This is the third article in a series on senior moments abstracted from my book, Preventing Senior Moments: How to Stay Sharp Into Your Nineties and Beyond.

Memory is a phenomenon as mysterious as the universe. Some believe even more so. Everything we do, every thought we ever had, is produced by the human brain, but exactly how it operates is a mystery. What is exciting for researchers is that the more they probe its secrets, the more surprises they find. One of the most basic is that there are five types of memory.

Think of memories as three-dimensional pictures with sounds, tactile sensations, and odors. While some are fleeting, such as the name of someone you just met, others seem to be cemented into your brain as if epoxy set them.

Sensory (Iconic)

Your brain, like a camera, captures everything to which it attends, similar to a video camera that records everything within the lens’ focus. This endless recording process is called sensory or iconic memory. It occurs whenever we see, smell, hear, and touch. The image or sensation we experience in each of these senses momentarily stays in place before it moves to an area in the brain thought responsible for creating short-term memories.

You and a friend observe a homeless man dressed in bizarre clothing pulling along two shopping carts. He disappears, and your friend asks you what you think about what you just saw. You comment on the movement of the cart’s wheels as they disappear from your mental image.

Short Term

What is short-term memory? You would hope that since we are dealing with neurology, there would be a universal definition everyone could use to avoid confusion. Unfortunately, there is not. Some researchers define short-term memory as impressions that last from about 20 to 30 seconds.  Others are more generous, asserting that short-term memory is everything up to sleep when the brain consolidates them into long-term memories. 

Researchers frustrated with the “slice and dice approach” discard time as a method for classifying memories and instead focus on where memories live.  To add to the confusion, some neuroscientists insist that the amount of information the brain stores differentiates short-term from long-term memory—a little for the short-term, a lot for the long-term.

You are at a party, and a person introduces herself to you. Ten minutes later, she comes back and asks to be introduced to a person you are with. You can’t remember even the first letter of her name.

Long-Term

Defining long-term memory is fraught with the same type of problems as describing short-term memory. Some researchers maintain that long-term memory is anything that occurred moments, hours, or decades ago. Others believe long-term memories are those that follow sleep.

Friends gather and talk about the great 60^th birthday party they gave you a few years ago. You become concerned when you have no recollection of it.

Sequential

Sequential memory refers to behaviors that require multiple steps, with each new step dependent upon finishing the prior one.  It is the type of memory necessary to complete a multi-step project, like putting together your grandson’s bicycle.

You are working in your home office and realize you are getting tired, so you head to the kitchen for a cup of coffee. Once there, you can’t remember why you left your office.

Working (Executive Function)

“Working memory” or “executive function” refers to the brain’s ability to process, hold, and manipulate information that resides in sensory, short, sequential, and long-term memory.  Working memory or executive function is illustrated by what a cook must do to make an omelet. 

To cook an omelet, the brain searches for information in its long-term memory, such as the importance of cracking eggs without getting pieces of the shell in the mixture, the need to butter the pan, etc. Other bits of information will come from short-term memory, such as where you put the eggs after today’s shopping, and others involving the sequential steps necessary to go from cracking eggs to eating the omelet.

The Takeaway

Although memory problems are involved in many senior moments, they don’t cause their occurrence in all, and when they are present, they can take the form of a problem in any of the five types of memory.

In Senior Moments: 4. Slowing Down, you will learn one of the most effective methods for preventing senior moments.