The Architecture of Human Memory

Information Processing TheoryA Closer Look

Epistemic Heritage To The ModelMemory research dates back to 1885 with

Hermann Ebbinhaus who looked at memory in terms of nonsense symbols.

In the 1950s cognitive scientists began creating models that acknowledge the stages of acquisition storage and retrieval.

The increasing influence of computers were clearly reflected in these models that came to be known as Information Processing Models

One of the most influential models was the modal model proposed by Atkinson and Shiffrin in 1968.

Modal Model

Sensory memoryShort termMemory

Long TermMemory

DeclarativeKnowledge

ProceduralKnowledge

Conditional Knowledge

retrieval

encoding

Rehearsal

Criticisms of the Modal ModelProposes three separate structures in

memory ,short term, long term and sensory.

Assumes that information only flows one way in a linear fashion. It is believed that information in long term memory influences short term memory and information is processed concurrently in short term and long term memory

Does not correspond to any one area of the brain.

Description of Sensory MemorySensory memory-”is a system that briefly

holds stimuli in sensory registers so that perceptual analyses can occur before the information is lost”.

Two Types of Sensory RegistersVisual registers are very limited.

visual memory can only process 7 to 9 pieces of information at any given time.

Information is only available briefly 0.5 seconds

Auditory Registers are limited.Auditory registers can only process 5 to 7

pieces of information.Auditory information can only be stored for up

to 4 seconds before the information becomes unavailable.

Steps in sensory memory process

Perception enables us to identify incoming perceptual stimuli and direct attention to them.

Pattern recognition enables us to associate perceptual information with a recognizable pattern, then it is forwarded to short term memory.

Description of Short Term MemoryShort term memory is the place where

information is stored for meaning. It has limited capacity and duration. The current name for short term memory is

working memory. It can only hold 7 chunks plus or minus two

(Miller). The duration is not limited by time so much

but by interference and capacity overload.– but generally restricted to 30 seconds.

Postulation about short term and sensory memoryMemory systems are functionally separateAttention is limitedProcess are controlled and automatic

Automatic task are much easier to perform and require much fewer cognitive resources (e.g. strategies)

Meaning is constructed based on context and prior knowledge

Working Memory Baddeley replaced the

unitary short term store with a working memory system

Central executive, which is assumed to be an attention-controlling system.

Visuospatial sketch pad manipulates visual images

Phonological loop stores and rehearses speech-based information and is necessary for the acquisition of both native and second-language vocabulary.

Executive

Visuospatial Sketchpad

PhonologicalLoop

Long Term MemoryIt is referred to as a permanent storehouse

for information. Long term memory is capable of storing unlimited amounts of information. Anything that you want to remember for a long period of time must be transferred for short term to long term memory.

Baddeley’s Original Model of Working Memory

Visuospatial SketchpadCentral

ExecutivePhonological Loop

Baddeley’s Revised Model of Working Memory 2001

Baddeley’s Article

Central Executive

Visuospatial Sketchpad Episodic Buffer Phonological loop

Episodic LTMVisual Semantics Language

The Phonological LoopBroken into two components a phonological

store and an articulatory rehearsal system. It is assumed to decay over time unless refreshed by rehearsal, It is dependent on the second component the articulatory loop.

Phonological StoreSimilarity effect-the immediate recall of items

that sound similar (B ,V, G T, C,) is poorer than dissimilar items (F ,K ,Y, W, M,R ,)

Similarity of meaning has little effect in the standard immediate recall paradigm

The opposite is true for the learning of multitrial long term learning of ten items, it solely depends on semantic rather than acoustic

Articulatory RehearsalIt was proposed to give an account of the

immediate word length effect, whereby the is the immediate serial recall is a direct function of the length of items being retained (Baddeley, Thomson& Buchanan) An example is a sequence such as sum, pay, wit, bar, hop is much more likely to be recalled correctly than helicopter, university, television, alligator, opportunity. This reflects the slower rehearsal of longer words that allows greater forgetting.

The Visuospatial SketchpadAssumed to capable of temporarily maintaining and

manipulating visouspatial informationForms an interface between visual and spatial

information accessed either by senses or long term memory

Takes up one slot in working memory.Processed simultaneously, rather than sequentially.Drives retreival– conjoint retention model.

The Central ExecutiveIn charge of focusing attentionAlso in charge of dividing attentionSwitching attention also happens hereForms an interface between long term

memory and subsystemsResponsible for metacognitive monitoring.

Episodic BufferThis is assumed to be capable of combining

information from LTM with that from the slave systems.

Dedicated to linking information across domains to form integrated units of visual, spatial, and verbal information (e.g., the memory of a story or a movie scene, a 2D graphic).

Responsible for metacognitive strategy deployment.

SummaryBaddeley replaced the unitary short-term store

with a working memory system consisting of three components: an attention-like central executive, a phonological loop holding speech-based information, and a visuo-spatial sketchpad specialized for spatial and visual coding.

This working memory system is of relevance to non-memory activities such as comprehension and verbal reasoning. The phonological loop and visuo-spatial sketchpad have both been sub-divided into two-component systems, one component for storage and one for processing. The central executive fulfils several functions. Many of the characteristics of the central executive remain unclear.