Brain Lobes: Locations and Functions
The brain is a remarkably complex organ comprised of billions of interconnected neurons and glia. It is a bilateral, or two-sided, structure that can be separated into distinct lobes. Each lobe is associated with certain types of functions, but ultimately, all of the areas of the brain interact with one another to provide the foundation for our thoughts and behaviors. In this section, we discuss the overall organization of the brain and the functions associated with different brain areas.
- The forebrain, midbrain and hindbrain are three distinct parts of the brain.
- The cerebrum is further classified in distinct lobes that as groups areas of the brain by their location and function.
- Each brain lobe has key areas where specific functions are processed.
A Closer Look at the Cerebrum
The surface of the brain is called the cerebral cortex. One thing you’ll notice about it, is how uneven – or ‘bumpy’ – it actually is. There are distinct patterns of folds and bumps known as gyri. Between each gyrus are these grooves, which we call sulci. Take a look at the figure to the right, the gyri These gyri and sulci form important landmarks that allow us to separate the brain into functional centers.
The most prominent sulcus, known as the longitudinal fissure, is the deep groove that separates the brain into two halves or hemispheres: the left hemisphere and the right hemisphere. There is evidence of some specialization of function—referred to as lateralization—in each hemisphere, mainly regarding differences in language ability. Beyond that, however, the differences that have been found have been minor. What we do know is that the left hemisphere controls the right half of the body, and the right hemisphere controls the left half of the body.
The two hemispheres are connected by a thick band of neural fibers known as the corpus callosum, consisting of about 200 million axons. The corpus callosum allows the two hemispheres to communicate with each other and allows for information being processed on one side of the brain to be shared with the other side.
The cerebral cortex, which is the outer surface of the brain, is associated with higher level processes such as consciousness, thought, emotion, reasoning, language, and memory. There are two hemispheres of the cerebral cortex and each cerebral hemisphere can be subdivided into four lobes (frontal, parietal, temporal, and occipital). Each brain lobe is associated with unique set functions, but either directly or indirectly, all lobes either communicate to produce behavior.
The frontal lobe is the most rostral part of the brain and extends back to a fissure known as the central sulcus (where the orange and blue lobes meet). The frontal lobe is involved in what is described as higher cognitive functions and executive control. Reasoning, emotion, self-control, flexible thinking, planning problem solving, personality and emotion are all functions that fall under the frontal lobe’s higher cognitive function. These function are processed by a particular structure called the prefrontal cortex. A very unique accident that happened to a man named Phineas Gage, gave us our first understandings of the prefrontal cortex and the frontal lobe.
The frontal lobe also controls voluntary movement through the primary motor cortex and production of speech through a region known as Broca’s area. interesting feature of the frontal lobe is it’s involvement in the production of speech. It’s important to distinguish the difference between the production of speech and the interpretation of speech; Broca’s area only invovled in the former.
The brain’s parietal lobe is located immediately caudal to the frontal lobe, and is involved in processing information from the body’s senses. It contains the primary somatosensory cortex, which is essential for processing sensory information from the entire body. Anything from touch, temperature, and pain is processed here. An interesting feature of the primary somtaosensory cortex is that it is topographical. This means that spatial relationships that exist in the body are mapped on the surface of the somatosensory cortex. For example, the portion of the cortex that processes sensory information from the hand is adjacent to the portion that processes information from the wrist.
The temporal lobe is located on the sides of the head (temporal means “near the temples”), and is associated with hearing, memory, emotion, and some aspects of language. Deep within the temporal lobe are structures like the hippocampus (which processes memory) and the amygdala (which processes emotion/fear). The auditory cortex, the main area responsible for processing auditory information, is also located within the temporal lobe. A specialized area called Wernicke’s area is important for speech comprehension and also located here.
The occipital lobe is located at the very back of the brain. It contains the primary visual cortex, which is responsible for interpreting incoming visual information. The visual cortex can process a range of visual information including color, motion, texture, shape and facial recognition. The organization of the visual cortex is called retinotopical. This means there’s a close relationship between the position of an object in a person’s visual field and the position of that object’s representation on the cortex. You will learn much more about how visual information is processed in the occipital lobe when you study sensation and perception.
Brain Lobes Review Notes
Location: Anterior; rostral
General Functions: Executive functions; planning; emotion; reasoning; problem solving; speech production; voluntary movement.
Notable Structures: Prefrontal cortex/pre-central gyrus; primary motor cortex; Broca’s area.
Location: Dorsal/superior; medial.
General Functions: Somatosensation
Notable Structures: Primary somatosensory cortex/post-central gyrus.
General Functions: Memory; emotion/fear; audition; speech comprehension.
Notable Structures: Hippocampus; amygdala; audition; Wernicke’s area
Location: Caudal; posterior.
General Functions: Visual processing: color; motion; texture; shape; face recognition.
Notable Structures: Primary visual cortex.
Brain Lobes Review Questions
- Consider the function of each brain lobe: how might the lobes need to communicate to coordinate the following behavior?
- Brushing your teeth.
- Scraping your shin.
- Planning for school.
- The pre-frontal cortex does not fully develop well into an individual’s 20s, how might this explain differences in behavior between adults and teenagers?
- What parts of the human brain do you think might be similar/different from other animals? Why?
- Frontal Lobe
- Prefrontal Cortex
- Primary Motor Cortex
- Broca’s Area
- Occipital Lobe
- Visual Cortex
- Temporal Lobe
- Auditory Cortex
- Wernicke’s Area
- Parietal Lobe
- Primary Somatosensory Cortex
- Spielman RM, Dumper K, Jenkins W, Lacombe A, Lovett M, Perlmutter. “”3.4 The Brain and Spinal Cord.” Psychology. OpenStax CNX. 2014. Houston, TX. https://openstax.org/books/psychology/pages/3-4-the-brain-and-spinal-cord. License: CC BY 4.0 License Terms: Edited & Adapted | Access for free at https://openstax.org/books/psychology/pages/1-introduction.
- OpenStax, Biology. OpenStax CNX. May 27, 2016 http://firstname.lastname@example.org. License: CC BY 4.0 License Terms: Edited & Adapted | Access for free at https://openstax.org/books/psychology/pages/1-introduction.