Educators educating Educators

Jul 21

Insights into S-T Memory

For further insights into this topic, refer to the following sections in Long-Term Memory: Nobel Prize, Forgetting Curve, Memory Recall, and Long-Term Memory Happens Here

Memory Overview


Emotions or repetition turns an experience into a long-term memory.  The memories of a salient or traumatic event, such as the September 11 terrorist attacks, and those of something we do repeatedly, such as ride a bike, are very difference.  The former, which are memories of facts, people, events, things, and unique experiences are known as explicit or declarative.  The latter, the memories of how to do things, are known as procedural or implicit: They are the things we do without having to think about them.

We remember the facts important to our lives and the tasks that we repeat frequently.  The rest of our daily experiences rarely become long-lasting memories.  In fact, we retain most information for only a few minutes or hours before it fades away.

Scientists have recently discovered that when a memory is recalled, it becomes sensitive to disruption and become fragile after recall for a limited time.

An event’s biological relevance makes it important.  We remember painful, aversive events so that we can avoid repeating them; we remember happy, advantageous experiences because they represent our best biological fit (such as the best sources of food and sex).  In other words, emotional events, whether god or bad, stay with us: the stronger the emotion, the longer lasting the memory.

“More than 100 years of work in both humans and animals have shown that a newly formed explicit memory remains in a fragile state for quite some time.  Indeed, if pharmacological or functional interferences of brain activity occur during or immediately after an event as a consequence of, for example, stroke, physical trauma, or behavioral interferences, a long-term memory of the event will not form.  A typical example is a car accident.  A person will not remember the details about what happened just before and around the time of the accident.  The fragility of memory is greater right after the event, or learning phase.  As time passes, the memory becomes more resistant to disruption.

The process that mediates this time-dependent stabilization of memory is known as consolidation.  The duration and anatomy of the consolidation process still is not fully understood.  Clinical studies of people have revealed that memory consolidation takes weeks to years and occurs while the information is proceeded by the part of the brain known as the medial temporal lobe.  However, once a memory has been consolidated, information storage seems to involve brain regions other than the temporal lobe, particularly cortical areas.

Research has shown that memory consolidation requires the activation of molecular and cellular pathways.  For decades, scientists believe that consolidation of explicit memories occurred through a single process of stabilization.  They hypothesized that the process of memory consolidation involves molecular changes during the first 24 hours, significantly engages the hippocampus and related brain areas for a few weeks to months, and later involves different brain regions in the cortex, at which point memory was considered consolidated and insensitive to disruption.  However, recent studies have challenged this hypothesis.

About 10 years ago, investigators revisited discoveries made in the 1960s.  They found that memories that were one day old or older, and thus resistant to biochemical interferences, became sensitive again to interferences if and only if they were recalled.  In short, recalling a memory makes it liable, or modifiable, for a few hours.  During this time the memory restabilizes in much the same way a new memory consolidates after learning.  Thus, a day after recall a memory is again stable and resistant to disruption.  This post-recall process of restabilization has been termed reconsolidation.”

Paraphrased and quoted from “Long-term Memories: The Good, the Bad, and the Ugly” by Cristina M. Alberini, Ph. D. Cerebrum: The Dana Forum on Brain Science, October 2010




In case you get bored with the lazy days of summer and want to get a jump preparing for the coming school year, I added to Stuff4Educators a section called How to Study Better based on research from Harvard Medical School that highlights four science-backed ways towards better learning (Hint: drop the highlighter). Additionally, I posted a YouTube video under exercise from the Dana Foundation that won the Northwest Emmy award called Exercise and the Brain that explores the benefits of exercise on the brain and learning. Finally, some books that I have read this past year and found to be stimulating are listed.