Information processing

Here we think of the mind as having just three main components: a sensory or data-input system, long-term storage and a central processing mechanism.

Figure 1.1: A simple three-component model of the mind

Data input
Our senses (visual, auditory, taste, touch and so on) all perform a similar function: they convert physical stimuli in the outside world (light, sound, etc) into signals travelling along chains of nerve cells (neurones). At the retina of the eye, for example, patterns of light and dark, of colour and of intensity are converted into electro-chemical signals which pass along the optic nerve to the brain. Those signals, by themselves, have no meaning; they need to be interpreted, to be given meaning.

Long-term memory
Our brains are capable of storing enormous amounts of information for very long periods, often for a lifetime. We have some idea of how memory works — by groups of neurones developing easy associative pathways between them, so that when one is ‘fired’ the others are also activated. Apparent failures of memory are often not because a trace has been lost, but because there is some temporary problem in retrieving the data.

Working memory
In this information-processing model, the central processor is known as ‘working memory’ which is not particularly useful as a description. Think of it as a space into which go signals from the senses where they are inspected (as it were) and compared with what is known already from long-term memory. This process enables the mind to give meaning to incoming sensory signals — for example, to recognise an object as a coffee mug, the sound of a word as the name of a loved one and so on.
Working memory has three important features that control the quality of thinking:
1 It is very fast-acting. Signals go in and out of it very quickly and are probably not retained for longer than three seconds at most.
2 It has a very limited capacity. Even mature, intelligent adults can probably not hold more than about seven bits of information in working memory at one time. This has serious implications for the power of thinking.
3 Its capacity develops slowly with age. Less able children aged 4 in Reception may only be able to handle one bit of information at a time, average Year 1 pupils maybe two bits, and even by Year 6, a typical 11-year-old will be restricted to some four pieces of information which they can work with at one time.
So how do these three components of the mind work together? As a teacher, you may be giving instructions to your pupils either as a group or individually. The string of words you produce impinges on the children’s ear drums where they are sensed and converted into a string of electro-chemical signals running along neurones (nerve cells). Working memory receives this string of signals and searches long-term memory in order to identify what that particular pattern of signals means. If working memory succeeds in making sense of the signals, then there is a chance that the child will be able to act on the instruction.
But things can go wrong with this process at a number of different stages.

• First, the child’s attention may be distracted by something interesting a friend is doing, something happening outside the window, or something exciting seen on television the night before. In this case the mind simply fails to pay attention or even to try to make sense of what you are saying.
• But even if the child is genuinely paying attention, maybe something you say simply does not correspond with anything in his or her experience. There is inadequate previous knowledge stored in long-term memory and so the child fails to make meaning of, and fails to understand, what is being asked.
• A third possible source of failure of the mind’s processing mechanism is overload of working memory.

You know that young children have difficulty following a series of instructions. It just becomes impossible to hold in mind too many instructions at the same time because of the limitations of working memory capacity.
The implications of the first two of these possible reasons for failure of comprehension are pretty clear: try as far as possible to ensure that you have the child’s undivided attention and try to check that what you are saying is not so completely novel that it has no meaning. In this book we are going to focus mostly on the third possible reason for incomprehension, the limitations imposed by working memory capacity. We will offer a series of strategies for (a) stimulating the growth of working memory capacity and (b) making the most efficient use of what working memory capacity is available.

These are central to the process of improving children’s general thinking capabilities.


Lets Think Handbook Copyright © by Alex Black. All Rights Reserved.

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