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January 23, 2018 | Author: Anonymous | Category: Science, Health Science, Neurology
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Schemas are cognitive structures (mental templates or frames) that represent a person’s knowledge about objects, people or situations. The concept of schema was first used by Jean Piaget in 1926 and later developed by Frederic Bartlett (1932). Schemas are used to organize our knowledge, to assist recall, to guide our behavior, to predict likely happenings, and to help us make sense of current experiences. They simplify reality.





They come from prior experience and knowledge. They allows us to take short-cuts in interpreting vast amounts of Information. For example, we may have “schemas” for a good teacher and bad teacher. When we see behavior similar to our schema of a good teacher we may then label the teacher as a good teacher.







Experience can also change schemas. For example, when you were younger, you may have thought that a “good teacher” was someone who gave little to no work and had a relatively “easy” class. Your schema for a “good teacher” may now be someone who prepares you for college and or helps you to understand the material.







As previously stated, humans integrate new information with existing, stored information. Schema theory therefore states that what we already know will influence the outcome of information processing. In other words new information is processed in the light of existing schema. Thus, schemas then can affect our cognitive processes.





While the use of schema theory to learn in most situations occurs automatically or with little effort, sometimes an existing schema can actually hinder the learning of new information. Prejudice is one example of schema that prevents people from seeing the world as it really is and inhibits them from taking in new information. By holding certain beliefs about a particular group of people, this existing schema may cause people to interpret situations incorrectly. How can a prejudice cause a misinterpretation of things we view in the world?



When an event happens that challenges these existing beliefs, people may come up with alternative explanations that uphold and support their existing schema instead of adapting or changing their beliefs.







If you have already stored schema that urban teenage males are aggressive and you meet a pleasant urban male teen, your memory of him may be affected. If you were surprised with his politeness, you may remember him as even more polite than he is. Or, you may not even notice how polite he was because you were expecting him to be rude, and so you remember him as the typical urban teen you had previously imagined in your mind.







Support for the influence of schemas on cognitive processes is widespread. Bartlett (1932) demonstrated how schema, specifically cultural schema, can influence memory in his classic study. He gave participants a complex and unusual story called ‘The War of the Ghosts' which contained unfamiliar supernatural concepts and an odd, causal structure to Western participants. He purposefully did this so the information would not fit into their preexisting schemas.







He asked them to recall it six or seven times over various retention intervals. He found that recalled stories were distorted and altered in various ways making it more conventional and acceptable to their own cultural perspective. He used the term rationalization to refer to this type of error - rationalizing it according to what fitted with their existing cultural schemas - for example canoe was often substituted for 'boat'.





There is a lot of research to support the idea that schemas affect cognitive processes such as memory (Barlett, Loftus, etc.). This theory seems quite useful for understanding how people categorize information, interpret stories and make inferences. Schema theory has also contributed to our understanding how cognition develops in children (Piaget) and also how memories can become distorted. Furthermore, social psychologists often refer to 'social schemas when they are trying to explain stereotyping and prejudice.



Schema theory helps to understand cultural and gender differences, since different genders & cultures may have different schemas which influence the way they interpret the world.



However, there are some methodological flaws with the research, for example, Bartletts' choice of material meant that the stories he chose may not have been meaningful to other people, but he had no objective measure of 'meaningfulness'.





It is an important to note that much of the research can be criticized for having low ecological validity. Cohen (1993) states that schema theory is rather vague and the theory fails to offer detailed explanations of how the schemas are acquired in the first place. Cohen believes the theory is overly simplistic (reductionist) and does not account for complexity of human cognition.



However, recent biological research by Caramazza (2009) found that from the visual cortex, information about living and non-living objects are shuttled to different parts of the brain as to trigger appropriate reactions—even in blind participants—so some schemas appear to be connected to localized areas of the brain.

Bibliography:  Bartlett, F.C. (1932). Remembering: A Study in Experimental and Social Psychology. Cambridge University Press.  Fanz, R. L. (1961). Maturation of Pattern Vision in Infants During First 6 Months. Scientific American, 204: 66  Piaget, J. (1926). The Child's Conception of the World. Towota, NJ. Littlefield Adams.

According to the second principle of the cognitive level of analysis:  Models of mental processes can be proposed and investigated scientifically Research have looked at models for various cognitive processes:  Decision Making (availability heuristics, representative heuristics, etc.)  Language (rote-memory model, abilities model, critical age model)  Learning (social-learning, classical conditioning, etc.)







Mental models have been studied by cognitive scientists as part of efforts to understand how humans know, perceive, make decisions, and construct behavior in a variety of environments. The term “mental model” has been used in many contexts and for many purposes. It was first mentioned by Craik in his 1943 book, The Nature of Explanation. (Craik, 1943). These mental models help us to investigate cognitive processes scientifically in order understand how these processes interact, operate, and change with biological and sociocultural factors.





While several different models of memory have been proposed, the multi-store memory model of memory is often used to explain the basic structure and function of memory. Initially proposed in 1968 by Atkinson and Shiffrin, this theory outlines three separate stages of memory: sensory memory, short-term memory and long-term memory.





This model is based on two fundamental assumption: 1) memory can be conceived of as a few discrete "structures"; 2) information passes through these structures in a systematic order. Information is originally encountered via the sensory system and is retained for a very short period of time in sensory memory (sort of like a "buffer").

As soon as we attend to the information it is transferred to short term memory, which is working memory, conscious awareness. The capacity of short term memory is quite small relative to long term memory, according to this model.







Sensory Memory Sensory memory is the earliest stage of memory. During this stage, sensory information from the environment is stored for a very brief period of time, generally for no longer than a halfsecond for visual information and 3 or 4 seconds for auditory information. We attend to only certain aspects of this sensory memory, allowing some of this information to pass into the next stage - shortterm memory



Most “strangers” that we see on an everyday basis, according to this model, usually do not make it past sensory memory unless something significant is attached to the person.

Jeffrey Beard



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Short-term memory, also known as active memory, is the information we are currently aware of or thinking about. In Freudian psychology, this memory would be referred to as the conscious memory. Paying attention to sensory memories generates the information in short-term memory. Most of the information stored in active memory will be kept for approximately 20 to 30 seconds. While many of our short-term memories are quickly forgotten, attending to this information allows it to continue on the next stage - long-term memory.







Long-term memory refers to the continuing storage of information. In Freudian psychology, long-term memory would be called the preconscious and unconscious. This information is largely outside of our awareness, but can be called into working memory to be used when needed. Some of this information is fairly easy to recall, while other memories are much more difficult to access. Example: 12358. This number was possibly in your long term memory until a “cue” called it into your working memory.





Laid a foundation for advancements in mental modeling. The multi store model of memory was one of the first models of memory to provide a logical account of the structures and processes that make up memory. It has been an influential model and has lead to the development of other more sophisticated theories such as the working memory model.

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Has been supported by research. Multiple research studies support the assumption of a structural model for memory. For example, research by Sperling (1960) showed support for the capacity and duration of sensory memory being different to that of short term memory. The research by Sperling demonstrated that we can access more than 9 bits of information if we try and access them quickly enough from sensory memory but if this is left longer than 1 second this access fades away (as with the example of the picture of Jeffrey Beard).

Contemporary limitations  Nowadays most cognitive psychologists argue that multi store model provides a limited and simplistic explanation of memory processed.  For example the levels of processing approach demonstrates that information is not transferred to long term memory simply by rehearsal but involves more sophisticated processing.  The model also can not explain why we often clearly remember highly emotional events. Such as flashbulb memories.





Case studies of brain damaged participants such as Clive Wearing also show that the Multistore Model is an oversimplification of how memory actually works. Clive was similar to H.M. in that he could not remember new information for more than a few seconds; however, he could learn new skills.







This suggests that there is a separate long term memory for skills (Procedural Memory). Clive could also remember facts about his life prior to the illness, but could not remember any experiences. This meant that he repeatedly had revelations that he was conscious for the first time. This suggests that there are separate long term memory stores for facts (semantic memory) and experiences (episodic memory).





Although the model itself makes real world sense, the research is mostly experimental and thus lacks ecological validity. For example, they lack real world relevance in the way they often use word lists which are not a valid indication of how we actually learn and recall things in everyday life.





The levels of processing model of memory (Craik and Lockhart, 1972) was put forward partly as a result of the criticism leveled at the multi-store model. Instead of concentrating on the stores/structures involved (i.e. short term, long term memory), this theory concentrates on the processes involved in memory.

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Unlike the multi-store model it is a nonstructured approach. The basic idea is that memory is really just what happens as a result of processing information. Psychologists Craik and Lockhart proposed that memory is “just a by-product of the depth of processing of information and there is no clear distinction between short term memory and long term memory.” Depth, in other words, is how we extract meaning from the stimuli.

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The greater the processing of information during learning, the more it will be retained and remembered.

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Shallow Processing The

crucial assumption of this levels of processing theory is that retention of an item is dependent on the depth or level of processing carried out the material. Superficial processing leads only to shallow, temporary Retention (which explains why we don’t recall physical details of strangers unless we find significance in the stranger); deep processing leads to efficient, durable retention.

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Shallow Processing This takes two forms  1. Structural processing (appearance) which is when we encode only the physical qualities of something. E.g. the typeface of a word or how the letters look.  2. Phonemic processing – which is when we encode its sound.  Shallow processing only involves maintenance rehearsal (repetition to help us hold something in the STM) and leads to fairly short-term retention of information. This is the only type of rehearsal to take place within the multi-store model.

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Deep Processing  3. Semantic processing, which happens when we encode the meaning of a word and relate it to similar words with similar meaning. Deep processing involves elaboration rehearsal which involves a more meaningful analysis (e.g. images, thinking, associations etc.) of information and leads to better recall. For example, giving words a meaning or linking them with previous knowledge.

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This explanation of memory is useful in everyday life because it highlights the way in which elaboration, which requires deeper processing of information, can aid memory.

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Reworking – putting information in your own words or talking about it with someone else. Method of loci – when trying to remember a list of items, linking each with a familiar place or route. Imagery – by creating an image of something you want to remember, you elaborate on it and encode it visually (i.e. a mind map).

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The theory is an improvement on Atkinson & Shiffrin’s account of transfer from STM to LTM. The levels of processing model changed the direction of memory research. It showed that encoding was not a simple, straightforward process. This widened the focus from seeing long-term memory as a simple storage unit to seeing it as a complex processing system.

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Craik and Lockhart's ideas led to hundreds of experiments, most of which confirmed the superiority of 'deep' semantic processing for remembering information. It explains why we remember some things much better and for much longer than others. This explanation of memory is useful in everyday life because it highlights the way in which elaboration, which requires deeper processing of information, can aid memory.

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Despite these strengths, there are a number of criticisms of the levels of processing theory: It does not explain how the deeper processing results in better memories. Deeper processing takes more effort than shallow processing and it could be this, rather than the depth of processing that makes it more likely people will remember something.

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The concept of depth is vague and cannot be observed. Therefore, it cannot be objectively measured.

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What do we already know about the relationship between physiology and cognition that can help us to answer this question?

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This means that anytime you are thinking, the brain is working. In other words….everything psychological has a physiological origin.

With this assumption, damage to the physical brain , imbalances in neurotransmission and hormones, genetic mutations, food & drug intake, sleep deprivation, and other biological factors can all impact cognitive processes.





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Hippocampus damage and amnesia (i.e. Clive Wearing and deficits in memory). Low Dopamine Levels and deficits in multiple cognitive functions. Sex Hormonal Levels and cognitive decline. Sleep deprivation negatively impacting our mood, our ability to focus, and our ability to access higher-level cognitive functions





The earliest scientific evidence of a link between sleep and performance dates back to the early 1930’s, when Nathaniel Kleitman, one of most significant figures in the field of sleep medicine, discovered a daily pattern in the speed and accuracy of cognitive performance. He showed that even in well-rested individuals there was a decrease in the level of individual performance that occurred in the early morning and again late at night.









Thus, even when we are getting the amount of sleep we need, we can still expect normal fluctuations in our ability to function. Many students study “early in the morning” or “late at night”. From this research, how can this impact your cognitive performance? Epinephrine, an excitatory neurotransmitter, is naturally at lower levels in the morning and late at night. Low levels have been can result in lack of focus, and low levels of motivation. This is why we often feel less motivated in the morning time.







In addition to these normal fluctuations, not getting enough sleep—whether for just one night or over the course of days to weeks—has a significant effects on our ability to function. Sleep deprivation negatively impacts our mood, our ability to focus, and our ability to access higher-level cognitive functions. The combination of these factors is what we generally refer to as cognitive performance. In the laboratory, researchers use scientific studies to determine just how significantly varying levels of sleep disturbance impact various types of cognitive processes.







In addition to these normal fluctuations, not getting enough sleep—whether for just one night or over the course of days to weeks—has a significant effects on our ability to function. Sleep deprivation negatively impacts our mood, our ability to focus, and our ability to access higher-level cognitive functions. The combination of these factors is what we generally refer to as cognitive performance. In the laboratory, researchers use scientific studies to determine just how significantly varying levels of sleep disturbance impact various types of cognitive processes.





In addition to the feeling of mental fatigue and changes in brain activity that accompany a night without sleep, other measures of performance are noticeably altered. Concentration, working memory, mathematical capacity, and logical reasoning are all aspects of cognitive function compromised by sleep deprivation.





However, not all of these functions rely on the same regions of the brain, nor are they impacted by sleep deprivation to the same degree. For example, the region of the brain known as the prefrontal cortex (PFC) is responsible for many higher-level cognitive functions and is particularly vulnerable to a lack of sleep. As a result, people who are sleep deprived will begin to show deficits in many tasks that require logical reasoning or complex thought.





However, not all of these functions rely on the same regions of the brain, nor are they impacted by sleep deprivation to the same degree. For example, the region of the brain known as the prefrontal cortex (PFC) is responsible for many higher-level cognitive functions and is particularly vulnerable to a lack of sleep. As a result, people who are sleep deprived will begin to show deficits in many tasks that require logical reasoning or complex thought.



Research suggest that a loss of REM, or rapid eye movement sleep (a period of intense sleep ) can result in increased irritability (correlated with lower norepinephrine levels) anxiety and depression (correlated with lower serotonin levels), decreased socialization, reduced concentration and decreased ability to handle complex tasks (due to low levels of PEA) and to be creative (due to lower dopamine levels).



Research suggest that a loss of REM, or rapid eye movement sleep (a period of intense sleep ) can result in increased irritability (correlated with lower norepinephrine levels) anxiety and depression (correlated with lower serotonin levels), decreased socialization, reduced concentration and decreased ability to handle complex tasks (due to low levels of PEA) and to be creative (due to lower dopamine levels).



Determining just how much performance is affected by sleep loss is difficult, in part because of factors such as individual differences in sensitivity to sleep deprivation, as well as individual differences in motivation to stay alert despite sleep loss. Even so, the evidence is clear that a lack of sleep leads to poor performance.





Research suggests that the nerve connections that make our memories are strengthened during sleep. ‘ “Sleep embeds the things that we have learned and experienced over the course of the day into our short-term memory,” says Avelino Verceles, MD, assistant professor at the University of Maryland School of Medicine and director of the school’s sleep medicine fellowship.







It appears that different phases of sleep play different roles in consolidating new information into memories. If your sleep is cut short or disrupted, it interferes with these cycles. When you’re sleepy, you may forget and misplace things often. The inability to focus and concentrate caused by sleepiness further weakens memory. “If you’re not able to concentrate on what’s at hand, it’s not going to make it into your short-term memory and then long-term memory,” says Allison T. Siebern, PhD, a Fellow in the Insomnia and Behavioral Sleep Medicine Program at the Stanford University Sleep Medicine Center.

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