How Do We Remember? A Neuroscience Explanation

I just found a great tech­ni­cal descrip­tion ‑see below- of how we remem­ber in the Brain Back­grounders at The Soci­ety for Neu­ro­science website.

If you are look­ing for a less tech­ni­cal expla­na­tion, you will enjoy read­ing instead:

- Improve Mem­o­ry with Sleep, Prac­tice, and Testing

- Try Think­ing With­out Work­ing Memory

- New Neu­rons: Good News, Bad News

At first the activ­i­ty of var­i­ous chem­i­cals pro­vides knowl­edge with a tem­po­rary occu­pan­cy in the brain, last­ing for a few min­utes. The mem­o­ry is in its “short-term” phase. This fresh infor­ma­tion is evict­ed and for­got­ten unless essen­tial mol­e­cules and genes are activated.

Many researchers believe that the process of trans­form­ing a short-term mem­o­ry into a long-term mem­o­ry begins when brain cells receive sig­nals that induce reac­tions involv­ing the mol­e­cule, pro­tein kinase A. This, in turn, sets off anoth­er mol­e­cule in the cell known as cyclic AMP-response ele­ment bind­ing pro­tein (CREB). CREB acti­vates genes, which are seg­ments of the cel­l’s deoxyri­bonu­cle­ic acid (DNA). Genes hold sequences of cod­ing mol­e­cules that pro­vide the bio­log­i­cal instruc­tions for pro­duc­ing pro­teins. The devel­op­ment and func­tion of the body and brain is direct­ed by many dif­fer­ent pro­teins. The genes acti­vat­ed by CREB lead to the pro­duc­tion of spe­cial pro­teins that change the struc­ture and activ­i­ty of nerve cells. These reac­tions fas­ten infor­ma­tion for days, weeks or longer.

The core mol­e­c­u­lar switch appears to be involved in secur­ing the mem­o­ries of facts and events, known as explic­it mem­o­ries, as well as implic­it mem­o­ries. Implic­it mem­o­ries remind you how to do some­thing. They involve motor skills and per­cep­tu­al strate­gies. The answers to the his­to­ry test ques­tions rely on explic­it mem­o­ries. Implic­it mem­o­ries remind you how to actu­al­ly write the responses.

While at least some of the chem­i­cal reac­tions need­ed to con­vert a short-term mem­o­ry into a long-term mem­o­ry appear to be the same, the mem­o­ry pro­cess­ing occurs in dif­fer­ent brain areas. Explic­it mem­o­ries require the brain regions with­in the tem­po­ral lobe of the cere­bral cor­tex includ­ing the hip­pocam­pus. Implic­it mem­o­ries are primed in the spe­cif­ic sen­so­ry and motor sys­tems that are recruit­ed for what­ev­er the par­tic­u­lar task is.

Think­ing of all those fresh mem­o­ries being “evict­ed and for­got­ten” unless a whole chain of mol­e­c­u­lar events takes place makes me won­der if we should stop wor­ry­ing about why we for­get and instead won­der why we ever remember!