Defining The Different Types Of Memory
Updated December 19, 2018
Reviewer Aaron Horn
When you think about the term memory and your memory, you may innately know that this construct represents all the things you can remember from throughout your life. Have you ever stopped to think that memory involves so many different particular types of things?
Indeed, memory does involve many different forms of information. Your memory (just like everyone else's) includes your knowledge of words, facts, figures, how to do various tasks, and of course, your memories for the many events you have experienced throughout your life.
Defining memory and the memory types is therefore not as easy as it may seem. There are four different main types of memory that researchers and psychologists have been able to define. Learn more about each of these memory types and some of the specific memory subtypes too:
Sensory memory is the first system of memory that information enters. At this level, that information is pure sensory data from the five senses of sight, hearing, taste, smell, and touch. As such, this system has an incredibly large capacity. However, information remains only briefly before it is filtered through. If the information seems important, it proceeds through to be transferred to short-term memory.
Visual sensory information is called iconic memory, and this form of sensory memory is one of the most studied. Echoic memory or memory for the sense of hearing is also well studied. Haptic memory is the technical term for memory about the sense of touch. This includes information gleaned from the body receptors regarding pain, pressure, and itching, among other sensations. Research on the way that this memory subsystem works is relatively new and still seeking to discern how haptic memory works.
Your short-term memory receives information from your sensory memory. While your sensory memory has a large and brief capacity, your short-term memory can hold only a limited amount of information. Information will also leave short-term memory quickly, unless you actively do something with it, to hold it there, and eventually move it to long-term memory.
Research has shown that short-term memory can generally hold five to nine pieces of information. One strategy for holding more information in short-term memory is to engage in an approach called chunking. This is where you combine the smaller pieces of information into larger ones, thus reducing the total number of chunks you must remember. For example, if you need to recall a phone number, instead of trying to remember ten distinct digits, you might make them into double-digit chunks.
To hold information in short-term memory for a longer period, you can also engage in the process of rehearsal. Chances are you have done this in the past without even realizing it. This is where you repeat the information over and over again in your mind, to hold it there for long. For example, you might do this if you are told a phone number and need to retrieve your phone before you can dial.
While some people conflate short-term memory with working memory, they are considered separate systems. The working memory system is considered to hold information that is actively being manipulated for processing. That processing may be done with the intent to make decisions or select behavioral outcomes. Similar to short-term memory, working memory has a fairly limited capacity.
It is hypothesized that working memory is comprised of subsystems. This was illustrated in Baddeley's model of working memory. Baddeley and his colleague, Hitch, suggested there may be three components. One is named the central executive because that system seems to govern the others. Another, the phonological loop, seems to manage language. The third, the visuospatial sketchpad, seems to be subservient to the others. It is proposed that visual and spatial information can be processed here. A fourth component was also theorized as the episodic buffer, which may temporarily work with other information and may help link working memory to long-term memory.
It is known that information can move from short-term memory to long-term memory if your brain deems it important enough to hold onto. Research suggests that much of this transference occurs during sleep, which is why the right quality and quantity of sleep is crucial for learning. Your long-term memory is that component of the total memory system that seems to have unlimited capacity and duration. It is also the component that is the most complex and complicated, with several subsystems.
Within the broader long-term memory system, implicit memories are those that occur with less intentionality, meaning there was not necessarily any intention to learn and put that information into long-term memory or to later recall that information. For example, one specific type of implicit memory is a procedural memory, which involves remembering how to do certain actions and tasks.
Otherwise known as declarative memory, explicit memories are those that require conscious effort to put into memory and also to later recall. This type of long-term memory is then further divided.
Long-term memory for information is known as semantic memory. This is the type of information you often learn in school and must recall for various school/work tasks.
Your recollection of specific events and their accompanying information (such as the name of someone you previously met) is called episodic memory. This type of memory declines with age.
Similar to episodic memory, autobiographical memory is knowledge about personal events and experiences. Such memories may differ from others because they are unique to each person.
Disorders Of Memory And The Effects On Different Types Of Memory
Anyone can have the occasional memory problem, such as forgetting a word, forgetting where you left an item, or forgetting to complete some task. Such problems may happen more often when under stress, when sick, or with increasing age. Certain disorders can also significantly affect memory.
Certain diseases are considered neurodegenerative because they involve the breakdown of the brain over time. Such disorders can include forms of dementia, including Alzheimer's Disease. Other disorders include Huntington's Disease, Parkinson's Disease, and Multiple Sclerosis. In some of these disorders, long-term memory loss is a secondary symptom due to general neural deterioration. All these disorders are irreversible, and there currently are no known cures.
Traumatic Brain Injury
If someone sustains a significant head injury, they may incur traumatic brain injury. This can occur during car accidents or serious falls. Depending on the nature of the injury, various parts of the brain may be damaged. In some of these cases, amnesia can occur, which may affect the recall of past events or the ability to put new information into long-term memory. In some instances, a person may require brain surgery that can cause similar side effects.
Emotion, Memory, And Mental Health
During certain highly emotional incidents, people may form a "flashbulb memory." These memories are almost like photographs with the recollection of a high level of detail for the incident. This often occurs after upsetting events. For example, people close to a bombing will have very vivid memories of the incident.
Having heightened emotions so closely attached to memory can lead to certain mental health conditions. Immediately after a traumatic event, a person may experience Acute Stress Disorder. With immediate support and psychological treatment, the symptoms may resolve. If the symptoms persist, the person may eventually meet criteria for Post-Traumatic Stress Disorder (PTSD).
The symptoms of PTSD include flashbacks and nightmares. Individuals with PTSD are often upset when they see stimuli that remind them of the trauma. Over time, the condition can be debilitating. It can affect a person's ability to function at home and outside of the home. Generally, treatment is needed. Mental health professionals can take varied approaches to help the person put the incident behind them. People with PTSD can recover and go on to live a normal life even after difficult events.
When you read about memory, it can sound like a very technical and even sterile thing. However, in real life, memory is complex and sometimes challenging. Some people do experience difficult events and are left with painful memories that they may struggle to escape from. Others may want to improve their memory to aid their success in various areas of life, such as at work and home.
If you have painful memories that you want to leave behind, you might benefit from mental health counseling. Trained therapists and counselors can assist people in processing through difficult memories so that they can have less impact on their life. If you find your memory is not as strong as you would like, mental health professionals can assist with that too. You can seek out a therapist with the training and experience to help you with your particular mental health and emotional needs.
As you seek out a mental health provider to assist you with your memory-related problems, you will want to ask about their training and experiences in working with that condition. Ask about their approach to working with painful memories or in working to improve memory functioning.