Coming Up:

Read: The Lost Mariner by Oliver Sachs

Repressed Memories by Elizabeth Loftus

Overview of Memory

• Atkinson-Shiffrin Model

Sensory Signals

Sensory Memory

Short-Term Memory

Long-Term Memory

ATTENTION

REHEARSAL

RETRIEVAL

Recap: Short-Term memory

• Span of “seven plus or minus two” must be qualified by rate of speech

• Primacy and recency effects influence which items are best recalled

• Interference depends in part on semantic meaning

Coding in STM

• How is information coded in STM? What is the “file format”?

Coding in STM

• Clues about coding in STM:– # of items stored in STM depends on rate of speech

Coding in STM

• Clues about coding in STM:– # of items stored in STM depends on rate of speech– phonological similarity effect: similar sounding words

are harder to store/recall than different sounding words

Coding in STM

• Clues about coding in STM:– # of items stored in STM depends on rate of speech– phonological similarity effect: similar sounding words

are harder to store/recall than different sounding words

– “counting backwards” prevents mental rehearsal

Coding in STM

• Clues about coding in STM:– # of items stored in STM depends on rate of speech– phonological similarity effect: similar sounding words

are harder to store/recall than different sounding words

– “counting backwards” prevents mental rehearsal

What does this suggest about the “format” of STM?

Coding in STM

• It seems that information can be stored in a linguistic or phonological form

Coding in STM

• It seems that information can be stored in a linguistic or phonological form

Must it be stored this way?

Delayed Match-To-Sample

Remember the locations of the letters

Delayed Match-To-Sample

A

Q

P

Delayed Match-To-Sample

Delayed Match-To-Sample

Was there a letter at the location of the star?

Coding in STM

• It is also possible to “keep in mind” non-verbal information, such as a map

Are there two different STM systems?

A Modular Approach to STM

Articulatory Loop

Central Executive

Visuospatial Sketchpad

Introduces the notion of “Working Memory” because emphasis is on performing mental operations on the information encoded

A Modular Approach to STM

Articulatory Loop

Central Executive

Visuospatial Sketchpad

Experiment 1 in the article by Lee Brooks demonstrates a double dissociation between Articulatory Loop and Visuospatial Sketchpad

Working Memory “Modules”

• Lee Brooks: interference between different representations in STM (Experiment 1)– Memory Representation• verbal task: categorize words in a sentence• spatial task: categorize corners in a block letter

– Response Modality• verbal response: say “yes” or “no”• spatial response: point to “yes” or “no”

Working Memory “Modules”

• Verbal Task: indicate if each word is or is not a noun– “I went to the store to buy a loaf of bread.”– N N N N Y N N N Y N Y

Working Memory “Modules”

• Spatial Task: indicate if each corner points outside

FY

Y

Y

N

Working Memory “Modules”

• In both tasks the information needed must be maintained (represented) in working memory

Working Memory “Modules”

• Response Modalities:

Say: “yes” “no” “no” Point to: Y or N

Verbal Spatial

Y NY NY NY NY N

Working Memory “Modules”

• Both response modalities also engage working memory

Working Memory “Modules”

• Prediction: – There should be interference when response

modality and task representation engage the same module

– if there is only one kind of module, then there should be interference between every pairing of representation to response

Working Memory “Modules”

• result: a cross-over interaction (double dissociation)

Perf

orm

ance

Response Modality

Verbal Spatial

Spatial Representation(categorize corners)

Verbal Representation(categorize words)

Working Memory “Modules”

• Interpretation:– supports notion of modularity in Working Memory

(visuospatial sketchpad / articulatory loop work independent of each other)