Types of Associative Memory Models

Types of Associative Memory Models

There is a number of Associative Memory Model available in the Neural Network.

Like:    Taylor (1956)

Steinbuch(1961)

Anderson (1968)

Gabor (1969)

            Kohonen(1971)

Nakano & Nagumo(1971)

Gardner-Medwin(1976)

But Hopfield Network (1982) and Associative or Willshaw Network (1969) are more popular and have impact on Neural Network and based on Habbian Learning.

What is Hopfield Network?

It is single layer network and fully Recurrent and Auto- associative network but can be Binary (1, 0) or bipolar (1,-1).

It can reconstruct the data after being fed with incomplete or corrupt version of input data, and this model work on pattern recognition. It follows unsupervised learning as, we do not provide any training data, and it simply recognises the patterns in the data set.

What is Associative Net (1969)?

Associative network is Hetero-associative in nature. It is Feed-forward (usually) and origin in theoretical biology

The capacity can be analyse using information theory approach (much information the neuron’s response can communicate)

What is Hebbian Network and Theory?

In the study of neural networks in cognitive function, it is often regarded as the neuronal basis of unsupervised learning. Hebbian theory concerns how neurons might connect themselves to become engrams or Hebbian Network.

During the learning process, Hebbian theory that proposes an explanation for the adaptation of neurons in the brain,

It explains the mechanism for synaptic plasticity, where an increase in synaptic effectiveness arises from the pre-synaptic cells repeated and resolute the stimulation of the postsynaptic cell.

Let’s assume that, the continuation of a re-vibratory activity tends to induce lasting cellular changes that add to its stability.

When an axon of cell “A” reaches at threshold potential to excite a cell “B” and repeatedly takes part in firing it, some metabolic change takes place in one or both cells such that A's efficiency, as one of the cells firing B, is increased.

“Cells that fire together, wire together”.

Hebb's theories on the form and function of cell assemblies can be understood from the following:”

The general idea is an old one, that any two cells that are repeatedly active at the same time will tend to become 'associated',

When one cell repeatedly assists in firing another, the axon of the first cell develops synaptic knobs (or enlarges them if they already exist) in contact with the soma of the second cell

The theory attempts, in which simultaneous activation of cells leads to pronounced increases in synaptic strength between those cells, and provides a biological basis for errorless learning methods for education and memory rehabilitation