The human brain is one of the most fascinating and powerful structures on the planet. It receives input from our five senses, sends output to our organs and muscles, and with this information it constructs the subjective experience we know as life.
Let’s take a closer look at each region of the brain and its associated functions.
The frontal lobe is the seat of our executive functions and voluntary/learned behaviors. It sits just behind our foreheads and extends up the front of the head. The frontal lobes are integral to problem solving, reasoning and planning for the future. It also plays an important role in motivation and arousal, as well as attention and focus. Interestingly, the frontal lobes possess many inhibitory functions having to do with emotional reactivity and social behavior. In many ways, it is the culmination of these processes that give rise to our unique personality and emotional disposition.
An aspect of our short-term memory known as working memory is processed in the frontal lobe, granting us the ability to recall and manipulate recently acquired information in real time. Expressive language function resides in the left hemisphere of frontal lobe, giving rise to expressive speech. Unbeknownst to many, the primary motor cortex is also a part of the frontal lobe, responsible for the function of voluntary motor activity.
The parietal lobes have an array of different functions revolving around sensory recognition processing and visual-spatial orientation. It is more-or-less located beneath the crown of the head. Similar to the primary motor cortex, each hemisphere of the primary somatosensory cortex receives all somatosensory information (soma meaning body; sensory meaning sensation) from the contralateral (opposite) side of the body. This means that sensory input from the left side of the body is processed in the right parietal hemisphere. This allows us to differentiate between left and right, as well as to feel our body in space (an awareness called proprioception). The parietal lobe is also involved in some academic abilities such as reading, writing and calculation.
The temporal lobes contain a large amount of substructures and are located along the sides of the head just behind the temples and ears. These lobes are essential for auditory perception and the interpretation of both verbal and non-verbal (music) auditory stimuli. The recognition and therefore memory of language is specifically housed in the left temporal cortex, contributing to the non-motor aspects of language formation. Many other forms of long-term memory acquisition are housed within the temporal lobes such as visual memory (object and face recognition), and declarative memory (facts and events). The temporal lobes also play a primary role in emotional memory and reactivity; a result of it’s intimate connections with neighboring limbic structures, such as the amygdala. Our ability to recall emotional conditioning, such as comfort associated with grandma’s cookies or trauma associated with loud noises, is a result of the interplay between these two systems.
The occipital lobes located at the back of the head contain both the primary visual cortex as well as visual association areas. These lobes are responsible for the reception of visual stimuli via the eyes and the subsequent interpretation of that information. The stimuli received by the rods and cones within the eye are processed here as our perception of color. The occipital lobes also contribute to the perception and recognition of written words, allowing for the ability to read.
The cerebellum is a unique lobe located at the back underside of the brain, beneath the occipital lobe. It is actually not directly connected to any of the four lobes mentioned above, but rather to the brainstem. The cerebellum is primarily involved in fine motor control and motor learning. It receives sensory information from the peripheral body, the spinal cord, and many other parts of the brain in order to integrate and coordinate voluntary movement. The cerebellum helps the body learn movements that require practice and precision, such as riding a bike. It is also integral to posture, balance, accurate timing, and even certain cognitive functions such as language.
The brain stem is one of the oldest regions of the brain yet one of the most vital for our body’s survival. Structurally continuous with the spinal cord, the brain stem can be thought of as an information highway between the brain and the rest of the body. It consists of the midbrain, pons, and medulla oblongata. These structures collectively control vital bodily functions such as heart rate, blood pressure, breathing, swallowing, body temperature regulation, and digestion. The brain stem is also responsible for wakefulness/alertness, sleep, and consciousness. It is directly connected to our autonomic nervous system, as well as many important survival reflexes including our startle response.
The limbic system is a collection of structures deep within the brain that are involved in processing and regulating emotions, memory, and arousal. It’s primary structures include the amygdala, hippocampus, thalamus, and hypothalamus. These structures are responsible for our emotional reactivity, emotional memories, the formation of new memories, as well as our endocrine activity and stress response systems. The limbic regions can collectively be thought of as an integration system of higher cognitive function and primitive emotion.
While each brain region contributes to a certain set of functions, it is important to realize that the brain is a highly interconnected network of systems, rich in complexity and coordination.
When designing neurofeedback protocols clinicians take into account a combination of behavioral symptomatology and the electrical activity within each region of the brain. Depending on the patient’s age-normed QEEG results, specific locations on the scalp are utilized in order to normalize the electrical activity of underlying brain regions. Over multiple sessions, behavioral symptoms that correlate with that brain regions functions are able to subside.