Evaluate two models or theories of one cognitive process with reference to research studies
The cognitive process we are going to examine is memory and compare two models.
Model 1: The multi-store model of memory (Atkinson and Shiffrin, 1968)
This model was one of the first to give an overview of the basic structure or architecture of memory and it was inspired by computer science. The model seems rather simplistic, but it did spark off the idea of humans as information processors and it has been one of the most influential models attempting to describe the memory system.
The multi-store model is based on the assumption that memory consists of a number of separate stores (sensory, short-term and long term) and that memory processes are sequential.
Sensory memory registers sensory information and stores it for around 1–4 seconds. Information in the sensory memory is modality specific (i.e. related to different senses). Only a small amount of the sensory information will be transferred into the short-term memory (STM) store (depending on whether or not it is attended to).
STM has limited capacity (around seven items) and limited duration (around 6–12 seconds). Information processed in STM is transferred into LTM if it is rehearsed. If not, it is lost.
LTM is believed to be of indefinite duration and of potentially unlimited capacity.
Evidence of the multi-store model of memory: the serial position effect:
· The serial position effect is believed to be linked to rehearsal, i.e. people repeat things in order to remember. The serial position effect suggests that people remember things better if they are either the first (primacy effect) or last (recency effect) item in a list of things to remember.
Study to use: Glanzer and Cunitz (1966)
Evidence of the multi-store model of memory: case studies of individuals with amnesia due to brain damage
Amnesia is caused by damage to the hippocampus and related networks involved in storage of new memories.
MRI scans shows that H.M. had severe damage to the hippocampus which is critical in the storage of information into LTM.
H.M. could store new procedural memories (implicit memory) but he was not able to store new explicit memories (semantic or episodic). This shows that the memory system contains different systems.
Strengths of the multi-store model of memory:
The model pioneered the new approach to memory where humans are seen as information processors.
The model’s conceptualization of memory as multi-stores is supported by research.
It has been possible to make predictions based on the model and to design experiments.
The overall model has been modified, for example by Baddeley and Hitch (1974) with their new version of short-term memory, the “working memory” model.
Limitations of the multi-store model of memory:
The model is very simplistic and it cannot account for how interaction between the different stores takes place (e.g. how information from LTM may indicate what is important and relevant to pay attention to in sensory memory).
Research into the encoding of LTM has challenged the single-store version of LTM. It is now accepted that LTM contains several stores (e.g. semantic, episodic, procedural).
Model 2: The working memory model (Baddeley and Hitch, 1974)
· Baddeley and Hitch suggested the working memory model as an alternative to STM.
· This model challenged the view that STM is unitary and that information processing is passive. So it replaced STM with Working Memory.
· Working memory is seen as an active store used to hold and manipulate information. The model has been developed over the years to include findings from research (e.g. a fourth component, the episodic buffer, has been added).
Working memory includes three separate components:
The central executive: A controlling system that monitors and coordinates the operations of the other components (slave systems). The central executive is modality free so it can process information in any sensory modality but it has limited capacity.
The phonological loop handles verbal and auditory information. It is divided into two components:
1. The articulatory control system: the “inner voice”.
2. The phonological store: the “inner ear”. This can hold speech-based material active in a phonological form. It is assumed that a memory trace can only last from 1.5 to 2 seconds if it is not refreshed by the articulatory control system.
The visuo-spatial sketchpad: the “inner eye”. This handles visual and spatial information from either sensory memory (visual information) or from LTM (images).
Study to use: Quinn and McConnel (1996)
Strengths of working memory:
· The model has been useful in understanding which parts of the memory system may be linked to underlying problems in reading and mathematical skills.
· The model focuses on the processes of integrating information, rather than on the isolation of the subsystems. This provides a much better basis for understanding the more complex aspects of executive control in working memory.
Limitations of working memory:
· The major criticism of the first models of working memory was the unclear role of the central executive.
· The model has been criticized for its emphasis on structure rather than processing (encoding, storage or retrieval).