Classification of Memory - Sensory Memory

Sensory Memory usually only lasts a second and at the very most it lasts two seconds. It has a very short life, and the brain chooses to discard most of the information that is in our sensory memory. Attention is what causes our brain to change this sensory memory into STM (short term memory). When we have an attention to something it becomes more relevant and we used it in our STM's

This is taken from wiki and explains one of the first experiments into discovering sensory memory

One of the earliest investigations into this phenomenon was in 1740 by Johann Andreas Segner(1704 - 1777) the German physicist and mathematician. In an experiment Segner attached a glowing coal to a cartwheel and rotated the wheel at increasing speed until an unbroken circle of light was perceived by the observer. He calculated that the glowing coal needed to make a complete circle in under 100ms to achieve this effect.

Examples of sensory memory was found at http://library.thinkquest.org/C0110291/basic/brain/sensory.php

• You lose concentration in class during a lecture. Suddenly you hear a significant word and return your focus to the lecture. You should be able to remember what was said just before the key word since it is in your sensory register.

• Your ability to see motion can be attributed to sensory memory. An image previously seen must be stored long enough to compare to the new image. Visual processing in the brain works like watching a cartoon -- you see one frame at a time.

• If someone is reading to you, you must be able to remember the words at the beginning of a sentence in order to understand the sentence as a whole. These words are held in a relatively unprocessed sensory memory.

I find the second statement VERY helpful, and it relates to my initial idea of using burst frame animation. The fact the we process 'a frame' at a time, almost like watching a cartoon is something I need to look into more to produce ideas. This statement will help for the visual style I will be looking to use, but will have little to do with the actually content, only the way it would be presented.

If I create a video piece of work it will need to be complemented with audio and looking into how the brain processes sounds is also useful. The way you remember a second before the word that caught your attention is important for this.

It’s interesting its almost like memory is in blocks and is something that wanted to be remembered the whole block is then transferred into the STM. You can’t single out the one sound that got your attention. It seems to be more time based.

This is all in terms of short memory in relation to sensory memory. LTM (long term memory) is a little different.

Different stimuli have different durations. Also take from the same site explains these 2.

Your brain can take in a lot of information fairly accurately, but this information is not processed much at all, and it does not remain in sensory memory very long. Exactly how long information can be stored in sensory memory differs according to source of the sensory information being remembered:

• iconic memory (visual sensory memory) - less than one second
• echoic memory (auditory sensory memory) - less than four seconds

This is information is useful because it shows that different stimuli had a duration. If I was to make an Audio and Visual piece of work, I could use this to help me get across the idea of memory.

If for a moment the person was to record their sensory information into a way it could be recorded permanently, for others to see. As an example the one second of information in the sensory image is photographed, and then the audio is played over the top of the image with 3 seconds of audio left playing in the dark. I have written this idea into my notebook with examples and sketches of how it could look as in installation piece of work. I have also looked at how 1 second is perceived e.g. frame rate (30 images to show the motion of a 1 second image)

What happens next?

Our brain must quickly decide what information will be processed enough to remain in short term memory and what information will be discarded. Less than 99 percent of sensory information is passed on to short term memory. Two encoding processes by which we transfer information from sensory to short term memory are selective attention and feature extraction.

• Selective attention occurs when we notice important information necessary to meet our basic needs or our own interests.

• Feature extraction would be observing things as unusual, or "out of the ordinary."

From here I have learnt that attention is what causes the transferring of sensory memory into STM. Depending on what our brains need and weather something is not the norm.


There is a really interesting part of this website which explains an effect of sensory memory

Instructions: Hold your hand up in front of your face and wave it up and down.

Questions: What do you observe? Is this different from what you expected? If so, how?

Discussion: You are able to see where your hand was before you moved it, so it looks like you have more than five fingers. Your eyes are taking in the new image of where the hand has moved to while your visual sensory memory allows you to still see where the hand was just an instant before.


The ability to see where something has just been is from sensory memory. Sensory memory only lasts a few seconds but it allows us to see where something has just been by remembering it.

I ask myself the question does this mean we are looking into the past? Or simple remembering the past as it was just a second ago.

The memory is as strong as it has just happened that nothing can confuse is. With long-term memory we might forget certain colours or objects as we might be recalling from an event that happened a long time ago.

From this site http://www.nwlink.com/~donclark/hrd/learning/memory.html

It briefly talks about working memory were the repetition of something keeps it in our memory for use. We might not always remember the number to help is to not forget it is kept at to our attention by repletion. An example of this would be to remember a phone number. By repeating the numbers it almost (and I use the word lightly) 'refreshes' the information.

The site also references the human brain to artificial memory. It also links the way human memory is in blocks like I previously said.

Works like RAM memory in computers; provides a working space. Is thought to be 7 bits in length, that is, we normally only remember 7 items. STM is vulnerable to interruption or interference.

I found some more information which re-touches on the previous research of recalling information from sensory memory. Taken directly from http://encarta.msn.com/encyclopedia_761578303/Memory_(psychology).html

American psychologist George Sperling demonstrated the existence of sensory memory in an experiment in 1960. Sperling asked subjects in the experiment to look at a blank screen. Then he flashed an array of 12 letters on the screen for one-twentieth of a second, arranged in the following pattern:

Subjects were then asked to recall as many letters from the image as they could. Most could only recall four or five letters accurately. Subjects knew they had seen more letters, but they were unable to name them. Sperling hypothesized that the entire letter-array image registered briefly in sensory memory, but the image faded too quickly for subjects to “see” all the letters. To test this idea, he conducted another experiment in which he sounded a tone immediately after flashing the image on the screen. A high tone directed subjects to report the letters in the top row, a medium tone cued subjects to report the middle row, and a low tone directed subjects to report letters in the bottom row. Sperling found that subjects could accurately recall the letters in each row most of the time, no matter which row the tone specified. Thus, all of the letters were momentarily available in sensory memory.

I found this interesting because it shows a link between the audio and the visual. The audio helped people to remember the visual. This is an interesting idea which I could create a piece of work showing the effects of audio on an image. The audio would directly affect what parts of the image is visible and the duration of image.