Upcoming Reading

Read experiment 1 in the article by Lee Brooks for Thursday March 29th

Are All Subliminal Messages Intentionally Inserted?

• These messages tend not to be clear and obvious

Are All Subliminal Messages Intentionally Inserted?

• These messages tend not to be clear and obvious

• Could it be that our brains mistakenly see or hear messages that aren’t really there?

Are All Subliminal Messages Intentionally Inserted?

• These messages tend not to be clear and obvious

• Could it be that our brains mistakenly see or hear messages that aren’t really there?

• Do brains make stuff up!?

Are All Subliminal Messages Intentionally Inserted?

• These messages tend not to be clear and obvious

• Could it be that our brains mistakenly see or hear messages that aren’t really there?

• Do brains make stuff up!?

Absolutely! All the time.

Are All Subliminal Messages Intentionally Inserted?

• Is there really a dog or are the spots enough like a dog for your brain to fill in the rest?

Are All Subliminal Messages Intentionally Inserted?

• Some other examples you already know about :

• Missing fundamental, color constancy, size constancy, the Kaniza triangle, stereo depth, the blindspot, illusory conjunctions

Subliminal “Messages” Where you Least Expect Them

• How did Vokey and Read test the idea that subliminal messages might just be a case of mistaken perception?

Subliminal “Messages” Where you Least Expect Them

• They examined passages from various sources (Jabberwokey and the 23rd Psalm) played backwards to identify candidate messages

Subliminal “Messages” Where you Least Expect Them

• Listeners were given each passage (backwards) and asked to listen for 12 possible messages

• Listeners detected “messages” in the appropriate passage when primed to expect it

Subliminal “Messages” Where you Least Expect Them

• Interpretation: Your brain is remarkably good at “active construction” of patterns amid a background of noise.

Subliminal “Messages” Where you Least Expect Them

• Interpretation: Your brain is remarkably good at “active construction” of patterns amid a background of noise.

• Creative listening by (well-meaning?) public censors can go very wrong

Subliminal “Messages” Where you Least Expect Them

• Consider the trial of Judas Priest– Band sued for inserting the message “do it” which

allegedly lead to the suicide of two teens

Listen for “Do It” The “do its”

Subliminal “Messages” Where you Least Expect Them

• Consider the trial of Judas Priest– Band sued for inserting the message “do it” which

allegedly lead to the suicide of two teens• Band acquitted on the basis of expert

testimony

Expert Testimony !

Subliminal “Messages” Where you Least Expect Them

• With enough creativity and patience one can see “subliminal messages” just about anywhere:

Subliminal “Messages” Where you Least Expect Them

• Our perceptual mechanisms are great at extracting meaningful images from noisy stimuli. For example - the famous face on Mars:

Viking, 1976

Subliminal “Messages” Where you Least Expect Them

• Given a clearer picture it looks a lot less like a face:

Mars Global Surveyor, 2001

The message is…

• Don’t be fooled by messages!

Memory

Overview of Memory

• Atkinson-Shiffrin Model

Sensory Signals

Sensory Memory

Short-Term Memory

Long-Term Memory

ATTENTION

REHEARSAL

RETRIEVAL

Sensory Memory

Supplementary reading:•Cognition (on reserve)

• Averbach and Sperling (course pack) Part 1

Capacity

• Describe a simple experiment that could measure the capacity of “memory”

Capacity

• Describe a simple experiment that could measure the capacity of “memory”

• Briefly present some letters or digits and then ask the subject to report them– Called “whole report”

Capacity

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Capacity

F S F EG S A UT O C G

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Capacity

“Recall as many letters as you can”

Capacity

• George Sperling - Systematic investigation of memory capacity

– Result: subjects accurately recall about 4 items

– What can you conclude from this result?

– Maybe subjects can only hold about 4 items?