Memories are what make us who we are. They allow us to process the environment around us, make changes to our behavior, and most importantly, give us the context of our lives. Memories stem from the process of our brains interpreting and storing information.
When humans learn something, whether simple or complex, connections are formed between neurons in the brain. These connections are called synapses, and these synapses create new paths between nerve cells throughout the brain. When synapses create new circuits, the brain allows for a multitude of possibilities for new connections; the brain's 100 billion neurons are each capable of making as many as 10,000 connections with other neurons. Depending on how often humans are exposed to an event, these synapses can get stronger or weaker. The more a human is exposed to something, the stronger the connections are in the brain. However, less exposure leads to a weaker connection, reflecting forgetfulness of things we don't encounter much.
The brain stores this information as a mental representation, making it accessible for future use. Various factors influence how the brain retrieves a memory.
Stages of Memory Formation
Sensory register, short-term memory, and long-term memory are the three types of memory processes of the brain.
Sensory Memory
In the sensory memory process, the brain quickly gathers information from the environment through brief visual and auditory cues, known as iconic and echoic memory, respectively. Iconic memory allows a transient visual impression, like recalling an image after looking away, while echoic memory involves briefly retaining sounds, as when understanding spoken words moments after they are heard. Attention acts as a bridge between sensory memory and short-term memory, enabling the information captured by sensory register to begin forming short-term memories.
Short-Term Memory
Short-term memory has two components: traditional short-term memory and working memory. Short-term memory temporarily holds information for quick recall, such as remembering a friend's address long enough to write it down. Working memory, on the other hand, stores information for active manipulation, like keeping track of directions while driving or holding a sequence of steps in mind while following a recipe. Psychologists often focus on improving working memory because it is more under our control and can be actively improved.
Long-Term Memory
Long-term memory is often thought of as a permanent storage in the brain, where memories are kept indefinitely. However, this isn't entirely accurate. While long-term memory allows information to be stored for extended periods, nothing in the brain is completely exempt to change. Memories stored in long-term memory can remain for a short time, like a few days or weeks, or last a lifetime.
When long-term memories form, the hippocampus retrieves information from working memory and begins altering the brain's neural connections. These new links between neurons and synapses remain as long as they continue to be used. Psychologists categorize long-term memory into two types based on duration: recent and remote.
Forgetting
We know that our brains are capable of forming memories that we are typically able to recall. However, sometimes we don't always remember certain memories. Memory is a complex process, but just as important as remembering is the ability to forget. Forgetting can occur for various reasons, whether it's due to a lack of attention or the brain’s inability to reinforce certain memories. Understanding why we forget can help explain how our memory system works and how information is retained or lost over time.
Forgetting can occur due to inattention or because the brain fails to reinforce a memory enough to retain it. Research proposes two primary theories for why memories are forgotten:
The decay theory suggests that if a memory isn't revisited or reinforced, it will gradually fade away.
The interference theory proposes that new information can overwrite old memories, such as forgetting an old password after creating a new one.
There are several factors that contribute to forgetting. These factors include excessive alcohol use, smoking, lack of sleep, illicit drug use, and more.
Conclusion
Memory is a dynamic and complex process involving the creation, storage, and retrieval of information. While memories shape our experiences and behaviors, forgetting is just as crucial, allowing us to filter out irrelevant information. Understanding how memories form, are retained, and sometimes fade offers insights into the brain's exceptional capacity to adapt, learn, and process information.
Works Cited
“How Does Human Memory Work?” ECU Online, 10 Jan. 2024, https://onlineprograms.ecu.edu/blog/how-does-human-memory-work/. Accessed 10 Nov. 2024.
“How Memories Are Made: Stages of Memory Formation.” Lesley University, https://lesley.edu/article/stages-of-memory. Accessed 10 Nov. 2024.
“Inside the Science of Memory.” Johns Hopkins Medicine, 15 Nov. 2021, https://www.hopkinsmedicine.org/health/wellness-and-prevention/inside-the-science-of-memory. Accessed 10 Nov. 2024. Assessed and Endorsed by the MedReport Medical Review Board