Sensory Memory, Short-Term Memory & Working Memory

Transcription

1 Sensory, Short-Term & Working Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/17/2018: Lecture 04-2 Note: This Powerpoint presentation may contain macros that I wrote to help me create the slides. The macros aren t needed to view the slides. You can disable or delete the macros without any change to the presentation.

2 To Be Discussed Later UW: Psych 355, Miyamoto, Spr '18 Systems 2

3 Psych 355, Miyamoto, Spr '18 3 What Are Systems? Overview of Systems: Sensory This lecture Short-Term / Working (STM / WM) Long-Term (LTM) Later WM LTM Multiple Components Multiple Components What function do these memory systems serve?

4 What Are Systems? systems retain perceptions, images, motor patterns, experiences, ideas, thoughts, and intentions that were present at one time but are no longer present. Major Functions of Systems Store information over a period of time (seconds; minutes; hours; years) Pass information between different memory systems Encode information (put information into a long-term storage) Retrieve memories or previous learning based on relevance or usefulness in current processing. Especially important: Retrieval of information that is relevant to a current activity. Manipulate information in working memory Modal Model of UW Psych 355, Miyamoto, Spr '18 4

5 The Modal Model (Atkinson & Shiffrin, 1968) Goldstein Figure 5.2 Control Processes, e.g., rehearsal Input Sensory Short-Term Long-Term Output: Speech & Actions The Modal Model of (Atkinson & Shiffrin, 1968) Sensory brief storage of current perceptual inputs. STM short-term storage of current mental activity STM or Working (WM) has multiple components LTM long-term storage of experiences, thoughts, facts LTM also has multiple components What Happens When Rachel Looks Up a Phone Number Psych 355, Miyamoto, Spr '18 5

6 What happens as Rachel looks up a phone number? (a) She looks at the page in the phone book. Perceptual information enters sensory memory. (b) She pays attention to the relevant phone number. The number is stored in short-term memory (STM). (c) She dials the phone number while maintaining the number in STM (rehearsal). UW Psych 355, Miyamoto, Spr '18 Example Continued 6

7 What happens as Rachel looks up a phone number? (d) She memorizes the phone number (stores the number in longterm memory or LTM). This process is called encoding. (e) Days later, she retrieves the number from LTM. Return to the Modal Model UW Psych 355, Miyamoto, Spr '18 7

8 The Modal Model (Atkinson & Shiffrin, 1968) Goldstein Figure 5.2 Control Processes, e.g., rehearsal Input Sensory Short-Term Long-Term Output: Speech & Actions The Modal Model of (Atkinson & Shiffrin, 1968) Sensory brief storage of current perceptual inputs. STM short-term storage of current mental activity STM or Working (WM) has multiple components LTM long-term storage of experiences, thoughts, facts LTM also has multiple components Distinction Between STM and LTM Psych 355, Miyamoto, Spr '18 8

9 Distinction Between STM & LTM Standard STM example: Remember the following words: hand, chair, reed, bottle We will wait, perhaps, 15 seconds. Then I ll ask you to tell me the words that you read in the order that they were written. Another STM example: You know where you are right now and what you are doing there. You are actively processing this information (along with other thoughts). LTM refers to a variety of memory processes that allow retrieval of memories that are not currently preserved in STM. Illustration of LTM vs STM Distinction from Goldstein Textbook UW: Psych 355, Miyamoto, Spr '18 9

10 Figure 6.1: Example of the STM/LTM Distinction LTM STM UW: Psych 355, Miyamoto, Spr '18 List of Functions That Are Included in LTM 10

11 LTM Includes... Important information about the self and events in the world, but also,... Trivial information about what has happened in the recent past, e.g., what was the picture at the beginning of the lecture), and also,... Semantic knowledge, e.g., what is an apple, a pencil; which is bigger, a mouse or a moose; etc. How to do things: Tie your shoes, drive a car, dial a phone number, cook a meal,... Learned associations that are not explicit, e.g., the atmosphere of a dentist s office makes you feel apprehensive. Diagram of Modal Model Next Topic = Sensory UW: Psych 355, Miyamoto, Spr '18 11

12 The Modal Model (Atkinson & Shiffrin, 1968) Control Processes, e.g., rehearsal Input Sensory Short-Term Long-Term Next Output: Speech & Actions Sensory brief storage of current perceptual inputs. STM short-term storage of current mental activity STM or Working (WM) has multiple components LTM long-term storage of experiences, thoughts, facts LTM also has multiple components UW Psych 355, Miyamoto, Spr '18 Definition of Sensory 12

13 Sensory Example: Sparkler trail or flash image in a dark room. Sensory memory is the retention of the effects of sensory stimulation. Very brief less then 1 second. Sensory memory is partly due to processes that are close to level of the receptors, but it has a major component that is central. "Central" means at the level of the cortex, i.e., at the level of the visual cortex for visual stimuli; at the level of the auditory cortex for auditory stimuli, etc. What are the capacity limits for visual sensory memory? How much information is stored? How long can it be stored? Diagram: Where Is the Capacity Limit in the System? UW Psych 355, Miyamoto, Spr '18 13

14 Evidence for a Capacity Limit on Sensory or Short-Term Suppose a letter array is flashed on the screen to the right. Can you name all of the letters in a specific row, e.g., in Row 3? E R U P W I N Q M X T V Y S O K Continue with Slide with Example of Pre-Cueing Psych 355, Miyamoto, Spr '18 14

15 Evidence for a Capacity Limit on Sensory or Short-Term Suppose a letter array is flashed on the screen to the right. Can you name all of the letters in a specific row, e.g., in Row 3? The task is easy if I tell you the row to remember before I flash the letter array. (See letter array to the right.) Pay attention to Row 2. Answer: P E C Z E R U P W I N Q M X T V Y S O K O A W N P E C Z H X M U V F B I Same Problem is Hard If You Must Remember All 16 Letters Psych 355, Miyamoto, Spr '18 15

16 Evidence for a Capacity Limit on Sensory or Short-Term Suppose a letter array is flashed on the screen to the right. Can you name all 16 letters in the array? The task is hard if I ask you to remember all 16 letters in the letter array. (See letter array to the right.) What were the 16 letters in the array? # # # # # # # # # # # # # # # # U R V X Y Z Q M I C D W L T J N Psych 355, Miyamoto, Spr '18 Is the Capacity Limit on Sensory or STM? 16

17 Controversy: Is the capacity limit a limit on sensory memory, or short-term memory? Limit here? Transfer too slow? Limit here? Input Sensory Short-Term Long-Term We have evidence that a capacity limit exists: You can accurately report a pre-selected 4 letters from a 12 letter array, but you can't accurately report all 12 letters. Is there a limit on the capacity of sensory memory? UW Psych 355, Miyamoto, Spr '18 Sperling's Partial Report Paradigm 17

18 UW Psych 355, Miyamoto, Spr '18 18 Sperling's Partial Report Paradigm Sperling s Partial Report Procedure (Paradigm) Digression on Terminology: An "experimental paradigm" is a type of experiment. Often there will be many experiments that all use the same paradigm. Purpose of Sperling's partial report paradigm: To determine what are the limits on the capacity of sensory memory. To save lecture time, I may cut short the following explanation of Sperling's partial report paradigm. (To discuss, or not to discuss?) Students will be responsible for knowing its purpose and its conclusions. Notice use of timing of stimulus to explore the way the information is processed. Sperling s partial report paradigm is important for perceptual psychology. Not so important for higher cognitive processes.

19 Psych 355,, Miyamoto, Spr '18 19 More-Or-Less Unlimited Capacity of Sensory Measuring the Capacity & Duration of Sensory Sperling's Partial Report Paradigm 3 x 4 array of letters displayed for 50 ms (0.05 seconds) The image of the array persists in sensory memory even after it is physically gone. How much information is stored in sensory memory? How long does the information last in sensory memory?

20 Psych 355,, Miyamoto, Spr '18 20 Sperling's Paradigm: Whole Report Condition What is the Capacity of Sensory? How much information is stored in sensory memory? Capacity is very large, but there is no known way to quantify how large. Remainder of this discussion addresses the question: How long does the information last in sensory memory?

21 Psych 355,, Miyamoto, Spr '18 21 Partial Report Condition: 0.0 Delay in Tone Cue Whole Report Condition: No Cues Are Given 3 x 4 array of letters displayed for 50 ms (0.05 seconds) Subject must try to report all 12 letters in the array. Result: 4.5 letters correctly reported out of 12 possible (average result)

22 Psych 355,, Miyamoto, Spr '18 22 Partial Report Condition: 1.0 Delay in Tone Cue Partial Report Condition: 0.0 Sec. Delay in Tone Cue 3 x 4 array of letters displayed for 50 ms (0.05 seconds) Simultaneous with disappearance of array, subject hears a tone High tone Report Row 1 Medium tone Report Row 2 Low tone Report Row 3 Result: 3.3 letters correctly reported out of 4 possible (average result)

23 Psych 355,, Miyamoto, Spr '18 23 Summary of Results for Duration of Sensory Condition 3: Partial Report, 1 Sec. Delay in Tone Cue 3 x 4 array of letters displayed for 50 ms (0.05 seconds) 1 second after disappearance of array, subject hears a tone High tone Report Row 1 Medium tone Report Row 2 Low tone Report Row 3 Result: 1.0 letters correctly reported out of 4 possible (average result)

24 Psych 355,, Miyamoto, Spr '18 24 Diagram of Standard Model: Conclusion re Capacity of Sensory Summary of Results for Duration of Sensory Amount of information in sensory memory decreases over time. By a little more than 1.0 seconds it is gone. (How do we know that the capacity of sensory memory is very large? With 0 delay, you can cue any position in the array and get accurate memory of what is at that position.)

25 Conclusion of Partial Report Experiment Very large, possibly unlimited capacity. Information decays to 0 in about 1 second. Control Processes Input Sensory Short-Term Long-Term Output: Speech/Actions What Is Meant By Capacity Limits on? UW Psych 355, Miyamoto, Spr '18 25

26 What Is Meant by Limits on Capacity? Limit on memory capacity refers to a limit on the amount of information that can be held in memory. Not the amount of information that can be input to memory (encoding), and not the amount of information that can be retrieved from memory (retrieval). Sensory memory very large, approximately unlimited Short-Term memory? Long-Term memory very large, approximately unlimited Next: Introduction to Short-Term & Working Overview of Short-Term & Working UW Psych 355, Miyamoto, Spr '18 26