human brain. Unlike most other animals, humans are self-aware. We can think, plan, and recall events that have happened in and around our lives. Despite our incredible capacity for thought, how the human brain creates memories and processes thoughts can still be quite a mystery.
How The Brain is Structured
It’s crucial, to begin with, the basic structure of the brain to start to understand how the human mind creates memories and processes thoughts. For the most part, animals all have relatively similar brain form. In this essential form, the innermost parts of the brain are the oldest in and have not changed much over years of evolution.
These inner parts of the brain control our most basic survival instincts such as breathing, resting, moving, and feeding. As you move away from the spinal cord, additional layers provide the capacity for higher thinking and better memory. In humans, our outermost layer of the brain is called the cerebral cortex, and it is incredibly sophisticated.
With such a highly developed outer brain layer we are capable of much more than the most basic survival functions. For example, humans frequently develop intricate social networks, can retain memories for long periods of time and can experience emotions.
How We Form Thoughts
Moving forward from the underlying structure that allows for the formation of higher thinking patterns, we delve further into how thoughts are processed. The brain is composed of specialized cells known as neurons and support cells called glia.
As you probably know, neurons are the cells most commonly associated with the nervous system. However, it is important to note that without glial cells, the neurons in the brain would not be able to function at all. Many different types of glial cells exist in the brain and provide numerous benefits to the neurons.
More specifically, glial cells provide the following benefits to neurons:
- Guide Developing Neurons to Their Destinations
- Protect Neurons from Harmful Ions and Chemicals
- Provide Myelin Sheaths Around Axons
- Modulate Communication Between Nerve Cells
As you can see, these lesser-known cells are incredibly crucial to a fully functioning human brain. In fact, without these essential support cells, humans would not be capable of processing thoughts or forming memories.
Neurons are the specialized cells that receive all forms of sensory input from the external world and communicate that information to the body and brain. Compared to other types of cells, neurons have a unique tree-like shape that fosters the work of delivering information throughout the body.
While much is unknown about the inner workings of the brain, scientists have discovered that neurons behave in a pretty specific manner. There are three main parts to each neuron; the cell body, the dendrites, and the axon. When exposed to an electrical impulse, information moves from the dendrites to the cell body and then to the axon.
Once the electrical impulse moves to the end of the axon, it reaches the synapse. Here the signal moves from one neuron to the next by way of a neurotransmitter. The neurotransmitter stimulates the next neuron, and the process begins again.
When neurons absorb information from the wide variety of stimuli we come in contact with every day, billions of connections can occur through the neural pathways described above. These connections are what lead to our perceptions about the world around us. Furthermore, these connections work together to create our thoughts.
But what happens after the brain has “processed” thought in this manner? Does it all just end there?
How We Store Thoughts
Now that we have outlined a basic understanding of how thoughts come to be, we can continue to work out how the human brain creates memories and processes thoughts. It’s important to understand that neuroscience is a very complicated discipline and is not entirely understood by researchers as of yet.
Most people understand that the process of storing thoughts is what we refer to as memory. However, a much smaller number of people have any real understanding of how our brains take seemingly “simple” thoughts and turn them into memories.
To start our discussion, we will begin by saying that memory, unlike other attributes of the body, is not a defined part of the body. Instead, the word memory refers to the elaborate means of remembering.
A wide array of models have been used to describe the way that memory works in the human brain. However, current researchers are quickly finding that these simplistic notions regarding memory are nowhere near as sophisticated or elusive as the human memory. Today, scientists are finding that it is made up of a complex web of cells placed explicitly around the brain.
Most people have heard the term “short-term memory” at one point in their life or another. However, only a handful of people can give an accurate description of what short-term memory is.
To begin our discussion, we’ll note that short-term memory is also known as active or primary memory. As these names imply, short-term memory is something that we use in our present state of being. Furthermore, it is worth noting that short-term memory is limited in both duration and number of items held.
For most functioning brains, the short-term memory lasts between twenty and thirty seconds. Sometimes this time frame fluctuates in either direction depending upon the circumstances under which information is received. Typically the average human brain can hold between four and nine items in short-term memory.
In contrast to the fading short-term memories that we dispose of quickly, the long-term memory seems to be unlimited regarding the number of items stored. Additionally, long-term memories are typically stored for much more extended periods of time, usually many years. But how exactly does the human brain move items from short-term memory to long-term memory?
Most people are vaguely aware that there are a variety of techniques for committing specific information to memory. For example, people tend to “chunk” information into smaller parts of a larger whole to memorize it. Also, it is common to use rehearsal as a means of committing short-term memory to long-term storage.
Despite the knowledge of these memorization methods, the specific science behind “converting” short-term memories into long-term memories is not well understood. Several working theories try to explain the precise mechanisms of memory. Each potential philosophy is unique, and this particular subject is a matter of much scientific controversy.
Memory Loss and Difficulty
It’s no secret that just as our brains have an incredible capacity to process information and develop memories, they also can “lose” memories. Injury, trauma, and certain illnesses can all affect the way we remember things and even make it seem that certain memories are gone for good. But what exactly happens when we “lose” a memory?
Because the mechanisms regarding thoughts and the way we store memories are not very well understood, it is difficult to say what precisely happens when we forget something. In some cases, memory loss seems to be temporary while in others it looks more permanent. By examining the different causes of memory loss, we can gain some useful insights.
Retrograde vs. Anterograde Amnesia
In movies that feature patients with amnesia, it’s often the case that these characters cannot remember their past. This type of amnesia is medically known as retrograde amnesia. Retrograde amnesia can be caused by disease or injury and deals explicitly with memories stored before illness or injury. The ability to learn new concepts is generally not affected.
In contrast, anterograde amnesia preserves old memories and prevents the development of new memories. Because of the mystery surrounding how the brain stores memories, anterograde amnesia is very difficult to understand. Additionally, this type of amnesia provides a wide array of questions regarding how memories are formed and stored.
Dementia and Alzheimer’s Disease
The term dementia refers to a group of diseases that cause a slow decline in the ability to think and recall past knowledge. Alzheimer’s disease is the most common disorder associated with dementia and also the most common cause of it.
Despite Alzheimer’s disease causing the majority of dementia cases, there are several other causes of dementia. Some of these causes are reversible, suggesting a high degree of plasticity in the brain. However, there is no defined cure for Alzheimer’s disease or dementia in general which highlights our general lack of understanding of the human mind.
Overall, the mechanism that dictates how the human brain creates memories and processes thoughts are complicated. Neuroscientists are continually researching new theories and challenging previous notions regarding the human mind.
As new technologies develop, scientists have high hopes of gaining a better understanding of the brain and all of its intricacies. However, until we can understand the subtle processes that create our ability to think and store information, it is unlikely that we will gain a better understanding of diseases that affect our ability to create and access our memories.