Unit 3: How People Remember

Short term memory, or working memory, is quick information we try to store for short-term use. In order to remember the information we must keep our attention focused on it. Working memory activates the prefrontal cortex of the brain. Stress will have an adverse effect on to the working memory.

The magic number is 4 - that is four items that people can remember, or store, in the working memory if not distracted. Grouping things in "chunks" helps us remember. Examples include phone numbers, 205-546-5128, or social security numbers, 121-00-9988. These groupings are separated into three groups or chunks and we can remember them as three items. If these numbers, or items, are used repetitively or  related to something we know, like a family member, than the information moves into long-term memory. Another example of remembering things in groups is "schema" - the head can include the whole schema of eyes, nose, lips, hair for example.

Memories aren't stored in our brains like movies or files on a computer. Instead are nerve pathways that fire anew on each retrieval. The negative effect of memories is that they can change each time they're retrieved. This happens because of events that take place afterwards effects the original movie, particularly if its a related event or person. We'll also fill in gaps with "made-up" information, this is called reconstructive memory.

An accidental study with rats in a maze ended up in additional research showing that their brains were just as active in their sleep as they were while awake. The study implies that humans have the same condition and that our brains are consolidating new memories and creating new associations - basically deciding what to remember and what to forget. This doesn't always work in our favor, but it is what humans have inherited for survival to evolution. 

Forgetting Curve - we quickly forget information not stored in long-term memory. Our brains keep us alive by not remembering everything, because too much sensory input would be overwhelming to us.

Infographic on Memory Retention and the Forgetting Curve

Other Terms
Recall Task: "involves presenting a subject with material that is to be memorized. Once the material is removed the subject is to immediately demonstrate everything that they remember from the material" [Cognitive Atlas].
Recognition Task: easier because of context; "Subjects view a string of letters. After a delay, a probe letter is presented and subjects indicate if the presented letter was in the previously viewed group" [Cognitive Atlas] .
Recency Effect: recalling most recent information; "If you hear a long list of words, it is more likely that you will remember the words you heard last (at the end of the list) than words that occurred in the middle" [Alley Dog].
Suffix Effect: "the weakening of the recency effect in the case that an item is appended to the list that the subject is not required to recall" [Morton, Crowder & Prussin, 1971.