There is a huge amount about our brains that we still don’t know and really the human brain remains one of the most incredible mysteries on the face of the Earth. Nevertheless, we are increasingly learning more and more about this crucial aspect of our biology and are discovering how physiological changes correlated with changes in our behavior and experiences.
Gradually for example, brain imaging studies and electrical stimulation have helped us to learn the rough organization of the brain and to discover how specific regions appear to be tied closely to specific tasks. Clusters of neurons dealing with things like perception, emotion and movement are found at precise regions of our brain and thus we are now able to locate the source of various problems affecting our mental health. Likewise, we can predict the outcome that damage to particular areas might produce.
But it would be too easy if these brain regions were given nice names that gave us clues as to their functions. Instead we have long Latin names that don’t exactly role off the tongue… It all sounds very complicated.
Read on then and we’ll go over some of the more important areas of the brain and what their roles are in governing our behavior.
The cerebrum is the largest part of the brain and is responsible for the majority of our brain’s functions relating to thought, perception and experience. The neocortex describes the parts of the cerebrum responsible for higher order thought. The cerebrum can be divided into four smaller areas, each with their own range of important tasks. These are as follows:
The Frontal Lobe
The frontal lobe, as the name suggests, is located at the front of the brain (behind your forehead) and is responsible for creative thinking, problem solving, judgment and attention. It is also in charge of coordinating movement, smelling and informing our personality.
Broca’s Area: Broca’s area is an area within the frontal lobe that is involved in speech and language and is also involved in the control of facial neurons. Deficits in speech known as ‘Broca’s aphasia’ are the result of damage to this area.
The Parietal Lobe
The parietal lobe is found in the cerebral hemisphere and controls tasks relating to perception and comprehension such as reading, language and tactile sensations. The parietal lobe itself also contains other important brain areas, which are:
The Sensory Cortex: Located in the front of the parietal lobe, the sensory is the first to receive information from the spinal cord about your body’s position in space.
The Motor Cortex: The motor cortex is the part of the brain that is responsible for controlling our movements and motor control as well as receiving sensations. The motor cortex itself can be seen almost as a ‘map’ with regions corresponding to each part of the body. What’s interesting though, is that the sizes of the areas in the motor cortex are dictated by the relative number of nerves and the resulting sensitivity rather than the size of that body part. For instance, the areas for the finger tips and lips are much larger than the areas for the torso and legs. The motor cortex is found at the top (dorsal region) of the brain in the middle.
The Temporal Lobe
The temporal lobe contains brain areas corresponding to visual and auditory memories. This also informs a range of other processes in the brain, including speech, hearing and behavior.
Wernicke’s Area: This is an area of the temporal lobe found around the auditory cortex. While it is not fully understood, it is known to play an important role in our speech and language comprehension with damage to this area resulting in speech impairments.
The Occipital Lobe
Located at the rear (posterior) of the brain, the occipital lobe’s job is to control and interpret visual stimuli. Here individual nerves correspond to nerves within the eye and stimulating them can make us ‘see’ points of light.
The cerebellum is sometimes called the ‘little brain’ and is found at the lower rear part of the brain underneath the cerebrum. It is considered to be older than the cerebrum in terms of our evolution and is involved in motor control, attention and language to a degree.
While all mammals and reptiles have a cerebellum, reptiles do not have a neocortex as they evolved earlier. Thus all the behavior that you observe in a reptile can come from the cerebellum, but more complex examples of planning, problem solving and creative thinking require the more recently developed cerebrum and neocortex.
The Limbic System
The limbic system refers to the brain areas that control our emotions and that release mood regulating hormones and neurotransmitters via glands in the brain. Located on both sides of the thalamus beneath the cerebrum, it is responsible for many of our more basal instincts and emotional reactions. For instance, the fight or flight response is governed by the limbic system.
Again, the limbic system can actually be broken down into numerous smaller parts. These include:
The thalamus is found at the center of the brain and controls our attention span and our interpretation of pain. It also monitors ‘input’ and helps us to keep track and pay attention to the right sensations in the brain. It likely plays an important role in learning by helping us to direct out attention and to place importance on the right stimulus, thereby being more likely to retain that information. This explains the phenomenon of the ‘flashbulb memory’, wherein people are likely to remember emotionally charged events in much more vivid detail as compared with less emotional instances.
The hypothalamus controls our mood as well as a range of other bodily sensations such as hunger, temperature and thirst. It is also responsible for a range of hormonal processes and can thus help to influence the metabolism.
The hippocampus is also involved in learning and memory and especially for converting short term memories into long term memories that are stored more permanently. If you are asked to remember a phone number while someone gets a pen, then this is your ‘short term memory’ at work. When you remember your own number permanently and can reproduce it at will however, this is an example of using your long term memory.
The hippocampus is also involved in memories relating to directions and locations.
The amygdala once again is involved in both memory formation and emotions – particularly fear. It is a large part of our ‘telencephalon‘ which is found in the temporal lobe.
The brain stem is the most primal part of the brain and is the part that has been around the longest in terms of our evolutionary history. All most basic life support functions occur in the brain stem – including things like our heartbeat, blood pressure, breathing and reflexes. It also contains the medulla, midbrain and pons which may have a role in the experience of dreaming.
The brain stem is considered the most basic part of the brain and most living creatures on the macroscopic scale have some approximation of a brain stem.
To put it more simply, if all the other areas of your brain were shut down, then you would stay alive by breathing and keeping your heart beating, but you would be unable to think, to emote or to form new memories.
The three main areas of the brain stem are as follows:
The midbrain is also sometimes known as the mesencephalon and is itself made up of the tegmentum and tectum. Its job is to regulate movement, sight and hearing and to transfer messages from other areas of the brain to the brain stem and spine to allow movement.
The pons is also found in metencephalon and once again has a role in movement, particularly in controlling posture and movement. It interprets sensory analysis and motor control and allows us to walk, run and catch without having to consciously ‘think’ about where we are going to move our legs or our hands to perform those jobs. Several theories also suggest that ‘firing’ in the pons may be the cause of dreaming during sleep.
This is the vital part of the brain, also called the medulla oblongata, which controls vital bodily functions required to keep us alive. Without the medulla you would require life support in order to continue breathing and pumping blood around your body.
This breakdown should give you a basic understanding of the different brain areas and how each relates to particular functions. It’s important to recognize however that these areas can be broken down many more times into more precise areas. There are even precise areas in the brain that appear to be dedicated to remembering the names of vegetables – or at least very localized brain damage can cause you to forget only the names of vegetables which strongly suggests that such an area exists.
It’s also useful to remember that while certain brain areas have dedicated ‘jobs’, most processes are actually the result of many different brain regions working together.