Unit 3 Biological Psychology
Overview
In Unit 3, we dive into biological psychology—the link between our brain and our behavior. As David Myers states (2015), the principle that everything psychological—every idea, every mood, every urge—is simultaneously biological is central to psychology today. Cells—particularly cells in the nervous system—play an incredibly important role in absolutely everything you do, from moving and sensing to thinking and feeling. Many different structural and functional imagining techniques have been used by a variety of psychologists to study individual’s with healthy, diseased, and traumatized brains to understand specific functions of this organ. This work brings greater understanding as to how cells function and communicate with each other as part of networks. As you become more familiar with the structure and function of the brain, you will better understand topics such as how we learn, how different drugs (both pharmaceutical and recreational) work, and how stress affects our bodies and brains. When studying the brain it can be helpful to start with the smaller parts (like neurons) and then look at the structure of the brain. Unit 3 is organized in this way, from communication between individual neurons to key structures in the brain. Krause et al. (2018) emphasise that the material that you will be reading will serve as a building block to deepen your understanding of almost all of the behaviours that make you “you.”
Learning Outcomes
When you have completed this unit, you should be able to:
- Describe the key terminology related to genes, inheritance, and evolutionary psychology, nerve cells, hormones, and their functioning, the nervous system, and with measuring and observing brain activity.
- Explain how twin and adoption studies reveal relationships between genes and behaviour, how nerve cells communicate, the ways that drugs and other substances affect the brain, and the roles that hormones play in our behaviour, how studies of split-brain patients reveal the workings of the brain.
- Apply your knowledge of genes and behaviour to hypothesize why a trait might be adaptive, of neurotransmitters to form hypotheses about drug actions, and how studies of animals with brain lesions can inform us about the workings of the brain.
- Apply your knowledge of brain regions to predict which abilities might be affected when a specific area is injured or diseased, and which neuroimaging techniques would be most useful in answering a specific research question.
- Analyze claims that scientists have located a specific gene that controls a single trait or behaviour, and explanations for cognitive gender differences that are rooted in genetics.
- Analyze the claim that we are born with all the nerve cells we will ever have, whether neuroplasticity will help people with brain damage, and whether neuroimaging can be used to diagnose brain injuries.
Activity Checklist
Here is a checklist of learning activities you will benefit from in completing this unit. You may find it useful for planning your work.
Learning Activities
- Read and Reflect – Chapter 3
- Review the Unit 3 – Course Notes (found on Course Notes tab)
- Complete the Neuroscience activity
- Complete the Head Transplants activity
Note
The course units follow topics in the textbook, Revel for An Introduction to Psychological Science by Krause et al. (4th Edition). For each unit, please read the pertinent chapter(s) before completing the assessment for the unit.
Assessment
In this course you demonstrate your understanding of the course learning outcomes in different ways, including papers, projects, discussions and quizzes. Please see the Assessment section in Moodle for assignment details and due dates.
3.1 Neural Communication
The human body is made up from a plethora of different types of cells. The cells of focus for Topic 1 are neurons, or nerve cells. Neurons are the building blocks of a body’s nervous system. Individually, a neuron cannot accomplish much, collectively, however, they produce the vast majority of your experience as a life form. To fathom our thoughts and actions, our memories and moods, we must first understand how neurons work and communicate.
There are billions of neural cells transmitting and receiving messages all day every day. Millions of them are firing as a result of the activities you are doing right now. To understand how this particular type of cell produces complex behaviours, it is necessary to take a closer look at the structure and function of the neuron.
Even though there are numerous types of neurons, the basic structure of them are the same (see A motor neuron below). Each neuron has a cell body with dendrites (branch like structures that receive messages from a sending neuron). Protruding from the cell body is a single lengthy axon fiber that, when stimulated, passes the message through to its terminal branches. From there the message is sent to other neurons or to muscles or glands. Some axons are encased in a myelin sheath, a layer of fatty tissue that insulates them, to increase the speed of transmission and speeds their impulses. The myelin sheath is very important for proper neural communication for smooth body movement. If the myelin sheath degenerates, communication to muscles slows and will with eventual loss of muscle control (this is the basis of multiple sclerosis).
Below is an image of a motor neuron:
The Neural Impulse
Neurons transmit messages when stimulated by signals from our senses or when triggered by chemical signals from neighboring neurons. In response, a neuron fires an impulse, called the action potential—a brief electrical charge that travels down its axon (Krause et al., 2018).
Each neuron makes “decisions” as it receives signals from hundreds, even thousands, of other neurons. Many of the signals are excitatory, moving a neuron towards an action potential. Some signals are inhibitory, they decrease the likelihood of an action potential. If excitatory signals exceed the inhibitory signals by a minimum intensity, or threshold, the combined signals trigger an action potential. The action potential then travels down the axon, which branches into junctions with hundreds or thousands of other neurons or with the body’s muscles and glands.
It is important to note that increasing the level of stimulation above the threshold will not increase the neural impulse’s intensity. The neuron’s reaction is an all-or-none response: like flushing a toilet, neurons either fire or they do not. To detect the intensity of different inputs, strong stimuli can cause more neurons to fire, and to fire more often. However, it does not affect the action potential’s strength or speed - just like pushing a toilet handle harder will not make a flush go faster.
To see a video on the activity of neurons and an action potential click:
Watch: Lights, Camera, Action Potentials!
Activity: Read and Reflect
Take a moment to read through chapter 3 of your textbook and review the Course Notes for this unit. Consider how some of the themes and concepts you read about apply to what you have learned in this section.
Activity: Neuroscience
For some, engaging in neuroscientific information can feel daunting. To help ease you into familiarity complex functions, the University of Washington has put together an excellent resource that offers simplified explanations of many different neuroscientific topics. The resource is called Neuroscience for Kids and the link is below. To look specifically at information we’ve discussed in this topic, click on the link, scroll down to The Neuron heading and then click on Making Connections: The Synapse!
After you explore this resource, consider the following questions:
- From what you have learned in this unit about neurons and neural communication, share your thoughts on why mental health professionals (counsellors, therapists, psychologists, and medical doctors) should care about human physiology?
Be prepared to share your thoughts and insights with other members of the class
3.2 The Brain
In Topic 2, we take our knowledge of nerve cells and look into how they work as an integrated system with a special focus on the brain. The brain is primarily composed of neural tissue and glial cells. The neural tissue comes in two forms – gray matter and white matter. Gray matter is composed of neural cell bodies; white matter is made up of myelin, the fatty sheath that covers axons. Glial cells are smaller than neurons, however, there are many more glial cells in your brain than neurons. Glial cells come in a number of shapes and they serve myriad functions in ensuring your brain works properly. It’s the activity of these cell that allows your brain to have seemingly limitless ability to store information. On top of that, your brain is responsible for your personality, preferences, memories, conscious awareness, and unconscious processes. This is very impressive considering your brain only weighs around three-pounds and is made up of approximately 100 billion individual neurons. The brain of animals, including humans, can be divided into three regions: the forebrain, the midbrain, and the hindbrain. Each of these regions is amassed by different brain structure with a variety of functions. The cerebral cortex, the outer most layer of the human brain is categorized into four lobes: the frontal lobes, parietal lobes, temporal lobes, and occipital lobes. It is important to note that though the brain is studied according to sections, the brain itself works as an integrated whole. Because of the integrated circuitry and feedback loops, destroying one area of the brain can have wide-ranging impacts throughout the organ.
It is humbling to think that nestled within your skull is perhaps that most complex entity in the entirety of the universe. As you learn about the brain, know that some of the greatest advances in understanding human thought and behavior have come through a greater understanding of the brain and the nervous system. Neuroscience is an area of psychology that continues to produce daily discoveries; you could study the brain for a lifetime and still only be scratching the surface of its capacity.
Activity: Head Transplants
As bizarre as it may sound, neurosurgeons now claim that transplanting a human head is possible. It has been done many times with dogs and monkeys, and the final barriers for employing humans seem to have been overcome. (The transplanted head would not be able to control the donor body.) If you underwent this process, who would you be, the person who donated the head, or the person who donated the body, or someone new? What if the body could be fully connected with all its neural connections to the head, would this change who you were?
Additionally, here are two links that are very fun for exploring information about the brain. The first link is to the Whole Brain Atlas. This will show you picture of the brain at a number of different depths and angles. The second is site contains general psychological tutorials and demonstrations. For information particular to this unit, click on the Biopsychology /Physiopsychology link on the home page
After exploring these resources, consider the following questions:
- What do you think of the “practical” applications of head transplant technology?
- What was something you found interesting from your explorations of the Whole Brain Atlas and/or Psychological Tutorials and Demonstrations? Try to be specific as to part(s) of the brain you would like to discuss or its functions.
Be prepared to share your thoughts and insights with other members of the class
Assessment
Refer to the course schedule for graded assignments you are responsible for submitting. All graded assignments, and their due dates, can be found on the “Assessment” tab.
In addition to any graded assignments you are responsible for submitting, be sure to complete all the Learning Activities that have been provided throughout the content - these are intended to support your understanding of the content.
Checking your Learning
Before you move on to the next unit, you may want to check to make sure that you are able to:
- Describe the key terminology related to genes, inheritance, and evolutionary psychology, nerve cells, hormones, and their functioning, the nervous system, and with measuring and observing brain activity.
- Explain how twin and adoption studies reveal relationships between genes and behaviour, how nerve cells communicate, the ways that drugs and other substances affect the brain, and the roles that hormones play in our behaviour, how studies of split-brain patients reveal the workings of the brain.
- Apply your knowledge of genes and behaviour to hypothesize why a trait might be adaptive, of neurotransmitters to form hypotheses about drug actions, and how studies of animals with brain lesions can inform us about the workings of the brain.
- Apply your knowledge of brain regions to predict which abilities might be affected when a specific area is injured or diseased, and which neuroimaging techniques would be most useful in answering a specific research question.
- Analyze claims that scientists have located a specific gene that controls a single trait or behaviour, and explanations for cognitive gender differences that are rooted in genetics.
- Analyze the claim that we are born with all the nerve cells we will ever have, whether neuroplasticity will help people with brain damage, and whether neuroimaging can be used to diagnose brain injuries.