Aspect that reinforces the brain-behavior relationship is the behavioral changes observed after brain injury. In fact, neuroscience is responsible for seeking links between specific brain structures and certain behavior. Mainly through the observation of brain-injured individuals.
Brain and Behavior Relationship.
Brain is a thinking organ that learns and grows by interacting with the world through perception and behavior (action). Mental stimulation improves brain function and actually protects against cognitive decline.
The original need for a nervous system was to coordinate movement, so an organism could go find food, instead of waiting for the food to come to it. Jellyfish and sea anemone, the first animals to create nerve cells, had a tremendous advantage over the sponges that waited brainlessly for dinner to arrive.
After millions of generations of experimentation, nervous systems evolved some amazing ways of going out to eat. But behind all the myriad forms of life today, the primary directive remains. In fact, a diminished ability to move is a good measure of aging. Inflexibility heralds death, while a flexible body and fluid mind are the hallmarks of youth.
Elastic comes from the Greek word for “drive” or “propulsion”. It is the tendency of a material to return to its original shape after being stretched. Elasticity is the basic animal drive that powers your muscles, giving you strength and balance – flexibility, mobility, and grace.
Plasticity is the basic mental drive that networks your brain, giving you cognition and memory, fluidity, versatility, and adaptability.
Before birth you created neurons, the brain cells that communicate with each other, at the rate of 15 million per hour! When you emerge into the world, your100 billion neurons primed to organize themselves in response to your new environment, no matter what your culture, climate, language, or lifestyle was.
The Brain, Master Organ of the Body- Brain and behavior.
The brain is the master organ of the body. From our eyes, ears, nose, and skin, the brain receives messages that tell us what is going on in the world about us. The brain also receives a steady stream of signals from other body organs that enables it to control the life processes.
The brain stores information from past experiences. This is why we can learn, remember, and think. The brain selects and combines messages from the senses with memories and emotions to form various thoughts and reactions.
Messages to the brain all pass through the brain stem. From the brain stem, they go to different parts of the brain for ‘processing.’ Messages go out through the grain stem to control the muscles and glands of the body.
The brain is vital to our existence. It controls our voluntary movements, and it regulates involuntary activities such as breathing and heartbeat. The brain serves as the seat of human consciousness: It stores our memories, enables us to feel emotions, and gives us our personalities. In short, the brain dictates the behaviors that allow us to survive and makes us who we are.
Divisions of the Brain.
The brain has three main divisions:
- The forebrain- controls what we think of as thought and reason.
- The midbrain- between the hind and forebrain, coordinates simple movements with sensory information.
- The hindbrain- structures in the top part of the spinal cord, controls basic biological functions that keep us alive.
Each division has many parts with special functions.
|Neocortex; Basal Ganglia; Amygdala; Hippocampus; Lateral Ventricles
Thalamus; Hypothalamus; Epithalamus; Third Ventricle
|Mesencephalon||Tectum; Tegmentum; Cerebral Aqueduct|
|Cerebellum; Pons; Fourth Ventricle
Medulla Oblongata; Fourth Ventricle
Found in the area of the forehead, this part of the brain is concerned with all the emotions, planning, organizing, reasoning, memory, movement, speech, recognition of auditory stimuli, visual processing, etc. It also deals with our imaginative abilities, creativity, judgments, opinions, etc. The forebrain can be again divided into three parts called the cerebrum, thalamus, and hypothalamus (part of the limbic system).
The cerebrum or the cortex is the large part of the brain and is associated with the cognitive functions of the brain, such as thinking and action. This cerebrum can again be divided into four sections or lobes called:
Lobes of the cortex:
The frontal lobe is located at the front of the brain and is associated with reasoning, motor skills, higher level cognition, and expressive language. At the back of the frontal lobe, near the central sulcus, lies the motor cortex. This area of the brain receives information from various lobes of the brain and utilizes this information to carry out body movements.
The parietal lobe is located in the middle section of the brain and is associated with processing tactile sensory information such as pressure, touch, and pain. A portion of the brain known as the somatosensory cortex is located in this lobe and is essential to the processing of the body’s senses.
The temporal lobe is located on the bottom section of the brain. This lobe is also the location of the primary auditory cortex, which is important for interpreting sounds and the language we hear. The hippocampus is also located in the temporal 10 Neurobiology and Behavior lobe, which is why this portion of the brain is also heavily associated with the formation of memories.
The occipital lobe is located at the back portion of the brain and is associated with interpreting visual stimuli and information. The primary visual cortex, which receives and interprets information from the retinas of the eyes, is located in the occipital lobe.
These four units together form the cerebrum.
Thalamus and Hypothalamus:
The thalamus is situated in the forebrain at the uppermost part of the diencephalon (posterior part of the forebrain). It’s an important part of the brain as all the sensory information we gather enters into this part, which is then sent via neurons into the cortex. All sensory inputs to the brain, except that of the sense of smell, are through the thalamus.
The hypothalamus lies ventral to the thalamus and is a part of the diencephalon. It deals with the function of homeostasis- thirst, hunger, emotions, control of autonomic nervous system and the pituitary gland. The hypothalamus is involved with the body’s vital drives and activities, such as eating, drinking, temperature regulation, sleep, emotional behavior, and sexual activity. It controls the functions of many internal body organs and helps coordinate activities of the brain stem.
Also known as the mesencephalon, this part is located behind the frontal lobes and in the center of the entire brain. It deals with functions such as hearing, vision, body and eye movements. The midbrain can be divided into three parts called the tectum, tegmentum and cerebral peduncles.
It is the smallest region of the brain that acts as a sort of relay station for auditory and visual information. The midbrain controls many important functions such as the visual and auditory systems as well as eye movement. Portions of the midbrain called the red nucleus and the substantia nigra are involved in the control of body movement.
The darkly pigmented substantia nigra contains a large number of dopamine-producing neurons. The degeneration of neurons in the substantia nigra is associated with Parkinson’s disease.
This is the posterior part of the brain, and is composed of cerebellum, pons and medulla. brain stem refers to the midbrain, pons and medullas. The hindbrain is located toward the rear and lower portion of a person’s brain. It is responsible for controlling a number of important body functions and process, including respiration and heart rate.
The brain stem is an important part of the hindbrain, controlling functions that are critical to life, such as breathing and swallowing. The cerebellum is also part of the hindbrain, playing a role in physical ability.\
The cerebellum forms the posterior part of the brain, just below the cerebrum. However, as compared to the cerebrum, its far smaller; 1/8 the size of the cerebellum. Small as it may seem, it performs crucial functions like balance, movement, coordinating muscle movements, etc.
It’s the cerebellum that helps us maintain our balance, move around. The very fact that we can enjoy all kinds of sport like surfing, skiing, etc. Without the cerebellum, we can say goodbye to even walking.
Pons and Medulla:
Pons and medulla along with the midbrain form the brain stem. This partnering act takes control of involuntary muscle movements in the body. For example, muscles of the heart and stomach work irrespective of our desire for them to function. Their movement is not in our control, but the brain stem controls it.
While running or performing vigorous exercises, it’s the brain stem that directs the heart to pump more blood. After a meal, it’s the brain stem that directs the stomach to digest the food. The pons and medulla also perform the crucial role of connecting the brain to the spinal cord, thus transform thoughts into actions.
- Engel, A., and Singer, W. 2001. Temporal binding and the neural correlates of sensory awareness. Trends Cogn. Sci.
- Gazaaniga, M. S. 1984. Handbook of Cognitive Neuroscience, Plenum Press: NY.