We are all familiar with the concepts of short-term and long-term memories, which cognitive psychology has long presented to us as our two major types of temporal memories. Over time, our knowledge of these two memories has been refined, primarily through neuroscience, and we now know a little more about how they work. So let’s take a look at the two facets of our short-term memory!
Sometimes called “working memory,” short-term memory is designed to store and retrieve processed information in less than a minute. For example, it allows us to remember a name, a number, a list of items, etc. In addition, however, we have another memory, called “sensory,” which functions in the short term as the first filter for our memory functions.
Sensory (or perceptual) memory
A filter of our senses. Sensory memory is the first step in processing information to be memorized: it is a filter through which all the stimuli coming from the outside through our senses (sight, hearing, touch, smell and taste) pass.
Plural memory. Since each sense has its system, its circuit linked to a specific area of the cerebral cortex, we can speak of visual, auditory, olfactory, gustatory and tactile memories.
Interconnected memory. Sensory memory is not limited to a single brain region but is interconnected with the other memories, whose proper functioning it contributes to. By also recording the emotions and sensations linked to the sensory information perceived, this memory allows us to recognize our environment and gives meaning to future events.
Hyper-fast sorter. To avoid being submerged, this memory — which does not require our attention! — must sort itself out and empty itself hyper rapidly. Our brain receives the equivalent of an entire encyclopedia to read per minute from our sense of sight alone. The retention time of the information in this memory oscillates from a few hundred milliseconds to one or two seconds.
Electrical signals. Sensory receptors transform the chemical or physical energy of stimuli into electrical signals (nerve impulses). At this stage, we are not yet talking about sense memory as described by Marcel Proust and which requires a more advanced level of information integration.
Towards long-term memory. Electrical signals follow different pathways to activate specific regions of the brain and be interpreted accordingly. The information that is deemed relevant is then processed to be stored (encoded), then transmitted to short-term memory, a more stable memory, and eventually to long-term memory.
The one that juggles with the immediate. Working memory is an updated concept of short-term memory. It doesn’t just temporarily hold new information before it goes into long-term memory; it manipulates it in processes such as reasoning, comprehension and learning.
Multitasking memory. Also known as “immediate” memory, this memory comprises several independent systems that allow for the execution of various tasks simultaneously and involves a dialogue between three brain areas: the prefrontal cortex, the frontal eye fields and the lateral intraparietal area.
Limited memory. We could only consciously memorize 4 or 5 items. Recently, researchers have discovered that when the working memory is overloaded, the exchanges between the three brain areas involved are short-circuited.