What Is Memory?
Memory refers to the processes that are used to acquire, store, retain, and later retrieve information. There are three major processes involved in memory: encoding, storage, and retrieval.
Human memory involves the ability to both preserve and recover information we have learned or experienced. As we all know, however, this is not a flawless process. Sometimes we forget or misremember things. Sometimes things are not properly encoded in memory in the first place.
Memory problems can range from minor annoyances like forgetting where you left your car keys to major diseases, like Alzheimer’s and other kinds of dementia, that affect the quality of life and the ability to function.
The study of human memory has been a subject of science and philosophy for thousands of years and has become one of the major topics of interest within cognitive psychology.
How Memories Are Formed
In order to form new memories, information must be changed into a usable form, which occurs through the process known as encoding. Once the information has been successfully encoded, it must be stored in memory for later use.
Much of this stored memory lies outside of our awareness most of the time, except when we actually need to use it. The retrieval process allows us to bring stored memories into conscious awareness.
How Long Do Memories Last?
Some memories are very brief, just seconds long, and allow us to take in sensory information about the world around us.
Short-term memories are a bit longer and last about 20 to 30 seconds. These memories mostly consist of the information we are currently focusing on and thinking about.
Finally, some memories are capable of enduring much longer, lasting days, weeks, months, or even decades. Most of these long-term memories lie outside of our immediate awareness, but we can draw them into consciousness when they are needed.
To use the information that has been encoded into memory, it first has to be retrieved. There are many factors that can influence how memories are retrieved such as the type of information being used and the retrieval cues that are present.
Of course, this process is not always perfect. Have you ever felt like you had the answer to a question right at the tip of your tongue, but you couldn’t quite remember it? This is an example of a perplexing memory retrieval problem known as lethologica or the tip-of-the-tongue phenomenon.
The ability to access and retrieve information from long-term memory allows us to actually use these memories to make decisions, interact with others, and solve problems. But how is information organized in memory?
One way of thinking about memory organization is known as the semantic network model. This model suggests that certain triggers activate associated memories. A memory of a specific place might activate memories about related things that have occurred in that location. For example, thinking about a particular campus building might trigger memories of attending classes, studying, and socializing with peers.
Types of Memory
While several different models of memory have been proposed, the stage model of memory is often used to explain the basic structure and function of memory. Initially proposed in 1968 by Richard Atkinson and Richard Shiffrin, this theory outlines three separate stages of memory: sensory memory, short-term memory, and long-term memory.
Sensory memoryis the earliest stage of memory. During this stage, sensory information from the environment is stored for a very brief period of time, generally for no longer than a half-second for visual information and 3 or 4 seconds for auditory information. We attend to only certain aspects of this sensory memory, allowing some of this information to pass into the next stage: short-term memory.
Short-term memory, also known as active memory, is the information we are currently aware of or thinking about. In Freudian psychology, this memory would be referred to as the conscious mind. Paying attention to sensory memories generates information in short-term memory.
While many of our short-term memories are quickly forgotten, attending to this information allows it to continue to the next stage: long-term memory. Most of the information stored in active memory will be kept for approximately 20 to 30 seconds.
The term “short-term memory” is often used interchangeably with “working memory,” which refers to the processes that are used to temporarily store, organize, and manipulate information.
Long-term memory refers to the continuing storage of information. In Freudian psychology, long-term memory would be called the preconscious and unconscious. This information is largely outside of our awareness but can be called into working memory to be used when needed. Some of this information is fairly easy to recall, while other memories are much more difficult to access.
Forgetting is a surprisingly common event. Just consider how often you forget someone’s name or overlooked an important appointment. Why do we forget information we have learned in the past? There are four basic explanations for why forgetting occurs:
- Failure to store
- Motivated forgetting
- Retrieval failure
Research has shown that one of the critical factors that influence memory failure is time. Information is often quickly forgotten, particularly if people do not actively review and rehearse the information.
Sometimes information is simply lost from memory and, in other cases, it was never stored correctly in the first place. Sometimes memories compete with one another, making it difficult to remember certain information. In other instances, people actively try to forget things that they simply don’t want to remember.
Memory’s Role in Mental Health
Memory is a key element in certain mental health conditions: Abnormal memory function can contribute to distress, or it can coincide with an underlying disorder. Forgetfulness is associated with depression; connections in memory, such as those involving feared situations or drug-related cues, are an integral part of anxiety and substance use disorders; and post-traumatic symptoms are entwined with the memory of traumatic experiences.
In fact, experiences such as distressing memories and flashbacks are among the core symptoms of post-traumatic stress disorder. For someone with PTSD, a range of cues—including situations, people, or other stimuli related to a traumatic experience in some way—can trigger highly distressing memories, and the person may seek to avoid such reminders.
As a feature of various mental disorders, aberrant or biased memory function can also be a target for treatment. Treatments that involve exposure therapy, for example, are used to help patients reduce the power of trauma-related memories through safe and guided encounters with those memories and stimuli associated with the trauma.
No matter how great your memory is, there are probably a few things you can do to make it even better. Fortunately, cognitive psychologists have discovered a number of techniques that can help improve memory:
- Jot it down. The act of writing with a pen and paper helps implant the memory into your brain—and can also serve as a reminder or reference later on.1
- Attach meaning to it. You can remember something more easily if you attach meaning to it. For instance, if you associate a person you just meet with someone you already know, you may be able to remember their name easier.
- Repeat it. Repetition helps the memory become encoded beyond your short-term memory.
- Group it. Information that is categorized becomes easier to remember and recall. For example, consider the following group of words: Desk, apple, bookshelf, red, plum, table, green, pineapple, purple, chair, peach, yellow. Spend a few seconds reading them, then look away and try to recall and list these words. How did you group the words when you listed them? Most people will list using three different categories: color, furniture, and fruit.
In addition to these techniques, keeping your brain healthy by exercising regularly, maintaining social connections, managing stress, and performing challenging activities (like doing crossword puzzles or playing an instrument) have been proven to help boost memory.