The Limbic System

The Limbic System

The Limbic System is a complex group of interconnected structures deep within the brain that is primarily involved in emotion, motivation, memory, and certain survival behaviors (like feeding, reproduction, and fight-or-flight responses).2

It is often referred to as the emotional nervous system because of its profound influence on how we feel and react to the world.³

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🧠 Major Components and Functions

While the exact components can vary slightly depending on the source, the core structures of the limbic system and their primary functions are:

Structure	Shape/Location	Primary Role
Amygdala	Almond-shaped, near the hippocampus	Processes emotions, especially fear and anger. Essential for forming memories tied to strong emotions (emotional valence).
Hippocampus	Seahorse-shaped structure	Crucial for forming new long-term memories (memory consolidation) and spatial memory (navigation).
Hypothalamus	Sits below the thalamus	Regulates the Autonomic Nervous System (heart rate, blood pressure, body temperature) and the endocrine system (hormone release). Involved in hunger, thirst, sex drive, and the body's response to stress.
Cingulate Gyrus	Arch-shaped structure above the corpus callosum	Involved in emotion formation, pain processing, learning, and linking behavioral outcomes to motivation.

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📍 Location and Context

The limbic system structures are located on the border ("limbus" is Latin for border) between the older, subcortical areas (like the brainstem) and the newer, sophisticated cerebral cortex.⁴

It is considered an evolutionarily ancient part of the brain, involved in the basic instincts necessary for survival.⁵ It works in conjunction with other parts of the brain, particularly the prefrontal cortex, which provides the executive control necessary to regulate and modulate the emotional impulses generated by the limbic system.

OTHER SOURCES

The brain parts that you do not often see in drawings is found deep within the brain. This brain part is called the limbic system and is involved in emotions and basic drives. Some refer to the limbic system as the lower brain, not only because of where it is located, but because it handles the things about us that are a bit less civilized.

 For example, the amygdala and nucleus accumbens are important for processing fear and reward. They are also involved in drug, alcohol and other addictions. The cingulate gyrus runs the day to day activities of the body that we do not directly control, like heart rate and blood pressure.

One interesting part of the limbic system that actually resides in the parietal cortex is called the hippocampus. The hippocampus is the brain part that forms memories. You have one of these on each side of the brain. 

If one hippocampus is injured, say by a stroke, the other one will still allow your brain to make memories. However, if both hippocampi are removed, as was once done through surgery, then you cannot form new memories! 

This horrible thing happened to a person that underwent surgery to prevent almost continuous, life-ruining seizures. 

After the surgery, it was found that the person could only remember things that happened prior to the surgery and could not make new memories. 

Each day, in fact each new moment was a confusing, perpetual question of How did I get here?

 Needless to say this surgery never happens anymore but this terribly unfortunate occurrence demonstrates the importance of the hippocampus in memory.

Diagram of Brain...

Diagram-of-brain-frontal-lobe

DIAGRAM OF BRAIN : CEREBELLUM

DIAGRAM OF BRAIN : CEREBELLUM

Diagram of the Brain: Cerebellum

The human brain is divided into several major regions, each responsible for specific functions. One of these important regions is the Cerebellum, located at the lower back part of the brain, just beneath the Occipital Lobe and behind the Brainstem.

The Cerebellum is often referred to as the “little brain” because of its rounded, wrinkled structure that resembles a smaller version of the main brain. It plays a vital role in movement coordination, balance, posture, and motor learning.

In a typical brain diagram:

• The Frontal Lobe is at the front, controlling decision-making, movement, and personality.

• The Parietal Lobe is at the top-middle, handling touch, pressure, and spatial awareness.

• The Temporal Lobe is on the side, involved in hearing, memory, and speech.

• The Occipital Lobe is at the back, responsible for vision.

• The Cerebellum, highlighted near the lower rear of the brain, appears as a distinct section with horizontal grooves.

It is connected to the brainstem and ensures that all physical movements are smooth and precise. Damage to the cerebellum can lead to loss of balance, uncoordinated movement, or difficulty walking.

DIAGRAM OF BRAIN : CEREBELLUM Video

DIAGRAM OF BRAIN (Temporal Lobe)

DIAGRAM OF BRAIN: TEMPORAL LOBE

Temporal Lobe Overview

• Location: Lower middle part of the brain, beneath the lateral sulcus (Sylvian fissure), roughly behind the temples.

• Function:

  • Auditory processing – interprets sounds and language.

  • Memory formation – houses the hippocampus.

  • Emotion processing – connected with the limbic system.

  • Understanding language (Wernicke’s area in the left hemisphere).

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Simple Diagram of the Brain Showing the Temporal Lobe

Top View (simplified):

       Frontal Lobe
       ┌───────────┐
       │           │
       │ Frontal   │
       │           │
       └─────┬─────┘
             │
     Parietal │
       Lobe   │
 ┌───────────┴───────────┐
 │                       │
 │     Temporal Lobe     │  <- beneath lateral sulcus
 │   (auditory & memory)│
 └───────────┬───────────┘
             │
        Occipital Lobe

Side View of Brain (simplified):

      [Frontal Lobe]
           ____
          /    \
         |      |
         |      | 
         |______|
         |      |
         |      |  
         |Temporal| <- Temporal Lobe (side/lower brain)
         | Lobe  |
         \______/
         |      |
         |Occipital|
         |  Lobe   |
         \______/

Tip: The temporal lobe sits below the parietal and frontal lobes, near your ears, which is why it’s heavily involved in hearing.

Temporal Lobe - There are two temporal lobes, one on each side of the brain located at about the level of the ears. These lobes allow a person to tell one smell from another and one sound from another. They also help in sorting new information and are believed to be responsible for short-term memory.

Brain Right Lobe - Mainly involved in visual memory (i.e., memory for pictures and faces).

Brain Left Lobe - Mainly involved in verbal memory (i.e., memory for words and names).

Diagram of Brain

diagramofbrain-/thalamus.

DIAGRAM OF BRAIN (Parietal Lobe)

DIAGRAM OF BRAIN : PARIETAL LOBE

Parietal Lobe Overview

• Location: Upper middle part of the brain, behind the frontal lobe and above the occipital lobe.

• Function:

  • Processes sensory information (touch, pressure, temperature, pain).

  • Spatial awareness and navigation.

  • Hand-eye coordination and manipulation of objects.

  • Understanding language and mathematics (in some areas, like the left hemisphere).

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Simple Diagram of the Brain Showing the Parietal Lobe

         Frontal Lobe
       ┌───────────────┐
       │               │
       │   Frontal     │
       │               │
       └──────┬────────┘
              │
   Parietal   │
   Lobe       │
 ┌────────────┴───────────┐
 │                        │
 │   Sensory Processing   │
 │                        │
 └────────────┬───────────┘
              │
         Occipital Lobe

Or if visualized on a side-view of the brain:

Side View of Brain:

      [Frontal Lobe]
           ____
          /    \
         |      |
         |      |  <- Parietal Lobe (top-middle)
         |______|
         |      |
         |      |  <- Occipital Lobe (back)
         \______/ 

Tip: On an actual brain, the central sulcus separates the frontal lobe (motor functions) from the parietal lobe (sensory functions).

Parietal Lobe - One of the two parietal lobes of the brain located behind the frontal lobe at the top of the brain.

Parietal Lobe, Right - Damage to this area can cause visuo-spatial deficits (e.g., the patient may have difficulty finding their way around new, or even familiar, places).

Parietal Lobe, Left - Damage to this area may disrupt a patient's ability to understand spoken and/or written language.

The parietal lobes contain the primary sensory cortex which controls sensation (touch, pressure). Behind the primary sensory cortex is a large association area that controls fine sensation (judgment of texture, weight, size, shape)

Diagram of Brain Video
diagram-of-brain-cerebellum.

DIAGRAM OF BRAIN (Occipital Lobe)

The occipital lobe is the smallest of the four lobes of the brain, located at the back of the skull, and is primarily responsible for visual processing. It receives visual information from the eyes and processes it to allow us to see, recognize objects, and understand spatial relationships. 

Key Functions of the Occipital Lobe:

Visual Processing:

The occipital lobe is the main area for visual processing, including color, form, and motion. 

Visual Perception:

It allows us to perceive and interpret what we see, including recognizing objects, faces, and places. 

Spatial Awareness:

It helps us understand the location of objects in our environment and our own position in space. 

Coordination with other lobes:

The occipital lobe works with other brain areas, like the parietal and temporal lobes, to enhance visual experiences and integrate visual information with other senses. 

Memory and Learning:

It plays a role in visual memory and learning, including recognizing familiar objects and scenes. 

Potential Issues from Occipital Lobe Damage:

Visual Deficits: Damage can lead to various visual impairments, such as blurred vision, color blindness, and difficulty recognizing objects or faces. 

Spatial Disorientation: Difficulty locating objects or navigating the environment. 

Reading and Writing Problems: Inability to recognize or process written words. 

Visual Hallucinations: Experiencing visual sensations that are not actually present. 

Epilepsy: Seizures can originate in the occipital lobe. 

Location and Structure:

The occipital lobe sits at the back of the head, beneath the parietal and temporal lobes. 

It is separated from the parietal lobe by the parietooccipital sulcus. 

The occipital lobe contains the primary visual cortex (V1), which receives initial visual input, and secondary visual areas, which further process visual information. 

DIAGRAM OF BRAIN

The occipital lobe is the smallest of the four brain lobes, situated at the rear of the skull, and is chiefly responsible for visual processing. It receives visual data from the eyes and processes it, enabling us to see, identify objects, and comprehend spatial relationships.

Key Functions of the Occipital Lobe:

Visual Processing:

The occipital lobe serves as the primary region for visual processing, encompassing color, shape, and movement.

Visual Perception:

It enables us to perceive and interpret visual stimuli, including the recognition of objects, faces, and locations.

Spatial Awareness:

It assists in understanding the positioning of objects within our surroundings and our own location in space.

Coordination with Other Lobes:

The occipital lobe collaborates with other brain regions, such as the parietal and temporal lobes, to enhance visual experiences and integrate visual data with other sensory inputs.

Memory and Learning:

It contributes to visual memory and learning, including the recognition of familiar objects and scenes.

Potential Issues from Occipital Lobe Damage:

Visual Deficits: Damage may result in various visual impairments, including blurred vision, color blindness, and challenges in recognizing objects or faces.

Spatial Disorientation: Difficulty in locating objects or navigating through the environment.

Reading and Writing Problems: Inability to recognize or process written text.

Visual Hallucinations: Experiencing visual sensations that do not actually exist.

Epilepsy: Seizures may originate in the occipital lobe.

Location and Structure:

The occipital lobe is positioned at the back of the head, beneath the parietal and temporal lobes.

It is separated from the parietal lobe by the parietooccipital sulcus.

The occipital lobe houses the primary visual cortex (V1), which receives the initial visual input, along with secondary visual areas that further process visual information.