Human Information Processing System DR. NEIL H. SCHWARTZ PSY 353 Internal Cognitive Environme nt Long Term Store Short Term Sto re Encoding Retrieval Sensory Register External Environment Sensory Register Purpose Capacity ~On ave. about 500 msec (1/2 second). ~No difference between 5 year olds & adults at 50 msec. ~By 100 msec differences between children and adults emerge and widen up to 1,000 msec (1 sec). The difference is explained by children’s and adult’s gradually increasing ability to move stimuli into Short term store by applying: attention and strategies Short Term Store Purpose We apply strategies (control processes) to encode and retrieve information. Capacity 7 +/2 and 30 seconds "All the interesting developmental action is in the short term store." A Closer Look at Short Term Memory The study of short-term memory has revealed several things about what it is children can do with their memory, and how they are different, and in some ways the same as adults. When digits are used memory span looks different for different ages: 2 year olds = 2 5 year olds = 4 7 year olds = 5 9 year olds = 6 So, maturational differences in CAPACITY are small, as children get older. But, maturational differences in SPEED of processing are much more substantial. Thus, children get faster at processing as they get older. Speed of processing accounts best for age differences in memory span-- both the speed at which a child can identify something as known to them and the speed at which the child can articulate those items. Thus, short term memory gets faster and more efficient for children when items become more familiar to them and they can use their language better to say things faster. In fact, when a child (or adult) has some prior knowledge of material to be remembered, processing is much much faster. Using the Short term Store Internal Cognitive Environment There is a distinction we need to make about the short term store….. Sometimes, it is referred to as… Working Memory Long Term Store Short Term Store Encoding Retrieval Sensory Register External Environment Short term memory is sometimes called working memory. But, the two need to be distinguished from one another. Short-term memory refers to the capacity of this part of the memory system to hold things without any use of controlled processes (like strategies or special attention) Working memory refers to a person's conscious effort to act on information in the STM store-- to transform it,by applying special attention and using strategies to hold it there longer and get it into long-term memory STM versus Working Memory There is little difference among children and adults in terms of short-term memory capacity, but there is considerable difference between children as they get older (and children and adults) in their capacity to use their STM-- that is, differences in working memory. A child's speed and efficiency of processing is accounted for by differences with which a child can use his or her working memory. Let’s take a closer look at speed and efficiency of Processing... Speed of Processing 1. Older children have more processing resources available to them for executing cognitive operations than do younger children. Thus, young children need more time and use up more working memory space to process information (either to remember it, or reason with, or solve problems with it, etc.). This means young children have to "think"more and are slower when trying to remember things or solve problems. Speed of Processing 2. As children get older, they have more experience with things making some information more familiar than others. The more familiar information, the faster it is processed. Thus, older children are faster at processing most information because they are either more familiar with it or they can use familiar related information they already have, to help them process new unfamiliar information. Speed of Processing 3. As children get older they get faster at processing information because their neurological system matures. a. They have more links between neurons, and thus more neural pathways to use to link familiar information with new information. b. Their neurons are gradually becoming more myelinated so they transmit electrochemical impulses faster. Thus, the more information exposure children have the more dendritic links neurons make between each other, and the faster children can process information. Differences in the memory of children is not only accounted for by speed, but also accounted for by the efficiency with which the children can process information. Efficiency of Processing 1. Children, as they get older, use less mental effort to process things cognitively because they get more adept at applying and using strategies to acquire information. Thus, speed increases because children get practiced in knowing which strategies are easiest to use and which ones are most helpful. Efficiency of Processing 2. Case, in a theory of memory, made a distinction between storage space and operating space-- the same one we made earlier today between STM and Working Memory He said that…. Storage Space + Operating Space = Total Processing Space Storage space is the mental space a person has available for storing information. Operating space is the mental space a person has available to use for executing operations (that is, processing). The point is… As children get older they process information more efficiently because strategies are practiced and become mastered, requiring less operating space, and producing more storage space. More storage space means a person can hold more things in mind to be able to process them. More things makes thinking capacity potentially more complex , more elaborate, and richer. We have been talking about cognitive processing-- the speed of processing and the efficiency of processing. But, just what is "processing"? Processing is the use of strategies people employ to understand, remember and solve problems. …..Next, we will take a look at cognitive strategies……. Cognitive Strategies Defined Cognitive strategies = are goal directed operations used to aid task performance. They are deliberately implemented and potentially available to consciousness. They are often controlled processes, that over time and use become automated. Examples of strategies are: 1) rehearsal, 2) organization, 3)chunking, 4) imagery, 5) self-checking or self-monitoring(a metacognitive strategy). Cognitive Strategies continued There are strategies for reading, arithmetic, fixing a bike or a car, getting someone to like you, explaining things to people so they understand. Can you describe a strategy you have for something? The Development of Cognitive Strategy Use Children develop in their use of strategies, but in an interesting way. Take a look at the following three items….. 1. At first, children, when they are young, show what is called a mediational deficiency.a. A mediational deficiency is when a child does not spontaneously generate a strategy to help solve a task and doesn't make use of that are given to them. They don't have the mental capacity use them. 2. Then, children, as they get older, show what is called a production deficiency. a. A production deficiency is when a child, when given a strategy, will make use of the strategy, but will not spontaneously produce them. That is, they have the mental capacity to use a strategy, but do not produce them. 3. Finally, children, as they get older still, will both produce and use strategies on their own. The question is: What are the production deficient children doing? They are producing strategies, but just not very efficient or effective ones. And, sometimes, they are just downright primitive . For example, they will simply "try hard". They also show what is called a utilization deficiency. a. A utilization strategy refers to the fact that young children will be able to use strategies, whether primitive or not, sometimes as effectively as older kids, but will experience no benefit from them in performance. The question is: Why no benefit? The execution of a strategy requires heaps of mental effort; and, young children do not have enough information processing resources to execute the strategy and still perform other aspects of the task at hand. a. The condition is analogous to a computer without enough RAM to run itself and a program at the same time. b. Since strategies are effortful, young children just don't have the resources in their information processing systems to: (a) bring them up, (b) make use of them, and (c) do the steps of the task at hand, all at the same time. Older children do. Finally, some summary statements... 1. Strategy use takes effort. 2. Since young children process information less efficiently, it makes them less likely to use strategies spontaneously and to benefit from them if they do. 3. As children get older, they execute more strategies and use them with greater effectiveness, because their brains have matured and they can cognitively process more efficiently. 4. When older children use strategies, they: a. have multiple strategies available to them in their repertoire; b. these strategies compete with each other; c. early on in development, the easiest simplest strategies will win most of the time; d. later in development, with maturation and practice, children will use more effortful and efficient strategies, often in parallel (that is, together). 5. Part of the reason, strategy gets more efficient, is because: the amount of knowledge a person already has plays a strong role in how new information is processed.