People have several different types of memory, including sensory memory, short-term memory, working memory, and long-term memory. Here’s how they differ and how they can be affected by Alzheimer’s disease.
Sensory memories are very brief (about three seconds) recollections of sensory experiences, such as what we just saw or heard. Some people liken sensory memory to a quick snapshot you just experienced but quickly fades away.
Short-term memory is the short period of time in which you can recall information that you just came across. short term Usually includes anything from 30 seconds to several days, depending on who uses the term.
How Alzheimer’s disease affects short-term memory
Some researchers use the term working memory and distinguish it from short-term memory, although the two overlap.Working memory can be defined as our brain’s ability to retain limited information long enough to use it. Working memory helps process thoughts and plans, as well as execute thoughts.
You can think of working memory as your short-term memory, which combines strategies and knowledge from long-term memory banks to help make decisions or calculations.
Working memory is related to executive function, which is often affected in the early stages of Alzheimer’s disease.
How Alzheimer’s Disease Affects Working Memory
Long-term memory includes memories from days to decades. For successful learning, information must be transferred from sensory or short-term memory to long-term memory.
How Alzheimer’s disease affects long-term memory
How does Alzheimer’s disease affect memory?
In Alzheimer’s disease, one of the common early symptoms is short-term memory loss.When discussing Alzheimer’s disease, clinicians often use the term “short-term memory loss” to refer to a period of time ranging from extremely short periods of time, such as 30 seconds, to intermediate periods that may last several days.
People with early symptoms of Alzheimer’s may repeat questions frequently within a few hours, or tell the same story they told five minutes earlier.
This type of short-term memory loss is often one of the first visible signs of cognitive decline in an individual. By contrast, long-term memory in people with early Alzheimer’s disease is often left intact.
Coping with early Alzheimer’s can be challenging. Individuals may know in their long-term memory that they have been diagnosed with Alzheimer’s, and may also be aware of and distressed by their short-term memory deficit. At this stage, it can be helpful to use strategies and techniques to help store information in memory.
Long-term memory is also affected as Alzheimer’s disease progresses to the middle and late stages. Rather than simply forgetting that she had breakfast, a mother with Alzheimer’s may not forget that her own mother died 20 years ago.
During these stages, procedural memory — knowledge about how to do things like walk or ride a bike — declines.This makes activities of daily living (ADL) such as brushing or bathing very difficult, requiring care from a loved one or professional.
During advanced Alzheimer’s disease, it also becomes challenging for individuals to identify people they have known for many years (such as close friends or family members).
Watching your loved one battling memory loss can be hard, but reminding yourself that this is an effect of Alzheimer’s disease, not something of personal choice, may help you cope and respond positively to your loved one.
In the early or even middle stages of Alzheimer’s, people may still be able to learn something (like a routine) if repeated enough. However, as Alzheimer’s disease progresses to its final stages, the ability to not only access old memories but also form new ones is lost.
Understanding the different types of memories and how they are affected by Alzheimer’s disease can be helpful for caregivers and loved ones of people with dementia.
If you notice signs of memory loss in yourself or a loved one, it’s time to make an appointment with your doctor for a physical and evaluation. The appointment can help determine whether memory loss is due to Alzheimer’s disease, another form of dementia, or a disorder that may be reversible if detected and treated.
Frequently Asked Questions
What is sensory memory and why is it important?
Sensory memory is related to the five senses – sight, hearing, smell, touch and taste. Sensory memories are stored briefly upon stimulation of the senses before being converted to short- or long-term memory. Without sensory memory, we have no ability to form memories.
What is short-term memory and why is it important?
Short-term memory is the ability to store small amounts of information in the brain for a short period of time. Also known as primary or active memory, short-term memory is short-lived—about 30 seconds—and limited to between 5 and 9 items. Before memory can be transferred to long-term memory, it is first short-term memory.
What is working memory and why is it important?
Working memory is the small amount of information that can be held and used in the executive function of a task. Working memory is important for executive function, following instructions, and attention.
What is long-term memory and why is it important?
Long-term memory is the ability to store and recall information for later use. It is the largest part of your memory and can be divided into three categories: episodic, procedural, and semantic.
Learning requires long-term memory. New information first passes through the sensory or short-term memory stage. Once translated into long-term memory, the person is able to recall the information later.