What is the most primitive part of the brain

Why did we pick these three areas of the brain? After all, there are quite a few other important brain features, like the cerebrum which controls speech, the cerebellum which controls movement, etc. Here’s why: these three parts of the brain teach three very important lessons:

1. The amygdala teaches us that sometimes our brain is flooded with emotion. Good news! It’s not our fault when we feel overwhelmed – it’s our amygdala taking over. Even better news! We can control that. We can teach kids strategies to overcome these amygdala hijacks.

2. The prefrontal cortex teaches us that we need to help our brain help us make good decisions, think clearly, and control our impulses. It is so powerful for kids to understand that their brain controls all of their actions, and that there are things they can do to stretch and grow their brain, and to regulate their emotions. 

3. The hippocampus teaches us that we need to strengthen and stretch our brains all the time so that we can remember everything we learn at school. Remembering is important! If you can’t retain what you learned in second grade, third grade is going to be pretty tricky. Kids need the reminder that they have to use their brain in order to learn.

You won’t believe how easy it is for kids to really learn and understand these three main parts of the brain. You haven’t lived until you’ve asked a three-year-old, “What part of the brain do we use to focus?” and she shouts back, “Pre-frontal cortex!

Additional reading/resources:

The brain is an immensely complicated and intricate organ, and by far the most complex organ to understand in the human body. Unfortunately for anyone who is taking AP® Psychology, it’s also something that you’re expected to understand for the AP® Psychology Exam. Luckily, you stumbled across this ultimate guide to the brain for AP® Psychology that we have prepared for you. In this AP® Psychology crash course review, we will provide a summary of the anatomy and function of the major areas of the brain.

The brain is divided into three main parts: the forebrain, the midbrain, and the hindbrain.

The Forebrain

The forebrain consists of the thalamus, hypothalamus, amygdala, and the hippocampus. The hypothalamus, amygdala, and hippocampus make up what we call the Limbic System of your brain.

Thalamus

The thalamus is located between the cerebral cortex and the midbrain. It is made up of nuclei that receive different sensory and motor inputs. The thalamus then relays these signals to various areas of the cerebral cortex. The thalamus also regulates consciousness, sleep and wakefulness, feeding and satisfaction and alertness.

Limbic System

The Limbic System is a group of brain structures that regulate basic emotions such as fear and rage and drives such as hunger and sex. The brain structures that make up the limbic system are somewhat controversial; however, the general consensus of the limbic system contains these three main structures: the hippocampus, the amygdala, and the hypothalamus.

Hippocampus: The hippocampus is vital for long-term memory formation, particularly declarative memories, or memories that can be purposely recalled like facts and events. Loss of function to the hippocampus results in the inability to form new memories.

Hypothalamus: Similar to the thalamus, the hypothalamus is made up of multiple nuclei with many different functions. The hypothalamus regulates the autonomic nervous system by producing and releasing hormones. Through its influence on the endocrine system, it can regulate sleep-wake cycles, respiration, and other autonomic responses.

Amygdala: The amygdala is the center of emotion and motivations. The amygdala is responsible for fear responses and learning out of fearful situations. The amygdala is also involved in regulation of memory consolidation or the process of turning a memory into long-term memory. The amygdala has also been linked to sexual and aggressive behavior and anxiety.

The Midbrain

The midbrain is made up of several smaller structures. It supports multiple functions including vision, hearing, motor control (especially eye movement), sleeping and waking, alertness and temperature regulation. For the AP® Psychology test, it is most important that you understand the functions I just listed and be familiar with the reticular formation. This structure controls our body’s general arousal and our ability to focus, and it is a collection of cells spread throughout the midbrain.

The Hindbrain

The hindbrain is the most primitive part of the brain. It regulates all of our most vital processes with three structures: the medulla, pons, and cerebellum.

The medulla controls automatic (involuntary) functions of the body, such as breathing, heart rate, and blood pressure.

The pons is part of the brainstem. It regulates several functions including hearing, equilibrium, taste and facial sensations and movements.

The cerebellum plays a role in motor control and movement including balance, subtle movement, and equilibrium. It also plays a role in cognitive functions such as attention and language.

The Cerebrum & The Cerebral Cortex

The cerebrum is the largest part of the brain. It is made up of two cerebral hemispheres (the left and the right hemispheres) that are separated by a large groove called the medial longitudinal fissure. The hemispheres are mirror images of each other, with some exceptions (Broca’s area, Wernicke’s area) which we will mention later. The hemispheres can share information with each other through a thick bundle of nerves running between them called the corpus callosum.

Each hemisphere is made up of the cerebral cortex, or the outer layer of tissue of the hemispheres, and smaller subcortical structures. These subcortical structures include the hippocampus, basal ganglia, and olfactory bulbs.

The basil ganglia is a group of nuclei that function as a unit. It plays a role in the goal-directed control of voluntary movements (like picking up a piece of fruit with your hand) and routine behaviors. The olfactory bulbs are structures involved in our sense of smell.

The cerebral cortex is what you picture when you think of what a brain looks like; it is the wrinkled surface of the brain that is a layer of neurons. As we grow and learn, the neurons in our cerebral cortex grow and connects with other neurons. The cerebral cortex is made up of four lobes: Parietal, Occipital, Temporal, and Frontal.

The Lobes of The Brain

The parietal lobe is located at the top of the brain, between the frontal and occipital lobe. It consists of the somatosensory cortex and is responsible for integrating sensory information from different parts of the body, especially visual information related to navigation and spatial orientation.

The somatosensory cortex is located right behind the primary motor cortex. This cortex is a system of nerves that respond to stimuli or changes to different areas of the body. Similar to the motor cortex, different areas of the cortex respond to stimuli of different parts of the body. The larger the body part on the image above, the more sensitive that part of the body is.

The occipital lobe is located in the back of the cerebral cortex. It is home to the primary visual cortex and the central area for visual processing, visual perception, and color recognition.

The temporal lobe is located beneath the lateral fissure on the cerebral hemisphere. Its primary function is processing auditory sensory input and is the location of the primary auditory cortex and Wernicke’s area. However, it also plays a role in interpreting meaning from visual stimuli and object recognition.

The primary auditory cortex is located only in the left temporal lobe, and it is important for understanding semantics in speech and vision.

Wernicke’s area is located in the back of the temporal lobe near the occipital lobe of the left cerebral hemisphere and is involved in understanding written and spoken language. Damage to this area results in the person being able to speak using proper grammar, syntax, and intonation, but the words they use will not make any sense.

Broca’s Area and Wernicke’s Area

The frontal lobe is located at the front portion of the brain and is home to many important brain structures including the primary motor cortex, prefrontal cortex, and Broca’s area.

The primary motor cortex regulates voluntary movements such as walking. Different areas of the cortex control different areas of the body.

The prefrontal cortex is located at the very front of the frontal lobe, and it controls executive functions or a set of abilities that are needed to control cognitive behaviors. These behaviors include attention, inhibition, working memory, problem-solving and planning.

Broca’s area is located in the left hemisphere in the frontal lobe. This area is responsible for speech production and language comprehension. Damage to this area can result in Broca’s aphasia. This is a condition in which you know what you want to say, but when you say it, it does not make sense.

The Four Lobes and Structures

How Do the Parts of Our Brain Connect?

An important thing to understand about the brain is how different sections communicate to each other. Information is conveyed from one brain region to another through brain cells called neurons. Neurons are made up of three main parts: the dendrites, the cell body, and the axon.

Neuron

Dendrites: The dendrites are short branched projections of the cell that receive electrochemical stimulation from neurons. This electrochemical stimulation causes a change in the electrical potential across the membrane of the cell. If the change in membrane potential reaches a particular threshold, it will cause a rapid and drastic change in potential called an action potential. The action potential causes a spread of the electrical activity through the cell body and down the cell’s axon.

Axon: The neuron axon is a long projection at the end of the cell opposite the dendrites. In some cases, the axon is insulated with myelin sheaths. These enable action potentials to travel down the axon faster because it only occurs in the spaces between the myelin sheaths rather than the whole axon. At the end of the axon are the axon terminals. These are branches at the end of the axon that spread signals to other cells. When the action potential reaches the axon terminals, it stimulates a release of chemical messengers called neurotransmitters onto another cell. The junction between the axon terminal and the dendrite of the receiving cell is called a synapse.

Typically, the neurotransmitter will excite the receiving cell causing the formation of an action potential and thus spreads the signal on to the next cell. However, some neurotransmitters can be inhibitory by preventing the formation of an action potential and thus ending the propagation of the signal.

Neurotransmitters

Some of the major neurotransmitters in the brain that you should be aware of for the AP® Psychology exam are listed below:

Acetylcholine: This neurotransmitter is typically released by motor neurons or neurons that activate muscles. It is also released inside the brain as a neuromodulator. That is a chemical that alters the way brain structures process information. It plays a significant role in arousal, attention, and motivation. It is also used by the autonomic nervous system for both sympathetic (fight or flight response) and parasympathetic (rest and digest) responses.

Dopamine: Dopamine is produced by dopaminergic neurons in the midbrain and the hypothalamus. Dopamine is typically used by the brain’s reward and pleasure centers. Its release motivates you to seek out pleasurable activity, whether it’s food, sex or drugs. It is also involved in regulating movement.

Norepinephrine: This neurotransmitter is the main neurotransmitter used by the sympathetic nervous system. It is used to activate whatever organ it is released on, to put it into a “fight or flight”, active state.

Serotonin: In the brain, serotonin is mainly released in the brainstem. Serotonin functions to decrease appetite, linked to reduce aggression and mood stabilization.

GABA: Also known as gamma-Aminobutyric acid (γ-Aminobutyric acid, GABA acts as an inhibitory transmitter, and thus prevents stimulation of the cell the GABAergic neuron projects onto.

Endorphins: Endorphins ae endogenous opioids. They function by inhibiting release of GABA resulting in an increase in dopamine in the brain. Because dopamine is associated with pleasure, the feeling of pleasure typically follows the release of endorphins. The receptors for these neurotransmitters are heavily concentrated in the pain neurocircuitry.

Other Cells in The Brain

Although neurons play a crucial role in the brain, this would not be possible without the other brain cells called glia or glial cells. Glial cells are the cells that support the neurons in many different ways. There are three glial cell types: astrocytes, oligodendrocytes, and microglia.

Astrocytes are star-shaped cells that perform several supportive functions to neurons and other cells in the brain. For example, astrocytes support endothelial cells that make up the blood-brain barrier, contribute to the repair and scarring process following an injury to the CNS, and act as guides for migrating neurons during brain development. Oligodendrocytes wrap myelin sheath around the axons of neurons in the brain. Microglia is the macrophages of the CNS. They are the primary form of immune defense in the brain and maintain the brain environment.

The Brain and The AP® Psychology Exam

The brain is the basis for the entire course, so you should anticipate seeing multiple choice questions on various aspects and structures of the brain.

Here is a sample question from AP® Central that would be similar to what you could see on the AP® Psychology exam:

Damage to the cerebellum would most likely result in which of the following problems?

a) Aphasia

b) Increased aggression

c) A loss of vision

d) A loss of motor coordination

e) A change in personality”

The cerebellum (located in the hindbrain), plays a role in your motor control and movement, which would make the answer D. Multiple choice questions on the brain in the exam will most likely be similar to this one; the exam tests how well you can understand and relate the structures of the brain to their functions.

It is also likely that some aspect of the brain and its structures could come up in the free response questions as well. There is enough information to know about the brain that it could be an entire FRQ by itself, but in the last seven years students have been asked to use or relate a structure of the brain in five different FRQs. In 2009, students were asked to relate several factors, including the cerebellum and the reticular formation, to someone taking a driver’s education course. In 2010, the exam had a question where students had to explain the behavior and perceptions of participants in a pep rally using a list of concepts, one of which was the occipital lobe. In 2011, one of the FRQs asked how Broca’s area related to the success and performance of someone who was learning a foreign language. In 2012, the first FRQ asked students to describe how the prefrontal cortex (among other concepts) related to a student making a decision about college. And again in 2015, the AP® Psychology exam had an FRQ that wanted to know how the prefrontal cortex could relate to a couple buying a new home.

Overview

What makes the different areas of the brain so complex to keep track of is that they are all connected in some way; this is great for our ability to think and learn, but not so great when you’re trying to remember if one structure is in the frontal lobe, the forebrain, or both. However, it will be best for your success on the exam to generally understand the different sections of the brain and more specifically understand the functions of the different structures reviewed in this Ultimate Guide to the Brain.

First, remember that the brain is split into three different section: the forebrain, the midbrain, and the hindbrain.

The structures in the forebrain include the thalamus, hypothalamus, amygdala, and hippocampus. The latter three are all part of the limbic system, which generally regulates basic emotion such as fear and rage. The midbrain generally supports multiple functions such as vision, hearing, and motor control; the only important structure in the midbrain that you need to know is the reticular formation. The important structures in the hindbrain that you will need to know are the medulla, pons, and the cerebellum.

Next, remember that the brain’s cerebrum and cerebral cortex are divided into two hemispheres (left and right) with four different lobes: frontal, parietal, occipital, and temporal. The frontal lobe houses the primary motor cortex, Broca’s area, and most importantly, the prefrontal cortex (which controls executive functioning). The parietal lobe’s primary structure includes the somatosensory cortex. The occipital lobe is important for its control of our visual processing. The temporal lobe’s important structures are the primary auditory cortex and Wernicke’s area.

Third, it’s important to understand how the areas of our brain connect. The information from the various structures is conveyed through our neurons, which are made up of dendrites, the cell body, and the axon. After all this information, if you can, you should try to understand the primary function of the various neurotransmitters listed above as well as the different cell types in the brain.

I know this may seem a lot of information. Take a deep breath; it’s going to be okay. The reason why there is so much to know is that understanding the brain is vital to understand psychology as a subject, not just for the AP® Psychology exam. The sections about the biological aspect of psychology (including the brain) is 8-10% of the exam as a whole, which is one of the few highest percentages that will show up. If you’re still unsure by the end of this, go through it again and see if re-reading will help. If there is any subtopic about the brain that you want us to go into more detail about, tell us! Do you have another topic that you want an Ultimate Guide to? Then let us know. And good luck!

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