(part 6 of 6)
We have considered visual and auditory sensation and perception now. Next week we will think about higher mental functions, or cognition. I would like to introduce one of the fundamental models of how human cognition proceeds before that. This is the Human Information Processing Model.
Central tenet of human information processing theory is that human performance is driven by a series of processing stages. Stage 1 requires that the information from the environment is coded in some form of internal representation. In Stage 2, the internal version of the stimulus is compared with memorised representations that are stored in the brain. Stage 3 is responsible for translating the encoded stimuli from the previous stage to a response code. When an appropriate match is made the output is passed onto Stage 4 that deals with the organisation of the response and the necessary action. The model assumes that information is unidirectional, and each stage takes a certain amount of time (generally thought to be dependent on the complexity of the operations performed). Each stage can only proceed following the successful completion of the previous stage.
Of course, the idea that there are stages and a series of boxes is simplistic. We need to look at different aspects of the cognitive system in relation to different needs and different task requirements. Thus, tasks are analysed not in terms of the amount of information processed per se for the various stages, but in terms of how new information entering the system is dealt with. These include things like how information is organised and classified, how relevant stored information is retrieved to make sense of it, what decisions are made and how this information is stored. We will address some of this when we consider learning, memory, and problem solving.
It is worth noting that this model is very much a child of the age of computers, being an input-output model of human cognitive processing. Information goes in, is processed and an output is generated. Within this model, information "in the head" is of paramount importance. Many simplistic views of this model assume the model entails that we represent information internally in a very detailed way. This view has been called "representationalist" and has been heavily criticised. However, whilst more extreme versions of this model do suffer from over representationalism, I believe that this model is not wholly incompatible with the more "situated" views which suggest that information is also "in the world". This suggests that we use cues and stores in the world for information storage. Technology changes the nature of those cues and stores. An example would be a diary. If I don't have a diary then I probably need to remember things. If I have a diary and a routine for checking it every morning, I don't need to remember the event list itself, but I do need to remember to look at my diary. This is arguably is easier to remember as a routine than as a constantly changing list of things to do. The diary has changed what I need to remember.
For further information on perception, see
Anderson, J. R. (1996). Cognitive psychology and its implications (3rd ed.). New York, NY: W. H. Freeman.
Boff, K. R., & Lincoln, J. E. (1988). Engineering data compendium: Human perception and performance. Wright-Patterson Air Force Base, OH: Harry G. Armstrong Aerospace Medical Research Labratory. This is a series of 3 books that attempt to organize what we know into a coherent theory. It fails, but is quite useful.
Sekuler, R., & Blake, R. (1985). Perception. New York, NY: Alfred A. Knopf.