YOUR BRAIN'S MEMORY BANK

7. How your Brain Remembers (memory)

Brain Science:

It is common knowledge that our memories work on two different levels: short term and long term memory. Before an experience can become part your memory there is first sensory stage that lasts a fraction of a second. The experience is sort of front loaded in the sensory part of the brain. Sensory memory allows a perception of an experience to be retained after the stimulation is over. This is only a fraction of the second and then it is moved to short term memory. Above is a simple model of the brain.

Short term memory is closely linked to the functioning of the hippocampus, while long term memory is closely related to the functions of the outer layer of the brain, your cortex. The hippocampus must send the memory impulse to the cortex (outer layer of brain) to create a memory that lasts. Long term memory includes all information you can recall. Unlike sensory and short term memory, your long term memory allows us to recall unlimited amounts of information indefinitely. Once stored in the cortex, memories must be retrieved. When you call up memory, you first fetch the information at an unconscious level and then willfully drop it in your conscious mind. The networking of information flowing back and forth between the cortex and hippocampus is complex but results in a retrieval to and from the hippocampus. This involves constant perceiving, processing, comparing new memories with old and being able to retrieve and then recall for action. While the functions of memory are facilitated in areas throughout the brain, the hippocampus is your brain’s memory center. With the help of the brains frontal cortex, your hippocampus takes the helm to analyze various sensory inputs and evaluate whether they are worth remembering. ( For the purpose of understanding cognitive decline, next time we will go into how this occurs at a biochemical level. ) Suffice it to say, your memory is in a constant state of change.

Brain facts:

• Studies show that as your hippocampus shrinks, so does your memory.

• Most of us can only hold about seven items of information in your short term memory. Hence we typically break up numbers in groupings of seven or less. Example, 812-201-5698.

• Most people see themselves as having either a good or bad memory, but the truth is we each are fairly adept at remembering some types of things and not so great at remembering others.

• The hippocampus, the part of the brain considered the memory center, has been documented to be significantly larger in people whose jobs have high cognitive demands, compared to the average person.

• Studies show that as your hippocampus shrinks, so does your memory.

So What:

Let’s talk about alcohol. Alcohol puts a glitch in the process of the brain. It interferes with biochemical processes of the brain. Specifically, it changes the composition of the chemical compounds around the synapses and dendrites of neurons. the change in chemical composition causes resistance to the electro chemical impulse flow. In other words It interferes with the back and forth flow between the hippocampus and cortex. For someone who is intoxicated, the encoding into long term memory often does not occur very well, if at all. And that is why, days later, someone may have a hard time remembering something that was so vivid earlier when the memory was still in short term storage. In these cases, they can’t retrieve the memory from the cortex (long term memory) because it was never there in first place. (You know I always hated it when Sue used to remind me of what I had done the night before. I preferred it not be in my long term memory!)