Memory

Mini Review

• Sensation delivers raw signals, attention selects a few of them, and perception turns those few into a meaningful picture.
• All of that happens in the moment the signals arrive.

The Memory Level of the Processing Pyramid

• Perception built the picture. Memory is what keeps it.

The Three Stages of Memory

• Encoding: The process of converting perceived information into a form that can be stored in memory.
• Storage: The process of holding encoded information in memory until it is needed.
• Retrieval: The process of finding stored information and bringing it back into awareness.
• The three stages depend on each other. Nothing can be retrieved that was not stored, and nothing can be stored that was not encoded.
• Encoding and storage happen in two different memory systems.

The Two Memory Systems

• Information is held briefly in one system, and moved into and pulled back out of the other.

Working Memory

• Working memory: The memory system that holds and works on a small amount of information for the few seconds it is in use.
• Whatever you are thinking about right now is in working memory. It is an activity, not a storage place.
• Connections to what we have covered:
  • The neural pathways that are active right now are the contents of working memory.
  • Whatever attention selects is what enters it.
• Working memory holds very little at once.

The Capacity of Working Memory and Chunking

• Working memory holds about four units of information at a time. The older estimate was seven, plus or minus two.
• Each unit can hold a lot, depending on how the person organizes it. The units are called chunks.
  • Ex: 4060112250704 is 13 digits, which is more than working memory can hold.
  • Ex: 40601 (Frankfort’s zip code), 1225 (Christmas), 0704 (the Fourth of July) is the same 13 digits as three chunks.
• Chunking: The process of grouping separate pieces of information into larger, meaningful units so that more fits in working memory.
• Chunking is a link to our Limited Capacity theme, because it works around the limit instead of raising it.
• Information that has to outlast the next few seconds has to move somewhere else.

Long-Term Memory

• Long-term memory: The memory system that stores everything a person knows.
• Almost everything you know is in it, and almost none of that is in working memory at this moment.

Working Memory Compared With Long-Term Memory

Poll 1

• Twelve words will appear one at a time. Read each one and try to remember it.
• Do not write anything down.
• When the list ends, type every word you remember into the poll.

Poll: Which Words Do You Remember?

Poll Results

Poll 2

• Twelve new words, same rules.
• This time, when the list ends, you will do one more thing before the poll.

Poll: Which Words Do You Remember?

Poll Results

The Free Recall Study

• What you just did is a version of the study that first showed the pattern.
• The free recall study (1966): People heard a list of 15 words, one at a time, and then wrote down as many as they could in any order. Some recalled right away, and some first spent 30 seconds counting backward.
  • Finding: With immediate recall, the first few words and the last few words were remembered best. After the 30-second counting task, the last few words lost their advantage and the first few kept theirs.
• Primacy effect: Better memory for the first few items in a list than for the items in the middle.
• Recency effect: Better memory for the last few items in a list than for the items in the middle.
• The next figure shows both patterns.

Recall by Position in the List

• The two ends of the list come from two different systems.

Why the Two Effects Show Two Systems

• The first words were rehearsed while the list went on, so they reached long-term memory. Counting backward for 30 seconds did not remove them.
• The last words were still in working memory when recall began. Counting backward for 30 seconds filled working memory with numbers, so they were gone.
• A delay that erases one effect but not the other means the two effects were held in different places.
• The first words got into long-term memory because they were repeated, but repeating is the weakest way to get something into long-term memory.

Poll 3

• Words will appear one at a time with a yes-or-no question about each one.
• Answer each question in your head.

Poll: Which Words Do You Remember?

Poll Results

The Depth of Processing Study

• Why is it easier to remember the words you tried to fit in a sentence?
• The depth of processing study (1975): People saw words one at a time and answered one question about each: whether it was in capital letters, whether it rhymed with another word, or whether it fit into a sentence. Later they were given a surprise memory test.
  • Finding: Words judged for sentence fit were remembered far better than words judged for rhyme, and words judged for rhyme better than words judged for capital letters. Nobody had been told to memorize anything.

Shallow Processing

• Shallow processing: Paying attention to the surface features of information, such as how a word looks or sounds.
  • Ex: Noticing that a word is printed in capital letters.
  • Ex: Saying a phone number over and over until you can type it in.
• Repeating something many times is shallow processing. It keeps information in working memory, but it does not by itself move it into long-term memory, at least beyond a few minutes. What does?

Deep Processing

• Deep processing: Paying attention to the meaning of information and how it relates to other things you know.
  • Ex: Deciding whether a word makes sense in a given sentence.
  • Ex: Rewording one of our four core themes and coming up with your own example of it.

Deep Processing Builds Connections

• Thinking about meaning creates connections between the new information and what is already in long-term memory.
• Each connection is a path that retrieval can follow later, so information with more connections is easier to find.
• Paying attention to meaning builds those paths whether or not the person is trying to remember, which is why the surprise test still showed the effect.
• Every study strategy you use processes the material at one depth or the other.