Brain Function

It will be helpful to take a quick look at how the brain processes information from the environment before we consider the specific implications of how the environment affects learning.

David Sousa (2001) and Patricia Wolfe (2001) explain in detail how the brain takes in information from the environment and processes it. The graphic below and what follows is a summary of their explanation.

Our brains take in huge amounts of information from the environment daily. Think of all the sounds, sights, smells, tastes, and sensations that are taking place around you at any given moment. The information is registered by our five senses. Our brain screens all of this data through the sensory register, represented by the window in the graphic, to determine what is important based on our need for survival and our past experiences. Most of the data is deemed unimportant and is filtered out and dropped from attention and processing. Imagine if our brains actually processed all of the activity happening around us. We would simply be overwhelmed. The sensory register passes on data that is considered important to the immediate memory, sometimes called short-term memory, pictured by the door.

To understand this better, picture yourself sitting in a crowded subway or bus. You don't look at each person thinking that you will need to recognize them should you meet them again. But if suddenly a familiar face appears, the sensory register determines from past experience that this is important information and passes it on to the immediate memory, represented by the door, which opens to begin processing the data.

PRIORITIZING INFORMATION PROCESSING
Now the brain makes a decision about how to handle the data. Responses to the data are processed in hierarchical order. If the brain perceives threat, other data processing takes on a lower priority so that the brain may deal effectively with the threat. If that familiar face in the subway belongs to a persistent stalker (allowing our imaginations to run a bit wild here), our brains tell us to take action to protect ourselves, since survival is a top priority of the brain.

Or, to look at a more familiar situation, take our perception of sound as an example. As we sit listening to a lecture, there is usually background noise in our environment which our brains decide not to process because it is deemed unimportant. Our listening focus is on what the teacher is saying. But should there be a loud siren or unfamiliar noise, the attention quickly shifts from the lecture to the loud noise, especially if some type of threat is perceived. At that point, it would be difficult for us to recall what the teacher had just said (and it might even be difficult for the teacher to recall what he or she just said, too). In addition, the perception of threat causes a fight of flight response with physical changes in the body: glands release cortisol throughout the body which can result in depression of the immune system, tensing of the large muscles, blood-clotting, and increased blood pressure. Stress, which could be defined as an on-going perception of threat, causes the same reactions in the brain and body. Over time, these physical reactions can increase one's susceptibility to illness. Any time we experience a sense of danger, whether physical, environmental, academic or emotional, our bodies and brains react with this fight/flight syndrome. So data involving threat receives the highest priority for processing in the brain.

Emotional data receives the second highest priority for processing in short term memory. Emotions can quickly take overrational processing. Most of us have had experiences with extreme anger at one time or another. Obviously, one cannot reason with an overwrought individual. Sousa says, "When an individual responds emotionally to a situation, the older limbic system (stimulated by the amygdala) takes a major role and the complex cerebral processes are suspended." (p. 42) Conscious rational processing shuts down during highly charged emotional events. However,, emotions are not entirely bad when it comes to memory. Events that associated with strong emotions, whether good or bad, are usually easily recalled. Aromas, food, songs can all trigger powerful emotional memories. Because emotions are linked to past experiences, new experiences that are similar evoke the same emotional response. In Teaching with the Brain in Mind, Eric Jensen (1998) points out that the brain is overstimulated when strong emotions are present. Emotions give us a more activated and chemically stimulated brain, which then helps us recall things better. Emotions can either enhance learning or inhibit learning. According to Sousa, "How a person 'feels' about a learning situation determines the amount of attention devoted to it. Emotions interact with reason to support or inhibit learning. To be successful learners and productive citizens, we need to know how to use our emotions intelligently." p. (43)

CONSCIOUS DATA PROCESSING
The next stage in processing information from our surroundings occurs in working memory, represented by the gear. This is where consciousprocessing takes place, whereas the previous processing of data was unconscious. Information in working memory receives our attention. However, we are unable to process much data in working memory. Adults generally have the capacity to work with five to nine pieces of data at any one time. Sousa provides us with a good example of how working memory functions.(p. 45) Try it by clicking on First Number below. Look at the number you see there for seven seconds and then turn away and write the number on a piece of paper: First number

Now check and see if you got the number right. Try it again with the second number: Second number

You probably found that you could remember the first number quite easily, but that you weren't as successful with the second number. Because the second number had 10 digits, most people do not have enough working memory capacity to process that many pieces of data. However, through a process called chunking, we can make it easier to remember a lengthier series of numbers. Try one more time to see how you do remembering this number: Third number

This number is the same as the second number, but it has been chunked into the familiar pattern of a telephone number. This makes it easier to remember all ten digits.

In Peter Russell's study done in 1979, (as cited in Sousa, 2000) it was determined that adults are generally able to retain information in working memory for ten to twenty minutes before boredom or fatigue cause the brain to loose focus. In order to continue dealing with the same data, it's necessary to change the way the person is dealing with the data.

INFORMATION STORAGE
The final stage in information processing is moving information into long-term storage, represented by the chest of drawers. Information that is not moved into long-term storage is forgotten and can never be recalled. We've all had the experience of talking about an event in the past. Others seem to remember things about which we have absolutely no memory. Those particular things did not move into our long-term storage and, as far as we are concerned, never happened. Again the brain prioritizes data to be stored. Information that has value for survival is quickly stored, while emotional experiences also facilitate the storage and recall of information. Next in priority is information that seems important because of past experiences. In particular, the data must make sense, and more importantly, it must be meaningful in light of past experiences to be moved into long term storage. Emotions and past experiences make the connection between what we consider relevant and what we remember. For example, contrast your experience memorizing a random list of words and remembering what you had for dinner last night. It will be much easier to remember what you had for dinner because it is more personally relevant. This has enormous implications for learning. The section on Constructing Meaning will be concerned with this aspect of brain functioning. Information must be meaningful to be retained. Click here to go to this section of our model.

The process of moving information into long term storage usually occurs during deep sleep. Most newly acquired information is lost within 18 to 24 hours. If new information cannot be recalled 24 hours later, it is quite likely that it has not been stored and can never be recalled. When a memory is placed in long-term storage, physical and chemical changes actually occur in the brain. New neural pathways are formed and existing pathways are strengthened. Sousa states that our capacity to store information is limitless: we have about 100 billion neurons, each of which has thousands of dendrites, which form neural pathways between the neurons.

In the process of encoding information in long-term storage, the memories are broken into components and stored throughout the brain. One can also say that memories are "filed" in different ways. Memories can be classified in two ways: nondeclarative and declarative. Nondeclarative memory, sometimes called implicit memory, includes procedural memory, motor skill memory and emotional memory. Procedural memory consists of things like typing, riding a bicycle or tying a shoelace. They are performed without conscious thought or attention once the procedure has been learned. Motor skill memory involves many of the things we do every day: our morning grooming and breakfast rituals, driving to work. How many times have you arrived at work in the morning, only to realize you don't really remember driving to work, as if you were on automatic pilot. Emotional memory is often called "flashbulb memory" because emotionally laden events are easily retrieved. Examples include the Challenger disaster or the assassination of JFK. Declarative memory, also called conscious or explicit memory, on the other hand, involves the recall of facts. In educational settings, we are most concerned with declarative memory. There are two types of declarative memory: episodic memory and semantic memory. Episodic memories are connected with events that occurred in our lives at a specific time and place. Semantic memory deals with facts and information not directly linked to events in our lives. Episodic memory is retained more easily than semantic memory. With practice and review, the connections between the neurons become stronger and stronger and the information is more easily recalled. Again, this has enormous implications for the way we present information to our students.

The square drawn around the chest of drawers in the graphic at the top of this page represents our cognitive belief system. All of the information that is in our long term storage determines how we perceive the world around us. The combined information helps us understand what is happening around us, helps us make decisions, and determines our values. Within this belief system are beliefs about ourselves, our self concept. If the sum of an individual's past experiences is positive, that person will have positive beliefs about himself. Or if the sum of the experiences is negative, the individual will have a low self esteem. People who have frequently experienced failure tend to block incoming data with a potential for failure right at the sensory register stage of processing, closing off receptivity to new information.

Thus, it appears that the end stage of brain processing, that of developing a belief system and a sense of self, is influential in determining what happens at the very beginning of the process. The implications of this process on learning and teaching are indeed significant. Since the beginning point of the process is the reception of input from the environment, changes in the environment can have a very really affect on learning potential. So let's look more carefully at the environment in our classrooms.

BRAIN FUNCTION