Memory Chapter 6
What is Memory? • Memory is the system by which we retain information and bring it to mind. • Without memory, experience would leave no mark on our behavior; we would be unable to retain the information and skills we acquire through experience.
Human Memory as an Information Processing System • 3 basic processes of human memory; • Encoding • Storage • Retrieval • These processes allow us to take information, encode it in a form that can be stored in memory, and later retrieve it when it is needed.
Three Basic Processes of Memory Storage Encoding Retrieval Converting information into a form usable in memory Bringing to mind information stored in memory Retaining Information in memory
Memory Encoding: Taking in information • Information about the outside world comes to us through our senses, but for this information to enter memory, it must undergo a process of memory encoding, or conversion into a form we can store in memory. • Ways we encode information; • Acoustically (coded by sound) • Visually (coded by forming a mental picture) • Semantically (coded by meaning)
Memory Storage: Retaining Information in Memory • Memory storage is the process of retaining information in memory. • Not all information becomes an enduring or long-term memory. • Some information is retained for only a fraction of a second.
Memory Retrieval: Accessing Stored Information • Memory retrieval is the process of accessing stored information to make it available to consciousness. • Retrieving long-held information is one of the marvels of the human brain. • Some memories seem to be retrieved effortlessly, others depend on the availability of retrieval cues, cues associated with the original learning, to jog them into awareness.
Memory Stages • Some memories are fleeting; others are more enduring. • The three-stage model of memory proposes three distinct stages of memory that vary with the length of time information is stored; • Sensory memory • Short-term memory • Long-term memory
Sensory Memory: Getting to know what’s out there • Sensory memory is a storage system that holds sensory information in memory for a very short time. • Stimuli that you bring in constantly strike your sensory receptors, forming impressions that are briefly held in sensory memory in a kind of temporary storage device called sensory register.
Sensory Memory: Getting to know what’s out there • This information lasts in memory for perhaps a fraction of a second to as long as 3-4 seconds. • The sensory impression disappears and is replaced by the next one. • Iconic memory- A sensory store for holding mental representation of a visual image for a fraction of a second. • A visual held in iconic memory is so clear and accurate that people can report exact details of the image.
Sensory Memory: Getting to know what’s out there • Some people can recall a visual image they have previously seen as accurately as if they are still looking at it. This is known as eidetic memory • This is also known as photographic memory (eidetic comes from the Greekeidos, meaning “image”). • Eidetic imagery is rare in adults, but it occurs in about 5% of young children.
Sensory Memory: Getting to know what’s out there • Echoic memory is a sensory store for holding a mental representation of a sound for a few seconds after it registers in the ears. • Although sounds held in echoic memory fade quickly, they last about two or three seconds longer than visual images.
Short-Term, or Working, Memory: the mind’s Blackboard • Many sensory impressions don’t just fade away into oblivion; they are transferred into short-term memory for further processing. • Short-term memory is the memory subsystem that allows for retention and processing of newly acquired information for a maximum of about 30 seconds.
Short-Term, or Working, Memory: the mind’s Blackboard • Short-term memory relies on both acoustic and visual coding, but mostly on acoustic (ex. Repeating a phone number to yourself until you dial it). • In the 1950s psychologist George Miller did studies to determine the storage capacity if short-term memory. • Professor Miller determined that people can retain 7 items (plus or minus 2), referred to as the “Magic 7”.
Row 1 6293
Row 2 73932
Row 3 835405
Row 4 3820961
Row 5 18294624
Row 6 9284619384
Row 7 1992199319941995
Short-Term, or Working, Memory: the mind’s Blackboard • Did you do better remembering the 7th row than the 5th or 6th? • If you did, it is because of chunking- the process of breaking a large amount of information into smaller chunks to make it easier to recall. • Children learn the alphabet by chunking a series if letters (that’s why they often say the letters lmnop as if they are one word)
Long-Term Memory: preserving the past • Long-term memory is a storage system that allows you to retain information for periods of time beyond the capacity of short-term memory. • Some info can remain for days or weeks, whereas other info can last a lifetime. • Short-term memory storage is limited, but long-term storage is virtually limitless.
Long-Term Memory: preserving the past • Consolidation is the process by which the brain converts unstable, fresh memories into stable, long-term memories. • The first 24 hours after information is acquired are critical for consolidation to occur. • REM sleep plays an important role in consolidating daily experiences, so if you have a test the next day, make sure you get a good night’s sleep.
Declarative memory: “knowing That” • Declarative Memory: Memory of facts and personal info that requires a conscious effort to bring to mind. • Ex. There are 50 states, what street we live on. • Semantic Memory: Memory of facts. • Ex. Which film won Best Picture last year, who wrote Grapes of Wrath. • Episodic Memory: Memory of personal experiences that constitute the story of your life. • Ex. What you had for dinner last night, when you fell out of a tree when you were 10.
Flashbulb Memory: What were you doing when…? • Extremely stressful or emotionally arousing personal or historical events may leave vivid, lasting, and highly detailed memories called flashbulb memories. • Flashbulb memories are enduring memories of emotionally charged events that seem permanently seared into the brain. • Some flashbulb memories are accurate, but others are prone to the kinds of distortion we see in other forms of long-term memory.
Eyewitness testimony: :What did you see on the day in question?” • In reaching a verdict, juries give considerable weight to eyewitness testimony. Yet memory researchers find that eyewitness testimony can be as flawed and strewn with error as other forms of memory. • Psychologist Elizabeth Loftus describes how a misinformation effect may lead to distortions in eyewitness testimony from when the event happened to when the events are recalled (in court).
Eyewitness testimony: :What did you see on the day in question?” • The accuracy of eyewitness testimony involves the following factors. • Ease of recall- People who take longer to answer questions are less likely to be accurate in their recall. • Degree of Confidence- People who say with certainty, “That’s the person who did it, “ may not be any more accurate than those who admit they could be mistaken.
Eyewitness testimony: :What did you see on the day in question?” • General knowledge about a subject- People who know more about a subject are more likely than those who know less about the subject to be reliable witnesses. • Racial identification- People are generally better able to recognize faces of people of their own race than the face of people of other races.
Eyewitness testimony: :What did you see on the day in question?” • Types of questions- Leading or suggestive questions by investigators can result in the misidentification of perpetrators, whereas open-ended questions, tend to increase the accuracy of eyewitness testimony. • Facial characteristics- Faces with distinctive features are much more likely to be accurately recognized than nondistinctive faces.