The HumanNervous System

Neuroscience Talks to Teachers 2

Last time we talked about observable changes in today’s students, changes that I believe are significant, not just trends. After the first post I talked with several teachers, each of which spoke about programs they are using to limit student phone time, and the positive outcomes of those programs. We recognize and agree that innovative changes are needed, and innovation is by nature disruptive, often controversial. My goal was to provide some neuroscientific background for understanding student behavior. Screen time addiction is one of those behaviors, as is aggression, creativity, and communication. Science traditionally tends to think of behavior as overt, observable behaviors. To be scientifically studied, behavior needs to be operationally defined as a set of observable behaviors. As our observational methods become more sophisticated, we can infer internal behaviors, covert behaviors, as a set of observable patterns of behaviors. For example, we infer thinking and reasoning from a pattern of responses on tests and other observations. We can infer emotions, feelings, imagination, and consciousness from observing carefully defined patterns of brain activity and behavior. Brain imaging provides some of these data. Studies looking at brain injury and developmental deficits, using imaging and genetic analyses are another example. Neuroscience is acquiring the methods and language to talk about our covert lives, our students’ covert lives.

Let’s establish a framework for talking about student behavior from the perspective of neuroscience. Let’s look at some neuroanatomy and physiology to get a better understanding of the human brain and how it affects emotion, memory, thinking and behavior. Learning about and teaching your students about the brain offers an opportunity for them to understand their behavior in a context. We see a biological source of our behavior and emotions, and we can be more mindful of it, and bring it increasingly under self-control. Understanding the development of the nervous system, and how the timing of stimulation affects the brain can help you customize your teaching to fit your students’ age range, and address some of the challenges we all face.

Looking down onto the top of a brain, you immediately notice that it has two very similar, if not identical halves, called the cerebral hemispheres. One side of the brain is responsible for the other side of the body. To put it clinically, the hemispheres have contralateral control of the body. You can also notice a deep fissure roughly dividing each hemisphere into a front and back half. That deep groove is called the Central Sulcus. That sulcus (Latin for “furrow”) marks the division between two of the brain’s main functions, moving our bodies, called motor behavior, and sensing the environment, called sensory behavior. Cortex in front (ventral) of the central sulcus is motor cortex. Cortex behind it (dorsal) is sensory cortex.

Let’s back up and talk about neurons for moment. The brain is an organ and like other organs of the body, it is made of cells. Some of those cells as you know are called neurons. They provide the communication networks that allow all our nervous system driven behaviors; seeing, hearing, moving around, eating, sex, dreams, imagination, thoughts, and emotions, to name a few. Neurons are supported in this effort by other cell types including glial cells, some of which produce the fat called myelin which coats and insulates several nerves.

Neurons have a cell body (soma in Greek) and cellular projections called dendrites, which carry information to the cell body, and axons, which propagate information away from the cell body. A resting neuron has a small negative charge because there are more negatively charged ions inside the cell than there are outside the cell. Charged particles like sodium and potassium move back and forth across the cell membrane and change the charge of the neuron. This electric charge, measured in millivolts, is sent down the axon where it will trigger the release of neurotransmitters, the brain chemicals influencing our behavior. Those neurotransmitters float across the synapse, which is a gap between neurons, and bind to receptors on the receiving end. The chemical structure of the neurotransmitter and the type of receptor it binds to determine if that chemical signal excites or inhibits the next neuron. For example, dopamine can bind to type 1 receptors and type 2 receptors (and other types). Docking with a type 1 receptor will increase dopamine release in the next neuron (excitation), and docking with type 2 receptors will inhibit dopamine release from the next cell. It gets complicated fast, creating incredible processing power for the brain. Later we will talk more about the different neurotransmitters and their effects on our behavior, and your students’ behavior.

Let me break down more neuroanatomy and how you can use that knowledge to create learning activities or enhance ones you already use. I’ll include some suggested activities below.

The nervous system is divided into the central nervous system and the peripheral nervous system. The central nervous system does most of the processing and decision making, while the peripheral nervous system collects and registers sensory data and stimulates muscles to contract. The central nervous system is the brain, which consists of the two hemispheres we just discussed, the brainstem, hanging down from the brain, the cerebellum, hanging off the back of the brainstem, and the spinal cord exiting the skull and running down the center of the vertebral column. The peripheral nervous system is the cranial nerves, the spinal nerves, and the hundreds of named and unnamed nerves going to and from the skin, muscles, organs, blood vessels, and bones.

Now let’s get back to that motor/sensory division of labor in the brain. The frontal lobes execute functions that prepare us to do something, such as planning, problem solving, and decision making. The frontal lobes also incite our muscles to move, creating behavior such as walking, talking, and riding a bike. The slowly developing prefrontal cortex is involved in impulse control and emotional regulation. That maturation process continues into adulthood and has profound implications for education and student success. The frontal lobe has distinctly dark areas that control language production (Broca’s Area). Somewhere around the age of seven, children have internalized their private speech and increasingly use it for thinking and to regulate their behavior. Activities like journaling and meditation can promote this development. Teaching the brain sets the stage for creating these activities.

Behind that central sulcus are the parietal lobes on top, and the occipital lobes in the very back. The temporal lobes, behind your temples, are on the lateral aspect of the hemisphere. We will break down the functions of these lobes, along with the rest of the nervous system as we move along.

Having students learn some fundamentals of human biology can help them understand their own behavior and bring it under increasing self-control. It teaches us how we can be so alike we are, and yet so unique.

Some suggested teaching activities related to neurons and the frontal lobe:

1. Elementary students
   1. Show students a diagram of the brain and show them the lobes of the brain and their function. Draw their attention to the frontal lobe and go over the main functions, giving them examples from their own behavior when you can. Make sure to cover talking, planning and thinking, making decisions, controlling the muscles (movement), and controlling our actions and emotions.
   1. Hand our diagrams and have them color the frontal lobes. Have the write down one function. Ask them to volunteer good decisions and plans they have made recently. Ask them why the frontal lobes are important.
   1. Create a story board where animals or characters have to make a decision, for example what to do with a found toy, or how to help a friend. Have them talk about how the frontal lobe contributes to these actions.
2. High School
   1. Create a presentation on the brain and the frontal lobe. Have students label diagrams with each lobe and one function. On the back, have students list several functions of the frontal lobe and examples from their lives (e.g., talking, decision making, planning, impulse control). Ask for volunteers to give a personal example. Move into one or two scenarios involving impulse control and have them discuss in groups or all together.
   1. Provide them with a case study of traumatic brain injury and using their computers, research some effects or famous cases of TBI. Have them relate this back to what they learned about the frontal lobe. You could provide articles to extend this activity, or present more information on what happens in the brain during concussive blows.