Sensory memory is very short
and keeps impressions only for several milliseconds, or up to three seconds. If
one does not pay attention to information those few seconds and it is not
recognized, it disappears from consciousness. Human consciousness can keep up
to 22 information units. One cannot remember what one was reading, because two
controlling processes (attention and recognition that determine what will be
that sensory information) did not participate.
Only about one third of
information gets to sensory memory. Our attention records changes in the
environment. Drastic changes in it (sound, smells, lights) causes us to lose
attention and get distracted. Level of distraction can be very different. We
always choose information that is interesting for us as we assume it may be
useful for us. If a meeting is boring for you it is highly possible that you
will fall asleep.
It matches instantaneous (direct) perception
memory, which means, what senses of our hands transmit. It
is due to interference, which distracts attention and hinders to repeat events
in thoughts. Sensory memory is very fragile – each new sensory sensation is
dispersed in two minutes. However, sensory memory may sometimes surprise by the
exactness of remembering, which arises so clearly as if the facts were
photographed.
Whether we remember impressions that
„run through“ our brains depends on sensory memory. When special attention is
aroused and appropriate associations made, impressions go to short term memory.