WHAT IS LEARNING AND MEMORY?
Memories are the internal mental records that we maintain, which give us instant access to our personal past, complete with all of the facts that we know and the skills that we have cultivated. Encoding, storage and retrieval are the three primary stages of the human memory process. (Forgetting may constitute the fourth stage of memory, although forgetting is technically a setback in memory retrieval). During the encoding stage, information is sent to the brain, where it is dissected into its most significant composing elements. An ensemble of brain cells processes incoming stimuli and translates that information into a specialized neural code. In the storage phase of memory formation, the brain must retain encoded data over extended periods of time. Retrieval constitutes the right of entry into the infinite world of stored information, where we bring old information out of permanent memory back into working memory, which can be mentally manipulated for usage. Theoretically, learning is the capability of modifying information already stored in memory based on new input or experiences. Since memory is contingent upon prior learning, the first step in memory is learning, which occurs when our sensory systems send information to the brain. Our sensory system can hold numerous items simultaneously, but only momentarily. Learning is an active process that involves sensory input to the brain, which occurs automatically, and an ability to extract meaning from sensory input by paying attention to it long enough to reach working (short-term) memory, where consideration for transfer into permanent (long-term) memory takes place. Sensory information enters consciousness naturally in two subtypes, both of which are somewhat fleeting. Iconic memories of visual information have a duration of 0.3 seconds, while echoic memories of auditory information will last about four to five seconds. The brain shows more partiality to iconic information. (See “Visualization and Memory Lists”). Vision has a much longer history in the human experience than does the printed word. By exploiting this competency, students learn quickly when they can visualize the concept while studying, by directed use of the mind’s eye, where mental pictures can be developed. Writing words in the air on an imaginary blackboard forces students not only to visualize the order of letters in a word, but to maintain visually what they have already written in working memory as they continue to write. From first grade to medical school, this technique is equally effective. When young learners are taught to construct diagrams that show relationships (graphic organizers), their memory of content improves substantially. Robert Marzano found that these “nonlinguistic representations” can increase achievement scores by 27 percentile points. We constantly perceive vast amounts of information each minute, but we make no attempt to recall very much of it. Equally important, we cannot remember information that we failed to encode for memory storage in the first place. Once the elements that make up an experience are classified according to their special traits, each part is shunted to a different brain region for further detailed analysis, where a comparative search for recognizable similarities to previously encountered information begins. The various pieces of new information get stored in neural circuits distributed throughout the cerebral cortex. Because the elements making up a memory reside in multiple cortical areas, the stronger the network linking the associated pieces together, the more resistant to it will be to forgetting. As the brain transacts learning events, physical changes occur both within brain circuitry and in its structure-function correlations. Here the brain parts company with the popular comparisons to a digital video recorder. Memory is quite fluid, and, over time, the brain continues to revisit and reorganize stored information with each subsequent experience in a cyclical fashion, reprogramming its contents through a repetitive updating procedure known as brain plasticity. This is advantageous, since improvements are made repeatedly to existing data. Prior knowledge is revised based on new input, resulting in a more accurate representation of the current world, increasing one’s probability of thriving. The flip side of these constant memory revisions is that eyewitness accounts often become less reliable with the passage of time. With new experiences, we amend, rather than maintain and protect, our past memories—occasionally changing them beyond recognition. The newly stored information has been altered, forming new and modified representations of events and our malleable knowledge, which serve as our guides to the environment. When first exposed to a new song, we establish new neural connections—of the sounds, the emotional pleasure, where we heard this new song, the lyrics, the title, the artist, similar songs, etc.—to represent this novel sensory experience. However, upon hearing the same song on a second occasion, it is processed as a neurologically different experience, where established connections are re-activated as recognition. We now recall the song, which did not occur upon first exposure, sing along with now recognizable lyrics (also impossible during the initial exposure) and later reproduce the lyrics in the absence of any song being played. All new learning pathways are built from existing circuits and are accompanied by changes in brain physiology as a result of experience. Although academic language describes learning as the “acquisition of knowledge,” new information instead gets integrated into the complex web of existing data, rather than acquired and stored in isolation. Thus, integrating the curriculum enhances content retention when subject matter enjoys the benefit of multiple integrated connections. |