Short-Term Memory
Just as we did in previous posts, we continue to describe the main cognitive functions. Now it’s the time to explore short-term memory. As we will see in the next paragraphs, short-term memory is absolutely necessary in our everyday lives. Without it, it would be impossible to complete many of the activities we normally do. Many of the activities that we perform on a daily basis requires that we retain certain information and that it is “available” to ensure that it can be processed.
On top of that, our lives would be very different if our short-term memory was affected by the simple fact that we would not be able to remember many of the things that have happened to us. This is due to the fact that there is a very strong link between short-term memory and the capability of generating longer duration memories. But, to better understand what are the consequences of having our short-term memory affected and how it can be improved, we first need to understand what is short-term memory. As a result, during the rest of this post, we will explain what exactly is this important type of memory that we all have.
What is Short-Term Memory?
In general, when we talk about short-term memory, we refer to the full cognitive system necessary to process the stimuli collected by our senses during brief spells of time. Short-term memory allows us to store information for short periods of time, that can go from seven to forty seconds. For example, our short-term memory allows us to remember the subject of a conversation in which we are participating. This type of memory requires, of course, other cognitive processes like attention, that allows us to select a part of the stimuli that we collect using our senses.
On the other hand, it is also considered that the amount of information that can be stored with this type of memory is limited. Normally, it is considered that one can store up to seven elements, but the exact amount will depend on each person. In some cases, there are individuals that can retain up to nine elements, while others are only capable of storing five. In general, it is believed that the majority of individuals can store up to seven elements, with a variation of plus/minus two.
Short-Term Memory Loss
In the previous section we explained that an affected short-term memory, or a full loss of short-term memory, can have devastating effects on the ability an individual has to retain and store information. Normally, short-term memory can also discard received information that is considered irrelevant. Or, on the contrary, if there is a strong emotional association or if the stimulus is persistent, it is possible that that information (or memory) goes on to become a part of our general memories or part of a longer duration memory.
In fact, since these two types of memory (short and long-term memory) are directly associated with the learning process, both are very important for all of us. The case of the famous patient is well-known who, after losing the ability to store information, could not learn anything new. This is one of the direct effects of not being able to store information received from the outside world. Other than those individuals with a neurological injury that might have their short-term memory affected, those who suffer from Alzheimer’s disease or from dyslexia might also have a similar impairment.
How to Improve Short-Term Memory
There are several ways in which short-term memory can be improved. However, this recovery will depend on two factors. The first one is the previous state of the short-term memory and, the second one, it level of deterioration when training to improve it starts. If it’s state was low at the moment of the loss, one cannot expect that treatment recovers memory over that point. The same thing happens if treatment is started when there already is an important loss.
In both cases, it is important to train with the different systems in charge of storing the different types of information that we encounter every day. On the one hand, we have the central executive. This system is in charge of regulating short-term memory. We also have the phonological loop. This system stores verbal information. For example, it is responsible for that “internal voice” that we use to repeat something when we want to memorize it. We also have the visuospatial sketchpad that is in charge of visual and spatial information. And, lastly, the episodic buffer. This is the system responsible for storing multiple data and which enables us to have a global memory that brings together the information coming from the other systems.
Exercises to Improve our Memory
Cognitive stimulation uses exercises specifically designed to improve memory. Although it is normally recommended to participate in two to three sessions per week, the ideal session frequency will depend on the needs of each patient. Among the more than 140 cognitive exercises currently available, Rehametrics has thirty exercises designed to stimulate the different types of memory. Many of those exercises were designed to train the systems in charge of the correct functioning of our short-term memory: the central executive, the phonological loop, the visuospatial sketchpad and the episodic buffer. In the next paragraphs, we will describe some of those exercises:
Short-Term Memory: a sequence of elements that can be images or written or heard words will be shown. Afterwards, the same elements will appear again, but one of these elements will be missing. Patients must write the word that corresponds to the missing element.
Working Memory: patients must identify the elements (which can be images or written or heard words) that were shown at the beginning of the task.
Spatial Memory: a matrix with different positions appears on screen. In them, a color, an image or a word can be displayed. Patients must remember the elements and their locations so that they can rebuild the matrix afterwards.
