Sensory Memory - Wofford Collegewebs.wofford.edu/steinmetzkr/teaching/310PDFs/Sensory.pdf3 Learning...

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Sensory memory Ch 5 p116-123

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

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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

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•  Span and Duration of Iconic Memory"•  Processing of Iconic Memory: Brain or Retina?"•  What Influences Iconic Memory? "



Sensory Memory"•  Very short-term

storage of information •  within the sensory

systems •  allow us to perceive

the information

Information in the world

Sensory Memory

(very short term; .5-2 sec maximum)

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Sensory Memory" •  Decays (fades away) the fastest of all memory types that we will talk about •  Depends on the sense that we are talking about

Information in the world

Sensory Memory

(very short term; .5-2 sec maximum)

It depends on the sense: • Vision: iconic memory • Auditory: echoic memory

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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/


•  Span and Duration of Iconic Memory"• What Influences Iconic Memory? "



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

Photography: shutter speed

1/30 1/500

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Perceptual Span"How much can we remember from a single glance?

George Sperling (1960)

H P D S

K O Q D

J M V P Guesses?

Sensory Memory"A display with 16 letters will appear briefly. Write

down as many letters as you can remember.

Look at the screen.

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

Sensory Memory"

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“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”

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How did you do?

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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"

Sensory Memory • Delayed parGal report method • What was this? • What did it show?

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

Sensory Memory"





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

"""

Sensory Memory"

Is it even memory at all?

Sensory Memory"

+ +

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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?"

""

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"

Sensory Memory"

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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?"

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

of retina"

Sensory Memory"

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"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)"

Sensory Memory"

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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"

"

Sensory Memory"

• How does this relate to change blindness?

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

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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.” “Yes, I am.” “What did I just say?” “You’re not listening, Kate.” “Before that?” “Don’t know.” “This is important.” “Sorry.”

•  You don’t have to be consciously paying attention to have sensory memory!!

•  It just has to enter your sensory system!!

From A Ghost In the Machine by Caroline Graham

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"""How do we know whether echoic memory is

influenced by meaning, or only by the auditory percepts?"

"

Sensory Memory"

Echoic Memory – Suffix Effect"Ask participants to listen to a series of numbers

End the list either with a buzzer noise or with a speech sound

Then ask participants to repeat the numbers

Interference from similar types of sounds as in the list (speech)

No interference from different types of sounds (buzzer)

0!10!20!30!40!50!60!70!80!90!

100!

1! 2! 3! 4! 5! 6! 7! 8! 9!

Prop

ortio

n C

orre

ct!

Serial Position!

buzzer suffix!speech suffix!

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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

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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

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Sensory v. STM Sensory memory

•  Capacity •  Iconic: 17+ items •  Echoic: 5+ items

•  Duration •  Iconic: 500ms •  Echoic: 2s

•  Unprocessed •  Accurate •  Passive

Short-term memory

•  Capacity •  1-4 items •  7 +/- 2 items

•  Duration •  30s without rehearsal

•  Can be manipulated •  Can be inaccurate •  Active

Sensory Memory - Wofford Collegewebs.wofford.edu/steinmetzkr/teaching/310PDFs/Sensory.pdf3 Learning...

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