If all the data received by our senses were stored in our memory, we would soon be overwhelmed. The subconscious sorts through the input and retains only a fraction for permanent memory storage. Every second, the eyes absorb ten million bits of information, the skin takes in one million bits, and the ears receive one-hundred thousand bits. Of these millions of bits processed, only about forty bits reach the conscious mind. Data that are not deleted are sorted and filtered by the subconscious, then consigned to long-term memory.
The active brain can remember things that actually did not happen or that are not correct. The mind makes assumptions to link events. People remember words that are implicit or not stated, with the same probability as explicit words. Studies with fMRI have demonstrated that the same brain areas are activated during questions and answers about both true and false events. This may explain why false memories can seem so compelling to the individual reporting the events.
Types of Memory
Remembering – storing memories in a memory bank, and recalling them – is a biological process which involves dedicated brain structures as memory banks variously specialized for different types or categories of memory function. Knowing that memories are formed in different categories, and that they move between categories, can help in developing strategies for improving memory and learning.
There are two broad categories of memory: non-conscious, and conscious. The latter includes short-term, and long-term memory.
- Non-conscious memory, takes two forms. One of these, implicit memory, automatically stores experience and concepts and plays a role unconsciously in affecting perception. The other form, muscle memory, plays a role in the mechanical execution of a series of motions, as in riding a bike or playing a musical instrument, learned through repetition over time.
- Short-term memory, is the working memory. It’s a place for stuff that you need to hang on to for only a short time. Maintaining information for only a few seconds, it enables you to remember a current thought, and so, for instance, take part in a conversation, keep a lecture in context as it progresses, or maintain the thread of a story or movie.
- Long-term or permanent memory: The memory of the events and facts that we can consciously recall and verbally describe. It includes that of words, symbols, and general knowledge about our perception of the workings of the world. Information of a personal nature, things witnessed or experienced, is better remembered when associated with emotion.
The brain links information on an unconscious level. You can consciously help to maximize this effect. As you perceive new input, match it as best possible to material already in your memory, by using images, sounds, key words, and concept maps. A vital ingredient for memory is reviewing, and it is effective only when done at specific times after absorbing the information. For instance after one hour, one day, one week, and six months.
The Emotional and Thinking Brains
This is a good juncture to explain the difference between different types of stress. Unhealthy stress is either too low or too high. Healthy stress is often just called a challenge. Frequently, the distinction is conditional on how much control we perceive that we have over the stressor. In challenging situations, the body releases chemicals such as adrenaline and norepinephrine. These enhance learning by increasing motivation, sharpening our perceptions, and even strengthening our body. On the other hand, unhealthy stress raises alarms all over the body by releasing cortisol, the survival hormone. In this book, I use the word stress to refer to unhealthy stress.
Neuroscientist Joseph LeDoux discovered a particular relationship and interaction between the emotional and thinking brains, and identified the neural pathways that carry information from the senses to the brain. Information entering through the eyes or ears goes first to the thalamus, which acts as a sorting area to assign different information to different parts of the brain. It compares new data with existing information and decides whether to compress, absorb, or ignore the new input. If the incoming information is emotional, the thalamus sends out two signals. With survival a priority concern, the first signal goes to the emotional brain (limbic system, specifically, the amygdala), and the second to the thinking brain (neocortex). This means that the emotional brain has the information first and, in the event of an emergency, can react before the thinking brain has even received the information and had an opportunity to consider options.
In such a case, the amygdala sends instructions to the lower reptilian brain to flood the body with stress hormones. There are more neural connections going from the limbic emotional center to the neocortex than vice versa. With continued arousal of the amygdala, it is difficult to break out of the resulting fight or flight cycle. So reason does not rule, and we are left hanging in the middle of a crisis.
The hippocampus helps create long-term memory by assigning data to different parts of the brain. For example, the names of natural things such as vegetation and wildlife are stored in one part of the brain, while man-made items such as cars and furniture are retained elsewhere. Likewise, the event, or what happened, and its meaning are laid down in separate parts of the brain.
Emotion drives attention which, in turn, drives memory. James McGaugh, PhD, of the University of California at Irvine, said, “We believe that the brain takes advantage of the chemicals released during stress and powerful emotions to regulate the strength of storage of the memory.” Journalist Jill Neimark said, “A memory associated with emotionally charged information gets seared into the brain.”
It is the management of emotions that gives learners greater command over their learning.
Although the brain thrives on challenge and complexity, its primary drive is survival. It needs to survive socially, economically, emotionally, and physically. The brain is pre-wired to learn and, if optimum conditions are not present, employees may learn to fear change in the workplace, and students may learn to fear subjects like math. Overwhelming stress has a detrimental effect. Researchers have evidence that high stress experienced by a pregnant woman can distress the fetus, resulting in learning difficulties for the child later in life. Among infants and toddlers, high and chronic levels of stress can make learning more difficult, perhaps even shrinking the part of the brain associated with memory.
Tips to Remembering
Imagine that I recite a list to you of thirty items. I then ask you to write them down after I finish. You would remember things that are:
- at the beginning of the list
- repeated, repeated
- at the end of the list
The first and last items are known as primacy and recency. Every study session has them. If you study for one hour, then take a break, you get one of each. If you study for twenty-five minutes, take a short break, then study another twenty-five minutes. You get double the primacy and recency events. How great is that?
Memory is not stored in a single location in the brain. It is deconstructed and distributed all over the cortex. The emotional content is stored in the amygdala, visual images in the occipital lobes, memory of the source in the frontal lobes, and venue is stored in the parietal lobes. Remembering is actually an act of reconstruction.
Memory Decay, or loss of remembered events, is a natural phenomenon as new experiences displace existing memories. You can easily counteract this loss of learned material through periodic review. Review can facilitate the preservation of at least 80 percent of your learned material. Without a systematic review process, the material evaporates to a 20 percent retention level.
A greater variety of input streams from eyes, ears, tactile, and emotion allow for more pathways to exist for dynamic reconstruction, thus creating richer memory. Multi-modal instruction makes a lot of sense. Accelerated Learning addresses the need.
To get a handle on just how unlimited our ability to learn is, multiply the number of neurons (10 billion) by the number of branch spines (10 million) by the number of dendrite spiny protuberances possible on each spine (100 million). The result indicates how many new connections are possible when learning. Using this size font, the answer is a 1 followed by zeros that extend for some 6.2 million miles!
The capacity of our memory is virtually unlimited.