Models of Memory

Three-Box/Information-Processing Model

• The principal model of memory is the three-box model, also called the information-processing model.

• This model proposes the three stages that information passes through before it is stored.

• External events are first processed by our sensory memory.

• Then some information is encoded into our short-term (or working) memory.

• Some of that information is then encoded into long-term memory.

Sensory Memory

• The first stop for external events is sensory memory.

  • It is a split-second holding tank for incoming sensory information.

  • All the information your senses are processing right now is held in sensory memory for a very short period of time (less than a second).

• Researcher George Sperling demonstrated this in a series of experiments in which he flashed a grid of nine letters, three rows and three columns, to participants for 1/20th of a second.

• Iconic memory- a split-second perfect photograph of a scene.

• Echoic memory- an equally perfect brief (3–4 second) memory for sounds.

• Most of the information in sensory memory is not encoded, however.

• Only some of it is encoded, or stored, in short-term memory.

• Selective attention - Sometimes selective attention is not as controlled.

  • You have probably had the experience of speaking with one person at a party but then hearing someone say your name across the room.

Short-Term/Working Memory

• Short-term memory is also called working memory because these are memories we are currently working with and are aware of in our consciousness.

  • Everything you are thinking at the current moment is held in your short-term or working memory.

  • Short-term memories are also temporary.

• Another way to retain information in short-term memory is to rehearse (or repeat) it.

  • When you look up a phone number and repeat it to yourself on the way to the phone, you are rehearsing that information.

Long-Term Memory

• Long-term memory is our permanent storage.

  • As far as we know, the capacity of long-term memory is unlimited.

• Memories can also be implicit or explicit.

• Explicit memories (also called declarative memories) are what we usually think of first.

• Implicit memories (also called nondeclarative memories) are unintentional memories that we might not even realize we have.

• Memory researchers are particularly interested in individuals who demonstrate eidetic, or photographic, memory.

• Psychologist Alexander Luria studied a patient with eidetic memory who could repeat a list of 70 letters or digits.

Levels of Processing Model

• An alternate way to think about memory is the levels of processing model.

• This theory explains why we remember what we do by examining how deeply the memory was processed or thought about.

• Memories are neither short- nor long-term.

  • They are deeply (or elaboratively) processed or shallowly (or maintenance) processed.

• If you simply repeat a fact to yourself several times and then write it on your test as quickly as you can, you have only shallowly processed that fact and you will forget it quickly.

Retrieval

• Recognition is the process of matching a current event or fact with one already in memory (e.g. “Have I smelled this smell before?”).

• Recall is retrieving a memory with an external cue (e.g. “What does my Aunt Beki’s perfume smell like?”).

• One factor is the order in which the information is presented.

• In some of the first psychological experiments, Hermann Ebbinghaus (1850–1909) established that the order of items in a list is related to whether or not we will recall them.

• The primacy effect predicts that we are more likely to recall items presented at the beginning of a list.

• The recency effect is demonstrated by our ability to recall the items at the end of a list.

• Together the primacy effect and recency effect demonstrate the serial position effect (also called serial position curve).

  • This effect is seen when recall of a list is affected by the order of items in a list.

• This temporary inability to remember information is sometimes called the tip-of-the-tongue phenomenon.

• One theory that explains why this might work is the semantic network theory.

  • This theory states that our brain might form new memories by connecting their meaning and context with meanings already in memory.

• These flashbulb memories are powerful because the importance of the event caused us to encode the context surrounding the event.

• Studies consistently demonstrate the power of mood-congruent memory or the greater likelihood of recalling an item when our mood matched the mood we were in when the event happened.

• State-dependent memory refers to the phenomenon of recalling events encoded while in particular states of consciousness.

Constructive Memory

• A constructed (or reconstructed) memory can report false details of a real event or might even be a recollection of an event that never occurred.

• Studies show that leading questions can easily influence us to recall false details, and questioners can create an entirely new memory by repeatedly asking insistent questions.

Forgetting

• Many studies show an important relearning effect.

• If you have to memorize the capitals again, it will take you less time than it did the first time you studied them.

• Another factor that causes forgetting is interference.

• Sometimes other information in your memory competes with what you are trying to recall.

• Interference can occur through two processes:

  • Retroactive interference : Learning new information interferes with the recall of older information.

    • If you study your psychology at 3:00 and your sociology at 6:00, you might have trouble recalling the psychology information on a test the next day.

  • Proactive interference: Older information learned previously interferes with the recall of information learned more recently.

    • If a researcher reads you a list of items in a certain order, then rereads them differently and asks you to list them in the new order, the old list proactively interferes with recall of the new list.

How Memories Are Physically Stored in the Brain

• Individuals with damage to the hippocampus might have anterograde amnesia (they cannot encode new memories), but they can recall events already in memory.

  • They can learn new skills, although they will not remember learning them.

• At the neurological level, researchers focus on a process called long-term ­potentiation.

• Studies show that neurons can strengthen connections between each other.

Language

• Language is intimately connected to cognition.

• Some psychologists investigate how language works and how we acquire it in an attempt to better understand how we think and behave.

Elements of Language

• All languages can be described with phonemes and morphemes.

• Phonemes are the smallest units of sound used in a language.

• A morpheme is the smallest unit of meaningful sound.

Language Acquisition

• Many psychologists are particularly interested in how we learn language.

• Often, developmental psychologists are curious about how our language learning reflects or predicts our cognitive development.

• These studies show that while babies are learning very different languages, they progress through the same basic stages in order to master the language.

• During which babies speak in single words (holophrases) is sometimes called the holophrastic stage or one-word stage.

• The next language acquisition stage occurs at around 18 months and is called telegraphic speech or two-word stage.

• Toddlers will combine the words they can say into simple commands.

• This misapplication of grammar rules is called overgeneralization or overregularization.

• Researcher Noam Chomsky theorized that humans are born with a language acquisition device, the ability to learn a language rapidly as children (this is also called the nativist theory of language acquisition).

Language and Cognition

• Psychologist Benjamin Whorf theorized that the language we use might control, and in some ways limit, our thinking.

• This theory is called the linguistic relativity hypothesis.

Thinking and Creativity

Describing Thought

• Descriptions are thoughts, so we are attempting to describe thought using thought itself.

• Concepts are similar to the schemata mentioned previously.

• Another type of thought, images; are the mental pictures we create in our minds of the outside world.

• Images can be visual, such as imagining what your cat looks like.

Problem Solving

• Many researchers try to study thought by examining the results of thinking.

• Researchers can ask participants to solve problems and then investigate how the solutions were reached.

Algorithms

• An algorithm is a rule that guarantees the right solution by using a formula or other foolproof method.

• Sometimes algorithms are impractical, so a shortcut is needed to solve certain problems.

Heuristics

• A heuristic is a rule of thumb—a rule that is generally, but not always, true that we can use to make a judgment in a situation.

• Availability heuristic - Judging a situation based on examples of similar situations that come to mind initially.

  • This heuristic might lead to incorrect conclusions due to variability in personal experience.

• Representativeness heuristic - Judging a situation based on how similar the aspects are to prototypes the person holds in his or her mind.

• Overconfidence is our tendency to overestimate how accurate our judgments are.

• Belief bias occurs when we make illogical conclusions in order to confirm our preexisting beliefs.

• Belief perseverance refers to our tendency to maintain a belief even after the evidence we used to form the belief is contradicted.

• Another obstacle to successful problem solving is confirmation bias.

  • Many studies show that we tend to look for evidence that confirms our beliefs and ignore evidence that contradicts what we think is true.

• Framing refers to the way a problem is presented.

Creativity

• Some researchers are investigating the distinctions between convergent thinking, thinking pointed toward one solution, and divergent thinking, thinking that searches for multiple possible answers to a question.

• Divergent thinking is more closely associated with creativity.

• Creative activities usually involve thinking of new ways to use what we are all familiar with or new ways to express emotions or ideas we share.