Memory
About 2000 years ago, before books, knowledge was retained by memorizing information. One's ability to remember information was synonymous with one's intellectual prowess. Consequently, elaborate techniques to memorize vast amounts of information evolved. Remembering was an art, encoding information to be remembered into visually elaborate detailed stories with emotional associations attached to meaningful personal experiences. These mental movies created a journey of experiences that included engaging activities in a highly vivid visual sequence of events in one mind's eye, connecting each mental event to the topics to be remembered. This technique was called building a Memory Palace and is used by the mental masters of today. (described by Joshua Foer) These ancient techniques illustrate the fundamental elements of the memory process. We remember what we give our attention to. We remember what we experience through our senses. We remember what we are engage in. We remember what is meaningful and relevant to us.
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Our memories are the building blocks of our thinking and learning. They are the framework for our very existence holding the pieces of lives. What we remember and what we know defines who we are. Knowing and remembering allows one to understand. The ability to recall and manipulate, shuffle, reorganize, and recreate, is higher order thinking. Memory is a highly complex multifaceted system involving many areas and functions of the brain working together. Our memories are formed through a series of stages. The way memories are made; stored, recalled, and processed is the foundation of cognition. It is our memories that create the highly sophisticated way we are able to relate to our environment, the global community; a long way from eat or be eaten. We continue to evolve.
A memory is made in stages; sensory, immediate, short term, working and long-term memory. Memories begin as a deluge of experiences streaming in through our senses. Our sensory memory screens this plethora of sensory stimuli. In a millisecond, this information is sifted by its importance, related to survival, at the brain stem in the RAS (reticular activation system) and thalamus. Emotions strengthen memories and increase their importance. Fear and anxiety cause a reflexive response that inhibits cognitive functioning when hormones are released.
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Immediate memory and short-term memory are temporary and unconscious. Immediate memory holds information for just 30 seconds, and then drops irrelevant data. With further attention, information is sent to short-term memory. The prefrontal cortex is active during this stage of processing. Small amounts of information are held ready and active for seconds to a minute. Information can stay in short term memory for longer periods if it is reintroduced, through rehearsal, or repetition.
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Working memory is temporary and processes information on a conscious level. Two separate neural circuits are thought to keep information alive in working memory; the phonological loop that encodes audio signals and the visuospatial sketchpad that encodes visual and spatial information. The flow in and around these two systems is controlled by the central control system in the prefrontal cortex.
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Working memory cannot attend well to both audio and visual input at the same time. Working memory has specific limitations involving time and quantity. Pre- adolescents can spend 5-10 minutes processing in working memory with sharp focus and 10-20 minutes is considered average for adolescents and adults. Fatigue and lack of focus will occur beyond these limits unless there is a change or break in the manner the information is being addressed. Working memory can organize and manipulate data from short-term memory as well as data from long-term storage, but can only handle a few items at once. Working memory can juggle an average of five items for ages 5-14 and an average of seven items for adults, but this capacity can be improve by chunking information together in ways that give meaning.
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Longterm memory can store large amounts of information for a lifetime. Information worth holding onto breaks out of working memory and travels to the hippocampus where it is encoded permanently through a process called long term potentiation and sent to sensory associated areas in the brain. The more ways information is encoded, the greater the number of memory pathways. This is why presenting information in a variety of ways, involving many of the senses is so effective. It is like learning many different routes to the same location. In addition, when new learning is associated with the senses, recall pathways are strengthened.
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Memories are stored with associated pre-existing experiences after attention given, making sense of, and giving meaning to the memory. A memory is consolidated when the neural firing pattern is played back and forth often between the hippocampus and the cortex. This repetition causes the memory to move permanently to the cortex, freeing up space for new memories in the hippocampus. Consolidation mostly occurs during sleep.
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When a memory is recalled the hippocampus is able to retrieve information from sensory associations and is able to put the parts together as a whole, reconstructing the original experience accompanied with senses and emotions. When recalling an experience, neurons fire in the same pattern that they fired when the experience was encoded, thus reconstructing the episode. Retrieval is the re-creation of a past experiences by the synchronous firing of neurons that were involved in the original experience
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creating an electrical pathway. When this same memory is recalled repeatedly, the neurons become more strongly connected. Their firing pattern is sensitized, pre-set, and ready to go. If one neuron in the pattern is stimulated and fires, the other neurons will automatically fire the pattern, like a set of dominoes. The memory pathway becomes "hard wired," recalling more quickly and efficiently.
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An event in the present can also stimulate recall of information to be used to guide a decision or action. When a memory is retrieved, it is integrated into the new information causing a slight change to the memory.
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Creative Thinking
Recent studies by Sharon Thompson - Schiller, a neuroscientist at the University of Pennsylvania, have shown that creative thinking occurs under unique conditions. Normally the pre frontal cortex is engaged in focused, rule guided cognitive activity. However, this area acts very differently in a creative mental state when novel ideas are generated. There is a lower state of cognitive control in the prefrontal cortex during the creative mental state when generating novel ideas. In this state, rules and assumption do not "box in" our thinking. It was discovered that the prefrontal cortex became electrically "quiet" when the subject thought with fewer restrictions and was in a state of "blurred" attentional focus. Thompson- Shillers team gave this state a name, they called it
hypofrontality
.
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This kind of thinking is very different from the mental state of cognitive control and focused thinking involving ridged perimeters, guidelines, and assumptions as when analyzing or evaluating. Additional studies in the 90's supported this hypothesis when brain waves were measured over the prefrontal cortex. While participants generated novel ideas, alpha waves (8 to 12 cycles per second EEG waves) were recorded. The synchronized firing of the neurons in the state of defused attention and relaxed wakefulness is a state of lower cognitive control. Alpha waves denote a synchronized firing of the neurons. Further support for the theory of
"hypofrontality"
was found during the generation of novel ideas, in Schiller-Thompsons most recent study. In this study, participants were asked to find uses for objects. The most creative participants showed minimal activity in their prefrontal cortex but also showed activity in the posterior brain regions, areas of visuospatial skills.
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These studies suggest that when there is lower cognitive control, thus less filtering of knowledge, one is able to think more creatively. The state of hypofrontality allows one to be more open to possibilities without preconceived notions and assumptions that could stifle thought. The characteristics of the mental state needed to generate novel ideas and facilitate creative thinking is a state that is relaxed, with less cognitive control, and defused attention. However, the mental state needed to become the subject area expert necessary before entering the creative domain requires a mental state of focused attention with cognitive control.
The ability to move back and forth between these cognitive states, from a mental state with high cognitive control to a relaxed state of diffused attention of lower cognitive control, is called cognitive flexibility. In a 2010 study by Zabelia and Robinson, it was discovered that the more creative thinkers showed greater cognitive flexibility when measuring results of the Stroop test, a test that measures cognitive control using color words written in same and different colors than their name.
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Creative thinking is our highest cognitive domain. It is the thinking that generates novel ideas and innovations. Creative thinking requires a unique mental state, hypofrontality, a relaxed state with defused attention, and less cognitive control. In addition, the generation of creative ideas and solutions is best accomplished alone, but after it is generated, sharing the idea with others can help develop it. Once a creative idea is generated, however, putting it into action and developing it requires a more controlled, focused cognitive state as needed for assessing and evaluating.
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Breaking through old thinking styles requires one to exercise cognitive flexibility, an ability to move fluidly between mental states as needed. I believe this skill is worth sharing with our student and structuring learning for this opportunity. With this understanding, students will learn to exercise cognitive flexibility, adapting as necessary to the needs of a particular problem, stretching their mental limits propelling them forward, as thinkers, innovators, and creators.
