The act of remembering something is a process, and to improve upon the process it’s crucial to understand each of its steps. Sensory memory is the very first stage of remembering things: it is the experience that is picked up by our senses of taste, touch, sight, hearing and smell. Though many of our long term memories may be interwoven with these sensory inputs, that does not mean that sensory memory is our strongest memory tool — it is only our first. In fact, we remember only a tiny fraction of the sensory information that we take in. Most of what we see or hear, taste or touch is forgotten almost immediately unless we pay attention to it. The smells and sounds that we can later evoke are those that we have attended to, and which have moved beyond sensory memory into short term memory. Later, if the information that was sensed and attended to is rehearsed, it enters into our long term memory. (Simply Psychology)
Understanding What Sensory Memory Is
Mention sensory memory to the average person and they are likely to think of the smell of their grandmother’s perfume or their ability to remember the words to songs, but that’s not what sensory memory is. Sensory memory is the area of the memory where all of the information that enters our consciousness on a constant and automatic basis is first experienced. We have no control over these experiences: they are just raw data that our brains take in through our senses. Each sensation is stored in its own, separate sensory modality for only the briefest period of time. The question of whether it is stored in short term memory is a question of whether the data that has been taken in is relevant. If it is important enough to hold on to, then it is transferred into working memory, where it can be encoded and rehearsed for later retrieval. What is not relevant deteriorates in a matter of seconds. (Psychestudy)
The Different Sensory Memory Modalities
We have five different senses, and each has a corresponding sensory memory modality where the sensations that we experience are stored upon being registered by our brains. They are:
- Echoic memory (Auditory, or hearing sensory input)
- Gustatory memory (Input related to the sense of taste)
- Haptic memory (Tactile, or touch, sensory input)
- Iconic memory (Visual sensory input from the eyes)
- Olfactory memory (Input related to the sense of smell)
Each of the modalities stores the information that it takes in for a varying amount of time, but in each case it is necessarily brief – after all, we are constantly taking in more information, so what is not registered as important almost immediately gets discarded to make room for new sensory memories. Our sensory memory represents our continuing experience of the world.
How Long Do Sensory Memories Stay with Us?
The notion of sensory memory was first explained by an 18th century mathematician named Johann Andreas Segner, who used a lit sparkler and a wheel to measure the length of time that the image of the light remained in sensory memory. Though this experiment was primitive, it was proven to be extremely accurate two hundred years later when George Sperling conducted an experiment in 1960 using a letter matrix to determine that iconic memory — or the memory of what we see — deteriorates after approximately 250 to 500 milliseconds. A more modern study using neuroimaging was able to determine that that echoic, or auditory sensory memories are retained for between two and five seconds after the sound stimulus is experienced. Haptic memory, or the memory of touch, is communicated through the skin and travels along our nerves and spinal cord to the brain. Its duration has been measured at approximately one to two seconds. (TodayIFoundOut)
