Lecture 10 - Memory + Attention

Question 1

Sensory memory

Answer 1

● Iconic Memory (visual)… after image
○ 250-300ms
● Echoic Memory (auditory)
○ Several sec
● Olfactory, gustatory, tactile?

● Content: Iconic >= 12 items when prompted
● Duration:
○ Iconic: 250-300ms
○ Echoic: 1+ sec
● Decay: max 1s (relisten to this part/see slide)
● Decreased by masking/blinking

Distractors affect sensory memory (masking)
But cues can help
Blinking affects sensory memory (like a distractor)… worse than staring at a white slide (masking)

Summary:
Sensory Memory:
○ Iconic (~300ms), 12x
○ Echoic (>1s)

Question 2

Working memory

Answer 2

Duration: around 18 seconds (when distracted with other task)
-Rehearsing overcomes decay
Capacity: 7+-2 items
Recognizing patterns (chunking) can overcome capacity
A and K, T and P often mistaken for each other… acoustic coding
Remember apple better in tulip condition than orange condition… semantic coding
3d models… visual coding
Scanning
-serial… longer list, higher reaction time
-parallel… size of list (up until magic number) doesn’t matter
-terminating… do you finish as soon as find the right item (in positive condition (yes), would expect the reaction time to be lower)
-exhaustive…. Do you go over the whole list regardless of where the item is
Working memory is SERIAL! EXHAUSTIVE!

Summary:
Working Memory:
○ 7+/-2
○ Coding: acoustic/semantic/visual
○ Serial, exhaustive
○ <18s or rehearse

Question 3

Long-term memory

Answer 3

Types:
-Explicit/Declarative
–Semantic
–Episodic
-Implicit
–Procedural

● Coding:
○ Explicit: various (distributed representation)
○ Implicit: production rules (cerebellum)… if-then response
● Capacity:
○ ̄_(ツ)_/ ̄
○ “One billion bits”? – (Landauer, 1986, “How much Do People Remember? Some Estimates of the
Quantity of Learned Information in Long-term Memory”)

Lashley - Long-term memory location (‘‘engram’’)
Train rat, remove brain part, retrain
Time to retrain rat depends on size of the brain lesioned
Rat doesn’t forget
Different brain areas store l-t memory
Equipotentiality… brain areas can take over

Learning - Cell level
Hebb rule: neurons that fire together wire together
Hebbian learning
Long-term potentiation (LTP): If a cell fires at a high frequency, the receiving cell develops more receptors (the cell changes)

Learning - Brain areas
Hippocampus = important for memory consolidation
Patient H.M.
Removal of hippocampus to cure epilepsy
Complete anterograde amnesia (old memories intact, but unable to form new memories)
Hippocampus also important for sleeping
Corkin, 1984

Summary:
Long-term Memory:
○ Explicit: Semantic, Episodic
○ Implicit: Procedural
○ Distributed, slowly decaying
○ Hebbian Learning
○ Hippocampus

Question 4

Memory models

Answer 4

The Modal Memory Model
Stimulus Input goes to Sensory Memory. Types of Sensory Memory = Visual (Iconic) and Auditory (Echoic). Goes to Short-Term (Working) Memory. Control processes of WM are rehearsal, coding, decisions, retrieval strategies. From there, can be a Response Output or Encoding into Long-Term Memory. Then, Retrieval from Long-Term Memory into Short-Term Memory.

Criticism of this model: “too much model”

The Working Memory Model
Central Executive (supervises and controls processes)
-Phonological Loop
–Articulatory Loop (rehearsal of processing of auditory information)
–Acoustic Store
-Episodic Buffer
-Visuo-Spatial Sketchpad (processing of visual information)

Visuo-spatial sketchpad - Executive control sytem - Articulatory loop
Can be independent! (visuo-spatial sketchpad and articulatory loop)

Kosslyn & Schwartz - Theory of Visual Imagery
Similar to Marr’s vision
Deep Representation made of:
-Literal Encodings = memory of images
-Propositional Encodings = more language based (cat has a tail) (kinda like semantic)
Leads to Image Generation and then
-Image Inspection = zoom in, shift, rotate
-Image transformation = adding and removing items
Visual Buffer (Surface Representation)
Larger distance between two points in mental image = longer processing time (example with bus)

Question 5

Summary

Answer 5

Summary
● Memory Factors: Duration, Capacity, Coding/Content
● Sensory Memory: Iconic (~300ms), 12x, Echoic (>1s)
● Working Memory:
○ 7+/-2
○ Coding: acoustic/semantic/visual
○ Serial, exhaustive
○ <18s or rehearse
● Long-term Memory:
○ Explicit: Semantic, Episodic, Implicit: Procedural
○ Distributed, slowly decaying
○ Hebbian Learning
○ Hippocampus
● Models: Modal Memory Model, Working Memory Model, Theory of Visual Imagery