1. Human Cognitive Architecture & Working Memory
Psych 605 Advanced Human Learning
Neil H. Schwartz, Ph.D.

2. The Metaphorical Model of HCA
Cognition
Encoding
Long-Term
Store
Control Processes
Short-Term
Store
Environment
Sensory
Register
Retrieval

3. What do we know about the model?

4. Original Conceptions Broadbent (1958) conceived the model.
Concerned with how we attend and retain.
A “pipeline” model: E  SR  STS  LTS
Components of the model are separate, such that variables effect memory in some stores and not others.
Information is held in an unlimited capacity SR, with some selected for further coding.
This further coded information is held in a limited-capacity STS.
Then, the coded information is filed in a permanent LTS composed of prior knowledge that is generally organized.
Atkinson & Shiffrin (1968) refined Broadbent’s (1958) model. They added:
Control processes manage the transfer of information between stores.
Management of the control processes are voluntary and effortful.
The control processes operate to:
Switch attention to selected information for processing
Maintain relevant information in STS
Retrieve information from LTS into STS.

5. Problems with the Model
The model is now seen as obsolete as originally conceived. (Broadbent, 1984)
Learner is active, not passive.
Processing is not exclusively “bottom-up”, but also “top down”.
Processing is dynamic, strategic, and flexible.
Processing is not simply additive.
Some processing is sequential, but other processing is parallel.
There is more interaction between the stores than originally conceived.
Awareness is not always required for content to be in the short-term store.

6. Inside the Cognitive System
Prior
Knowledge
bottom-up
Sailboat
Curtins
Pattern
Recognition
Feature
Processing
top-down
sails & hull ?
fabric & scallops?

7. Problems with the Model
It is not clear that, if SR and STS are actually distinct entities, what constitutes the demarcation.
The STS is not essential for access to LTS.
Timing and order of information flow is not clear.
For Broadbent, SR fades quickly; STS fades slower; LTS is permanent.
For Shiffren SR is coded using LTS information which forms a “trace” in STS.
Feature detectors of SR are very quickly “tuned” by prior knowledge from the LTS
Features and concepts in LTS can be automatically activated by incoming stimuli (without awareness).
Features and concepts can be held in STS without awareness.

8. The Way the Original Model Evolved
Long-Term
Store
Short-Term
Store
STIMULUS
Sensory
Register PK
STIMULUS PK

9. All the action is in… Cowan, 1988 Baddeley & Hitch, 1974
Sensory
Register
Short-Term
Store
Short-Term
Store
WORKING MEMORY
Long-Term
Store
2 Models
Cowan, 1988
Baddeley & Hitch, 1974

10. What is the difference between STS and WM?

11. STS WM
A faculty of mind that can temporarily hold a limited amount of information in a very accessible state with or without awareness.
A concept term derived from Miller et al. (1960) to stand for the way memory is used to plan and carry out behavior.
A pattern of neural firing where the firing pattern, or cell assembly, is active.
The concept was made popular among researchers by Baddeley & Hitch (1974) when they realized that a single module could not account for all kinds of temporary memory.
Temporary Storage
Storage & Manipulation

12. How does WM work?

13. Principles of the Embedded Processing Model
Principle 1: Working memory information derives from faculties that are hierarchically arranged. These faculties are: (1) LTM, (2) An activated subset of LTM, (3) A subset of activated memory that is under the light of attention and awareness.
Three
faculties
Different
Processing limits
Principle 2: Each faculty has different processing limits. The focus of attention: capacity limited. Activated subset of LTM: time limited. These limitations really show up under non-optimal conditions (e.g. interference between items with similar features).
Controlled by
voluntary & involuntary
processes
Principle 3: Focus of attention is controlled conjointly by: (1) voluntary processes and (2) involuntary processes. Voluntary processes are regulated by the central executive system. Involuntary processes are controlled by the attentional orienting system.
Unchanged stimuli
activate LTM w/o awareness
Principle 4: Unchanged and unimportant physical features of stimuli still activate some features in LTM, but without awareness.
Principle 5: Awareness influences processing. In perception, awareness increases the number of features encoded. In memory, awareness allows new episodic representations to be available for explicit recall.
Awareness influences
processing

14. Cowan: Embedded Processes Model
Central Executive
(directs attention and controls voluntary processing)
Attention can be directed outward to
stimuli, or inward to long term memories.
Actions
Controlled a
Focus of Attention
No “filter” is needed; physically unchanged stimuli do not elicit attention (b & c), with the possible exception of significant signals. Unchanged stimuli can enter the focus of attention through voluntary means (a).
Long-Term storage of some coded features occurs auto-matically (b & c). Attentive processing (a & d) results in more elaborate encoding– critical for voluntary retrieval, episodic storage. b
Automatic c d
Activated Memory
(Short-Term Store)
Voluntarily Attended
Dishabituated
Habituated
Habituated
Long-Term Store
Stimuli a
Brief
Sensory
Store
Unchanged Stimuli b
Initial phase of sensory storage lasts only several hundred milliseconds (left).
Second phase is one type of activated memory (above), both sensory and semantic activation may last some seconds. c
Novel Stimuli d

15. Baddeley: Tripartite Model
Long-Term Store
Central Executive
Attention:
focus, divide, switch
Episodic Buffer
Visual and spatial
Visual code
Binding
Create & Maintain
Binds and holds
multidimensional codes
(temporary or durable)
Linguistic code
Binding
Language-based
Speech – heard
& spoken
Perhaps, haptic
and kinesthetic
Visuospatial
Sketchpad
Phonological
Loop
Also, lip reading
and gestural signs
Perhaps, environmental
sounds and music

16. Baddeley’s New Model Central Executive Episodic Buffer VSSP
Articulatory
Phonological Loop
Speech
Sign
Lip reading
Music
Environmental
sound
Visual
Spatial
Haptic?
Smell?
Taste?
Color
Shape
Tactile
Kinesthetic

17. Which model of WM is better?

18. Working Memory: Cowan vs. Baddeley
Short-term memory is derived from a temporarily activated subset of information in long- term memory.
This activated subset may decay as a function of time unless it is refreshed, although evidence for decay is tentative at best.
A subset of the activated information is the focus of attention, which appears to be limited in chunk capacity.
New associations between activated elements can form the focus of attention.
Baddeley
Verbal-phonological (VP) and visual- spatial (VS) representations are held separately, managed and manipulated with the help of attention-related processes, in the central executive (CE).
CE was first believed to have a general temporary memory component and a system directive component. Then, the episodic buffer replaced the memory component. The CE is reconceived as the directive (metacognitive) component.
Some codes are an activated subset of LTM, some are not.
Complex interactive system providing an interface between cognition and action, capable of handling information in a range of modalities and stages of processing.

19. What is Activated LTM?
Maintaining structural representations by dynamic bindings.
Manipulating the structural representations.
Flexibly reconfiguring the structural representations.
Partially decoupling the structural representations from LTM.
Controlling LTM retrieval.
Encoding new structures into LTM.
Oberauer, (2010)

20. Working Memory: Cowan vs. Baddeley
Memory Mechanism
Cowan
Baddeley
Short-term Storage Mechanism
Activated Memory
(time-limited by decay)
Phonological Loop/
Visuospatial Sketchpad
(temorary hold)
Chunk-based
Mechanism
Focus of Attention
(chunk-capacity limited)
Episodic Buffer
(binding)
Independent
of each other