mercoledì 2 gennaio 2013

Come la memoria sviluppa l'apprendimento.

edyourdon-memoryTeachers are the caretakers of the development of students’ highest brain during the years of its most extensive changes. As such, they have the privilege and opportunity to influence the quality and quantity of neuronal and connective pathways so all children leave school with their brains optimized for future success.

 
This introduction to the basics of the neuroscience of learning includes information that should be included in all teacher education programs. It is intentionally brief such that it can be taught in a single day of instruction. Ideally there would be additional opportunities for future teachers to pursue further inquiry into the science of how the brain learns, retrieves, and applies information.
Teaching Grows Brain Cells
IQ is not fixed at birth and brain development and intelligence are “plastic” in that internal and environmental stimuli constantly change the structure and function of neurons and their connections. Teachers have the opportunity to help all children build their brains beyond what was previously believed to be fixed limits based on learning disabilities or the predictions of test scores or achievements.
It was once believed that brain cell growth stops after age twenty. We now know that through neuroplasticity, interneuron connections (dendrites, synapses, and myelin coating) continue to be pruned or constructed in response to learning and experiences throughout our lives.
These physical changes of brain self-reconstruction in response to experiences including sensory input, emotions, conscious and unconscious thoughts are so responsive that human potential for increased knowledge, physical skills, and “talent” in the arts is essentially limitless. There are conditions associated with the most successful strengthening of neural networks, such as guided instruction and practice with frequent corrective feedback. As neuroscience research continues more information will be available to guide teachers providing the brain with the experiences best suited to maximize its learning and proficiency.
High Stress Restricts Brain Processing to the Survival State
The prefrontal cortex, where the higher thinking processes of executive functions (judgment, critical analysis, prioritizing) is also the CEO that can manage and control our emotions. Like the rest of the PFC it is still undergoing maturation throughout the school years. Students do not have the adult brain’s developed circuits of reflection, judgment, and gratification delay to overcome the lower brain’s strong influence.
Neuroimaging research reveals that a structure in the emotion sensitive limbic system is a switching-station that determines which part of the brain will receive input and determine response output. Brain-based research has demonstrated that new information cannot pass through the amygdala (part of the limbic system) to enter the frontal lobe if the amygdala is in the state of high metabolism or overactivity provoked by anxiety. It is important for teachers to know that when stress cuts off flow to and from the PFC, behavior is involuntary. It is not students’ choice in the reactive state when they “act out” and “zone out”.
Through interventions to go beyond differentiation to individualization (see article about video game model) it is possible to decrease the stressors of frustration from work perceived as too difficult or boredom from repeated instruction after mastery is achieved. Further information from neuroscience research reveals other causes of the high stress state in school and suggests interventions to reduce the stress blocking response in the amygdala.
Memory is Constructed and Stored by Patterning
The brain turns data from the senses into learned information in the hippocampus. This encoding process requires activation or prior knowledge with a similar “pattern” to physically link with the new input if a short-term memory is to be constructed. The neuroimaging research supported by cognitive testing reveals that the most successful construction of working (short-term) memory takes place when there has been activation of the brain’s related prior knowledge before new information is taught.
When teachers work to clearly demonstrate the patterns, connections, and relationships that exist between new and old learning (e.g. cross-curricular studies, graphic organizers, spiraled curriculum) the probability of encoding increases.
Teachers can help students increase working memory efficiency through a variety of interventions correlated with neuroimaging responses. For example, with opportunities to make predictions, receive timely feedback, and reflect on those experiences. These experiences appear to be increase executive function facilitation of working memory, such as guiding the selection of the most important information hold in working memory.
Memory is Sustained by Use
Once and encoded short-term memory is constructed it still needs to be activated multiple times and ideally in response to a variety of prompts for neuroplasticity to increase its durability. Each time students participate in any endeavor, a certain number of neurons are activated.  When they repeat the action, the same neurons respond again.  The more times they repeat an action, the more dendrites grow and interconnect, resulting in greater memory storage and recall efficiency.
Retention is further promoted when new memories are connected to other stored memories based on commonalities, such as similarities/differences, especially when students use graphic organizers and derive their own connections. Multisensory instruction, practice, and review promote memory storage in multiple regions of the cortex, based on the type of sensory input by which they were learned and practiced. These are distant storage centers are linked to each other such that triggering one sensory memory activates the others.  This duplication results of storage increases the efficiency of subsequent retrieval as a variety of cues prompt activation of different access points to the extended memory map.
The construction of concept memory networks requires opportunities for students to transfer learning beyond the contexts in which it is learned and practiced. When information learned and stored in its own isolated circuit it is only accessible by the same stimuli through which it was obtained. These transfer activities activate memories to new stimuli and with other knowledge to solve novel problems. These simultaneous activations promote extended connections among memories that are the larger concept memory networks most applicable to future use.
Pattern recognition facilitation and opportunities for knowledge transfer extends the brain’s processing efficiency for greater access to and application of its accumulated learning. These teaching interventions will prepare graduates for future incorporation and extension of new information as it is becomes available. Students who have the guided learning experiences needed to construct concept memory networks will be have the best preparation for their futures. As the information pool expands, these students will continue to comprehend new information, consolidate it into their neural networks, and recognize, develop, and globally disseminate its new applications.
The Future
As the research continues to build, it will be the obligation of those who prepare our future teachers to insure they understand and can apply the best current and future teaching strategies. This includes insuring that the teachers who graduate from their programs have the foundational neuroscience knowledge to use the fruits of the expanding pool of research to the betterment of all their own future students. That is a fascinating and exciting challenge to meet at a pivotal time in the evolution of education.
scritto da: Dr. Judy Willis Phd in Education.