What Is Sensory Memory?
Sensory Memory is a very brief recall of a sensory experience. For example, have you ever had it where someone said something to you and you responded with “What?” or "Pardon Me?" Before the person was able to repeat it, you may have re-heard what they said and it almost seemed like an echo. The auditory sensory memory thus is aptly named the echoic memory, while the visual sensory memory is called the iconic memory. Sensory memories typically last just a couple of seconds.
How Does Alzheimer's and Other Dementia Affect Sensory Memory?
Research shows that sensory memories, specifically iconic (visual) memories, last for a shorter time in people with mild cognitive impairment than the general population. It's likely to assume then that this is also true for those who have been diagnosed with Alzheimer's disease since mild cognitive impairment is present in the early stages of Alzheimer's.
How Does Attention Affect Sensory Memory?
Our brains are filled with many sensory memories that are briefly present for a second or two. Fortunately, we don't store all of those things in our short or long term memories; otherwise, our brains would be overflowing with irrelevant information.
For example, think about how many houses you passed on your way home today. Do you know what color they each were? Chances are, your answer would only be a random guess. However, if you consciously paid attention to the colors of the houses, you would be more likely to place some of that information into your short-term and then possibly in your long-term memory. Making a conscious effort to pay attention can increase our awareness and memory of sensory experiences.
WorsleySchool.net. Memory. Accessed January 28, 2012. http://www.worsleyschool.net/science/files/memory/page.html
Zhong-Lin Lu,James Neuse,Stephen Madigan, and Barbara Anne Dosher. Fast decay of iconic memory in observers with mild cognitive impairments. Accessed January 28, 2012. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC547847/