Memory

1. Memory Psychology: A Concise Introduction2nd Edition Richard Griggs Chapter 5 Prepared byJ. W. Taylor V

2. The Journey… • Three-Stage Model of Memory • Encoding Information into Memory • Retrieving Information from Memory

3. Three-Stage Model of Memory Sensory Memory Short-Term Memory Long-Term Memory

4. The Three-Stage Model • Has guided research in memory since the late 1960s • Views memory as composed of three relatively distinct stages Sensory Short-Term Long-Term

5. The Three-Stage Model

6. Sensory Memory • Consists of a set of five registers (temporary storage places, one from each sense) for incoming sensory information from the physical environment until we attend to it, interpret it, and it proceeds to the next stage of memory (short-term memory)

7. Iconic Memory • Is an exact copy of visual information • Less than a second in duration • Very large capacity • Consider the example of a cartoon movie, which is nothing more than a series of still drawings flashed in rapid succession • Iconic memory allows us to perceive motion in the drawings

8. Testing Iconic Memory • The temporal integration procedureinvolves giving two random meaningless dot patterns sequentially at the same visual location with a brief time delay between the two presentations • When the two patterns are integrated, a meaningful pattern is produced

9. An Example of the Temporal Integration Procedure

10. Testing Iconic Memory • For a meaningful pattern to be perceived, the two patterns must be integrated somewhere in the memory system • However, if the time delay between the two presentations is greater than one second, no meaningful pattern can be perceived because the image from the first pattern has faded from iconic memory

11. Testing Iconic Memory • Sperling’s full- and partial-report procedures present participants with a different 3 x 3 matrix of unrelated consonants (a total of 9) for 50 ms across numerous experimental trials • Here is an example: L Z Q R B P S K N

12. Testing Iconic Memory • In the full-report procedureparticipants had to report the entire matrix • Participants said they sensed the entire matrix but that it had faded from memory before they could report all 9 letters

13. Testing Iconic Memory • In the partial-report procedure, the participants had to report only one row of the matrix, a row indicated by an auditory cue on each trial • When the auditory cue was given immediately after the brief presentation of the letter matrix, participants recalled the indicated row 100% of the time • When there was a one second delay between presentation of the matrix and the auditory cue, participants’ recall of the cued row worsened

14. Short-Term Memory • Is the memory stage in which the recognized informa-tion from sensory memory enters consciousness • It is where you are doing your present conscious cognitive processing • Serves as a place to rehearse information so it can be transferred to long-term memory and as a place to bring information from long-term memory when asked to recall it • Must concentrate on information in short-term memory or it will be lost in 30 seconds

15. Capacity of Short-Term Memory • The memory spantask tests for the capacity of short-term memory by giving a series of items one at a time • The person has to remember the items in the order in which they were presented • Memory span is the average number of items you can remember across a series of memory span trials • Humans have a memory span of 7+/- 2 (5 to 9) chunks of information • A chunkis a meaningful unit of information • Experts in a given domain tend to have larger chunks for information in their area of expertise

16. Duration of Short-Term Memory • Measured using the distractor task, in which people are given a small amount of information (e.g., three unrelated consonants such as CWZ) • Then the participant is immediately distracted from concentrating on the information for a brief time period (by counting backwards aloud by 3’s), and then asked to recall the information • To keep information in short-term memory, we use maintenance rehearsal (i.e., repeating information in short-term memory to keep in from fading from short-term memory)

17. Results for the Short-Term Memory Distractor Task

18. Long-Term Memory Allows storage of information for a long period of time (perhaps permanently) and its capacity is essentially unlimited

19. Types of Long-Term Memory • Explicit memory(also called declarative memory) is long-term memory for factual knowledge and personal experiences and requires conscious recall • Two types of explicit memories: • Semantic memoriesare memories for factual knowledge that is true of everyone (e.g., the current President of the United States) • Episodic memories are memories for personal life experiences (e.g., your senior prom night)

20. Types of Long-Term Memory • Implicit memory(also called non-declarative memory) is long-term memory that influences our behavior, but does not require conscious awareness or declarative statements (e.g., for most adults, driving a car; walking) • Some implicit memories are procedural memoriesbecause they have a physical procedural aspect to them • For a tennis expert, such as Serena Williams, the movements to play the game are implicit, procedural memories, whereas for the average person, such movements require conscious recall, and are more semantic memories • Other implicit memories have become automatic responses to certain stimuli (e.g., feeling tense when police car lights are flashing behind us)

21. Types of Long-Term Memory

22. Amnesia, the Loss of Long-Term Memories • Amnesicsare people with severe memory deficits following brain surgery or injury • H. M. had his hippocampus and surrounding temporal lobe area removed at age 27 (to reduce epileptic seizures) • Before the operation, both his short- and long-term memories were normal • After the operation, he didn’t seem to be able to store any new information in long-term memory • H.M. suffered from anterograde amnesia – the inability to form long-term memories for events following brain surgery or trauma • By contrast,retrograde amnesiais the inability to remember events before, especially just before, the surgery or trauma

23. Infantile Amnesia • The cerebellum seems to be important for formation of implicit memories, whereas the hippocampus seems to be important for formation of explicit memories • Because the hippocampus does not fully develop until about the age of 3, this explains why we cannot remember as adults events that occurred prior to this age (i.e., infantile/ child amnesia)

24. Evidence for the Short-Termvs. Long-Term Distinction • H. M.’s short-term memory did not suffer any substantial damage after the operation • The free recall taskis an experimental procedure in which participants are given a list of words one at a time, then asked to recall them in any order they wish • Compared with the middle of such lists, the recall of the items at the start of the list is superior (theprimacy effect) • Compared with the middle of such lists, the recall of the items at the end of the list is superior (therecency effect)

25. Serial Position Effects for the Free Recall Task

26. Evidence for the Short-Termvs. Long-Term Distinction • The recency effect is caused by recall from short-term memory, whereas the primacy effect is the result of superior recall from long-term memory of the first few words in the list • The first few words enter an empty long-term memory and get proportionately more attention than the words in the middle of the list and can thus be transferred into long-term memory • The last few words are still in short-term memory at the time of recall • If recall is delayed by having participants count rapidly backward by 3’s for 30 seconds, the recency effect is eliminated, but the primacy effect remains • To eliminate the primacy effect, simply rehearse each of the items on the list equally

27. Encoding Information into Memory How We Encode Information How to Improve Encoding

28. Memory System Processes EncodingThe process of transferring information from one memory stage to the next Storage The process of maintaining information in a particular stage Retrieval The process of bringing stored information from long-term memory to the conscious level in short-term memory

29. How We Encode Information • Automatic processingis processing that occurs subconsciously and does not require attention • Effortful processingis processing that occurs consciously and requires attention • For a particular type of processing, much practice is needed

30. Levels-of-Processing Theory • Describes what types of encoding lead to better retrieval • Three levels of processing • Physical: How information appears • Acoustic: How the information sounds • Semantic: What the information means • Long-term memory is best for information encoded semantically, next best for information encoded acoustically, and worst of information encoded physically

31. Elaborative Rehearsal • Rehearsing information by relating new information to information already in long-term memory • Contrasts with maintenance rehearsal (i.e., the repetitive cycling of information in short-term memory) • Elaborative rehearsal provides more retrieval cues to facilitate retrieval • A good way to elaborate on new material is to relate the material to yourself • The self-reference effect says it is easier to remember information that you have related to yourself because such connections provide more retrieval cues and lend more meaning to the new information

32. Environmental Effects on Encoding • Encoding specificity principle proposed that the cues present during encoding serve as the best cues for retrieval • This is why the various concepts and examples that you relate to a new concept during elaborative rehearsal help you remember the concept • State-dependent memory is memory that depends upon the relationship of one’s physiological state at the time of encoding and at the time of retrieval

33. Environmental Effects on Encoding • Mood-dependent memory effects attest to the fact that memory is better when a person’s mood is the same during encoding and retrieval • For example, if you are happy during encoding information, it is easier to retrieve that information if you are happy at the time of retrieval • Mood-congruence effectis the fact that memory is better for experiences that are congruent with a person’s current mood • For example, when we are sad it is easier to retrieve negative events in our lives

34. How to Improve Encoding • Mnemonics are memory aids that require elaborative rehearsal • In the method of loci, the sequential pieces of information to be remembered are first associated with sequential locations in a very familiar room or location • When retrieving the information, you merely mentally go around the room (or location) and retrieve the item stored at each sequential location; uses elaborative mental imagery • In the peg-word system, you visually associate the items to be remembered in a jingle that you first memorize

35. The Peg-Word Method

36. The Peg-Word Method

37. The Peg-Word Method

38. Other Tips for Improving Encoding • Thespacing effect(or distributed study effect) contends that your memory will improve if you study for an exam over an extended time interval rather than just a few days before the exam • Overlearning is studying material past the point of initial learning, and has been demonstrated to aid in retrieval of that information

39. Retrieving Information from Memory How to Measure Retrieval Why We Forget The Reconstructive Nature of Retrieval

40. How to Measure Retrieval • Recallis a measure of retrieval that requires the reproduction of the information with essentially no retrieval cues • Recognitionis a measure of retrieval that only requires the identification of the information in the presence of retrieval cues • Relearning, also called the savings method, is a measure of the amount of time saved when learning the information for a second time

41. An Early Study • Ebbinhaus conducted the first experimental studies on human memory more than 100 years ago using the relearning method. • He would study a list of nonsense syllables until he could correctly recite the complete list without any hesitations. He then put the list aside and waited some period of time and then relearned the list to the same criterion. • To get a measure of learning, he computed a savings score – the reduction in the number of trials it took him to reach criterion. • Result? The “forgetting curve” reveals that most forgetting occurs in the first two days after learning material.

42. Forgetting Curve for Long-Term Memory

43. Why We Forget • Encoding failure theory says that sometimes forgetting is not really forgetting, but rather that the information never entered long-term memory in the first place • Storage decay theory suggests that forgetting occurs because of a problem in the storage of the information • The biological trace of the memory gradually decays over time and the periodic usage of the information will help to maintain it in storage

44. An Example of Encoding Failure

45. Why We Forget • Cue-dependent theory says we forget because the cues necessary for retrieval are not available • The information is in memory, but we cannot access it • This theory is analogous to knowing a book is in the library but you cannot access it because the library lacks call numbers • Interference theory proposes that other similar information interferes and makes the forgotten information inaccessible

46. Types of Interference • Proactive interferenceoccurs when information you already know makes it hard to retrieve newly learned information • Retroactive interferenceoccurs when information you just learned makes it hard to retrieve old information

47. Types of Interference

48. Types of Interference • Think about changing phone numbers after having a certain number for many years. When asked for your new phone number, remembering the old one interferes with retrieving the new one. • This is proactive interference • Now think about being at a party with many people you don’t know. You meet someone whom you want to talk to later, but after meeting her, you are introduced to many more people. Now, you cannot remember her name. • This is retroactive interference

49. The Reconstructive Nature of Retrieval • When reading a newspaper article, for instance, we usually code the gist or main theme of the story, along with some of the some of the story’s highlights • Then, when we retrieve the information from our memory, we re-construct a memory of the story using the theme and highlights • Retrieval re-construction is guided by schemas– organized frameworks of knowledge about people, objects, and events that tell us what normally happens in a given situation • They allow us to encode and retrieve information more efficiently

50. The Reconstructive Nature of Retrieval • Schemas, however, can lead us to “misremember” information so that it is more consistent with our schemas • Frederick Bartlett (1932) had people read unusual stories and subsequently recall details from the stories • When the participants recalled the stories, they made them more consist with their schemas about the world