Sensory memory Ch 5 p116-123

Memory

• Book: “Life is all memory” • Do you agree? • What would a life without memory be like? • hp://www.youtube.com/watch?v=pv0B0Z6mZrQ

1 Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

Information-processing approach

• Atkinson & Shiffrin (1968): Modal model of memory • Sensory memory • Short-term memory • Long-term memory

2 Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • Processing of Iconic Memory: Brain or Retina? • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

Sensory Memory Information in the world • Very short-term storage of information • within the sensory systems Sensory Memory • allow us to perceive the information (very short term; .5-2 sec maximum)

3 Sensory Memory Information in the world

• Decays (fades away) the fastest of all memory types that we will talk about Sensory Memory

• Depends on the sense that (very short term; .5-2 we are talking about sec maximum)

It depends on the sense:

• Vision: iconic memory • Auditory: echoic memory

4 Sensory memory

• Purpose? • Persistence: beyond physical duration • Collect and hold until further processing • Integration • Provides stability for senses • Fill-in the blanks (e.g. blinks) • Radio Lab Short: Blinks http://www.radiolab.org/blogs/radiolab-blog/ 2009/oct/05/blink/

Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

5 Iconic memory • Lightning • Movie projectors – Flickers -> Flicks

Photography: shutter speed

1/30 1/500

6 Perceptual Span

How much can we remember from a single glance?

H P D S K O Q D

J M V P

George Sperling (1960) Guesses?

Sensory Memory

A display with 16 letters will appear briefly. Write down as many letters as you can remember.

Look at the screen.

7 8 Sensory Memory

How many could you remember? What was your subjective impression?

9 “Whole report” procedure: Ask participants to recall as many letters as they can

George Sperling (1960)

Sensory Memory

A display with 16 letters will appear briefly.

Afterward, I will ask you to recall either The top row, The middle row, or The bottom row

Try to remember as many letters as possible in the row corresponding to what I say: “Top, Middle or Bottom”

10 Q G Z K

S E B R

L X V F

11 Q G Z K

S E B R

L X V F

12 Q G Z K

S E B R

L X V F

13 Q G Z K

S E B R

L X V F

How did you do?

14 Sensory Memory

Sperling’s “Partial report” procedure: • recall as many letters as they can from a particular line • high tone = top line; middle tone = middle line; low tone = bottom line) **Because participants don’t know in advance which line will be tested, this suggests that all letters are briefly held in a sensory store

Sensory Memory

• Delayed paral report method • What was this? • What did it show?

15 Sensory Memory

Iconic memory --> very short duration (~500ms) --> rapid decay (only enough time to recall 3-4 letters) --> very large capacity

Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

16 Sensory Memory How do we know whether iconic memory results from processing in the brain or retina?

Is it even memory at all?

Sensory Memory

+ +

17 Sensory Memory

• Is Iconic memory just an afterimage? • Is it something that happens in the brain or just an effect of our photoreceptors in the retina?

Sensory Memory

How do we know whether iconic memory results from processing in the brain or retina? 1) Visual after-effects in the retina have color reversal; not true of iconic memory

18 Sensory Memory • Retinal effects are eye- specific

• Brain effects are visual- field-specific

Sensory Memory • What if we use a color mask for one eye? • If it doesn’t interrupt visual memory what would that mean? • If it does what would that mean?

19 A X Q C

M R F B

G S D W

20 A X Q C

M R F B

G S D W

Sensory Memory

1) Brightness masks disrupts iconic memory only if letters and mask shown to same eye - suggests iconic memory at the level of retina

21 Z D S A

B Y V M

L C X T

## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ##

22 Z D S A

B Y V M

L C X T

Sensory Memory 1) Brightness & pattern masks disrupt iconic memory - brightness masking works only if show letters & mask to same eye (so suggests level of retina) - Pattern masking works even if show letters to one eye & mask to the other eye (so suggests level of brain)

23 Sensory Memory

Does iconic memory result from processing in the brain or retina? Some aspects of iconic memory may occur at level of retina, but that at least some features of iconic memory are due to processing in the brain

• How does this relate to change blindness?

24 Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

Echoic memory

• How would you study echoic memory? • Questions • Methods • IVs, DVs • Hypotheses

25 Echoic Memory

Have you ever asked someone “What?” and then almost immediately realized that you did know what they just said?

This ability highlights echoic memory (sensory memory for auditory information)

An Example “You’re not listening.” “What?” “You’re not listening, Kate.” • You don’t have to “Yes, I am.” be consciously “What did I just say?” paying attention to “You’re not listening, Kate.” have sensory “Before that?” memory!! “Don’t know.” • It just has to enter “This is important.” your sensory “Sorry.” system!!

From A Ghost In the Machine by Caroline Graham

26 Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • Processing of Iconic Memory: Brain or Retina? • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

27 Sensory Memory

How do we know whether echoic memory is influenced by meaning, or only by the auditory percepts?

Echoic Memory – Suffix Effect Ask participants to 100! 90! listen to a series of 80! numbers 70! 60! buzzer suffix! 50! speech suffix! 40! 30! End the list either

Proportion Correct ! Proportion 20! with a buzzer 10! noise or with a 0! 1! 2! 3! 4! 5! 6! 7! 8! 9! speech sound Serial Position!

Interference from similar types of Then ask sounds as in the list (speech) participants to No interference from different types of repeat the sounds (buzzer) numbers

28 Echoic Memory

What does it mean for suffix to be similar or different? context/meaning-based similarity? - depends on how people interpret the sound “baa” as animal noise does not interfere; but “baa” human sound does; “waa” trumpet noise does not interfere; but “waa” as human sound does - so echoic memory is not only perceptual; it is influenced by the meaning of the auditory information

Echoic memory

• Why do we care? • Allows more time to analyze stimulus • Able to process significantly more • Practical implications • Use silent rehearsal to slow rate of decay • Use to distinguish clinical populations: e.g. schizophrenia

29 Learning Objective Topics • Atkinson & Shiffrin Model • What is Sensory Memory? • Iconic • Span and Duration of Iconic Memory • Processing of Iconic Memory: Brain or Retina? • What Influences Iconic Memory? • Echoic • Span and Duration of Echoic • What Influences Echoic Memory? • Iconic and Echoic Compared

Echoic vs. Iconic Memory

Echoic memory lasts longer (~2-5 sec for echoic vs. ~500ms for iconic)

Echoic memory has lower capacity (iconic nearly limitless)

***Both Echoic and Iconic are influenced by stimulus meaning; not purely retention of meaningless, perceptual information

30 Sensory v. STM

Sensory memory Short-term memory

• Capacity • Capacity • Iconic: 17+ items • 1-4 items • Echoic: 5+ items • 7 +/- 2 items • Duration • Duration • Iconic: 500ms • 30s without rehearsal • Echoic: 2s • Unprocessed • Can be manipulated • Accurate • Can be inaccurate • Passive • Active

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