The human brain is a powerful natural information processor – one that man has been trying hard to emulate in the field of robotics. The brain is the chip through which sensory impulses from the external world are processed and stored. The amazing part of the information processing in humans is that processing is unique for every individual and depends on the nature and complexity of the data as perceived by the individual.
The flow of information from the moment it is obtained as a sensory input data from the external environment to the way the brain processes the sensory stimuli can be studied in the following phases: sensing, perceiving, temporary storage in working memory, storage in long term memory through rehearsal and storage in long term memory through semantic encoding. A person’s response to any event relevant to the stored information takes place through search, retrieval and response.In a nutshell, the information processing takes place in the following steps: a person receives sensory data through his sensory organs such as eyes, ears, nose, skin and tongue. Once the information is sensed, selective perception takes place within a sensory register. The information is then stored temporarily in the working memory for less than a second in the form of auditory or visual data.
Once the information is subject to rehearsal, semantic encoding takes place and ultimately the information is stored in long term memory for future use (Gagne, 1996).The sensory input data obtained from the external environment are received by human sensor or receptors. The perceived data is then converted into neural information (Gagne, 1965). The neural information is carried by the nerves to the brain’s sensory register. In a fraction of a second, a determination is made to accept or reject the information.
This is the time taken for pattern recognition and selective perception to occur. Pattern recognition refers to the process whereby all sensory input is analysed and compared with previous stored data.These patters may be in the form of shapes, colors, sounds or textures. During the process of selective perception an individual filters the information stream and takes only what is relevant to him. One of the most vital activities in the act of information processing is this process of selective perception. When someone suddenly holds your hand, your reaction depends on who is touching you for what reason.
It might be a nurse wanting to take your pulse, it might be a friend wanting to grab your attention or a strange person with unknown motive.The impact of a perceived stimulus depends on other concurrent stimuli, recent and distant events, and current motivations and goals. Thus, we find that selective perception is a complicated process. Consider the case of optical illusions where different people see different patterns or objects from the same picture. According to Surprenant “An engineer can measure what’s out there, but that doesn’t mean that that’s what a person will perceive,….
Humans use previous experiences, knowledge, and biases—as opposed to data alone—to perceive the world” (Purdue, 2007).Selective perception is the output of attention which is an internal cognitive process that helps in processing information from internal sources such as memory and reflection. Sometimes, there is a need for selective attention when there is a large amount of chaotic sensory overload. For example, while you are talking to your friends, you can still hear someone in next table calling your name.
Attention is accompanied by perception, cognition, memory and response.Barry Stein's laboratory at Wake Forest University in the United States found that the shape of a right angle drawn on the hand of a chimpanzee starts the visual part of the brain working, even when the shape has not been seen. It has also been proved by scientists the senses of smell and taste chemically combine to give us flavor. Perception is a tangled web of processes and so much of what a person sees, hears and touches is determined by his or her own expectations that it is difficult to know whether two people can perceive in a similar manner.Once the information passes through the sensory filter, it enters working memory.
This is the crucible in which the sensory input stays for a while to allow conscious thought to observe it. Existing information from long term memory storage also helps to interpret it. If it were a phone number that is given as sensory input, through rehearsal, the number is encoded, and chunked up for storage purposes. Thus the working memory prepares information for transfer to Long Term Memory through semantic coding. The long term memory can be compared to a hard drive on a computer.
When the information is stored in an organized manner it can be easily retrieved (Brannon, 2007). Its like keeping books in a library shelf. By keeping the chemistry books in the chemistry cupboard, it would be possible to retrieve it easily in the library. Likewise, semantic coding allows systematic organized storage of information. Semantic coding can happen in the form of tree structures or paragraphs or in the form of pictures. There is evidence that long term memory is permanent and no information can be lost.
However, in real life, we find that stored information becomes ‘forgotten’ or lost after some time.This is because the stored information has become inaccessible due to clashes between old and new memories. For memory recall to be totally effective, it is necessary to know how it was encoded and stored. The advantage of long-term memory is that there is no limit to the information that can be stored and there is no need for constant rehearsal.
There are three difference types of long-term memory: procedural memory helps in remembering how to do particular tasks such as changing the tire of a car; semantic memory that includes knowledge about the world, concepts, facts, language and vocabulary.Semantic memory stores information in networks that can be built gradually with new information. Episodic memory stores events and that is how we are able to remember every Christmas that passes by – who we were with on that day, what we ate, how we played games, etc. The Information Processing Model helps us understand how every person gets to perceive the same things in life in a different manner and remember things differently depending on the nature of information storage.
