Kosslyn Computational Model

Kosslyn’s model goes and meets Paivio’s model in many ways. According to Kosslyn, our mind possessess two permanent information storages: images and propositions.

Via the images storage you will find information about the object’s form (through images) and through the propositional one, you’ll find the object’s meaning. These two types of representation are separated, however, they must join up in order for us to be able to represent the object in our minds.

For Kosslyn, images are represented in a spacial medium, with a limited capacity. It provides us the ability to deal with spatial relationships and object rotation, but the information depends on some perspectives.

For example, in a 1975 study, Kosslyn asked the subjects to imagine a rabbit and an elephant. Then, he asked them to imagine a rabbit and a fly. The rabbit had way more details in the second condition, because it’s the larger animal and our representation acts accordingly to that fact.

Two levels of image representation

According to Kosslyn, the image representation has two components, a superficial representation and a deep one.

The deeper representation is the stored information in Long-term Memory, from which the superficial representations branch out. These ones happen at visual level in the active memory.

In deep representation, the images could be subdivided in literal or perceptive appearance of the object and the list of propositions describing the object.

In conclusion, looking at a practical example: an image of the country’s president implies both the existence of an image and a proposition, in this case the presidency.


Paivio’s theory of dual coding

According Paivio’s theory, people use two systems of Mental Representation. They are independent from each other, yet connected. They are the verbal system and the non-verbal system and this is the basic assumption of Dual Coding Theory.

Each one of these systems has different types of information. Paivio defended that the non-verbal system deals with images and its equivalents in other sensory organs, while the verbal system dealt with the language processing. But, as I stated above, theses two systems are connected and each and any concept is associated to other concepts, in both systems, at the same time.

In 1971, a memory test was made in order to support this theory and provide some answers about this dual coding system. A long list of words and photos was given to the test subjects for memorizing. The results were unanimous: the subjects always recalled more photos than words.

In order to understand these results, some comparisons and analysis were required. First off, it was necessary to compare the verbalizable photographs with the non-verbalizable ones, as well as, the words that were more or less imagetic.

The differences between the subjects who were told to build a mental image for any presented word and the ones who were not instructed in that way were also analyzed.


General Conclusions

Cognitive performance is mediated by two interrelated systems which are different in structure, organization and information representation. In the verbal system (logogens) the information is represented in an abstract, logical and sequential manner, while in the non-verbal system, the representation is made through images in a concrete and analogical manner.


Coding Redundancy

Paivio studies’ show that the mnesic performance increases directly with the quantity of alternative codes in memory, which means, that if you can make the subject memorize a piece of information in the two systems of representation, the probability of him recalling it increases.

Although, these studies also show that if you give the test subject the information in a single code and ask him to create a second one, it will interfere with his memory capacity, which hypothesizes that sometimes, dual coding some sort of information can just be redundant.


Some modern neurocognitive studies support this theory.

What is Imagery?

A concept born with Aristotle, imagery can be defined imagery as an internal ability to represent images. However, in truth, imagery is much more than that. It’s a way of thinking which involves your senses in your thought process. It’s the ability of creating an image in your mind that you can see, hear, feel, smell or taste.


It’s an implicit system of codification that you use as an instrument in order to recover information about physical properties and relationships among different objects.

There are several different areas of investigation in regards to imagery. Scientists have long been focused on: imagery as a material’s property or attribute, as a cognitive process, as a personal experience (due to the fact that the vivacity of the internal images differs from person to person) and even imagery as a mental representation.

You need former experiences to produce internal images from external stimuli and those will allow you to describe the object or place. Maybe even allow you to describe a more complex scene that you’re seeing in your mind.

But, since we’re talking about something so subjective, the data must of course be obtained through verbal reports from the study subjects.

This whole concept of imagery includes two types of representation: analogical and propositional. In analogical representation we’re talking about the perception, or in other words, the image that arrives at your retina with all of its sensory qualities. The propositional representation however, includes no perception, being the images’ descriptions of the different visual scenes.