Dual-coding theory

In developing this theory, Paivio used the idea that the formation of mental imagery aids learning through the picture superiority effect.

Not enough research has been done to determine if words and images are the only way we remember items, and the theory would not hold true if another form of codes were discovered.

[5] Another limitation of the dual-coding theory is that it is only valid for tests on which people are asked to focus on identifying how concepts are related.

While this limits the effectiveness of the dual-coding theory, it is still valid over a wide range of circumstances and can be used to improve memory.

Analogue codes retain the main perceptual features of whatever is being represented, so the images we form in our minds are highly similar to the physical stimuli.

[4] Working memory as proposed by Alan Baddeley includes a two-part processing system with a visuospatial sketchpad and a phonological loop which essentially maps to Paivio's theory.

Paivio's work has implications for literacy, visual mnemonics, idea generation, HPT, human factors, interface design, as well as the development of educational materials among others.

First, functional magnetic resonance imaging (fMRI) is used to measure cerebral blood flow, which allows researchers to identify the amount of glucose and oxygen being consumed by a specific part of the brain, with an increase in blood flow providing a measure of brain activity.

Second, an event-related potential (ERP) can be used to show the amount of electrical brain activity that is occurring due to a particular stimulus.

Researchers have used both methods to determine which areas of the brain are active with different stimuli, and results have supported the dual-coding theory.

Other research has been done with positron emission tomography (PET) scans and fMRI to show that participants had improved memory for spoken words and sentences when paired with an image, imagined or real.

Those participants also showed an increase in brain activation that processes abstract words not easily paired with an image.

John Anderson and Gordon Bower proposed an alternative method – the propositional theory – of how knowledge is mentally represented.