Unit 2: Neuroscience
What makes you "you"? This question gets to the heart of one of the longest-running debates in psychology: the nurture versus nature dispute, which asks whether humans are a product of their environment or of their biological makeup. While it is unlikely that we will ever conclusively answer this question, research has provided us with some important insights that will assist you in understanding arguments on both sides of the debate. This unit will then explore our neurological system especially the structure and functions of neurons as well as parts of the brain. Early psychologists considered the brain a "black box" that controlled certain processes, though they did not know how to identify these processes or how the brain controlled them. This is no longer the case; nowadays, scientists insist that the psychological mind and physiological body are fully integrated with one another. Today, knowledge of the biological origins of our psychological states is integral to the study of psychology. The unit then explores the role and function of sleep as well as the use of substances in examining various states of consciousness.
Completing this unit should take you approximately 10 hours.
Upon successful completing of this unit, you will be able to:
- understand the role of genetics in human psychology, and how the nature-versus-nurture (gene-environment interaction) debate has informed the field of biopsychology;
- explain the structure and function of neurons, neural networks, neural communication, the brain, the spinal cord, the central nervous system, and the peripheral nervous system;
- describe the physiological effects of neurotransmitters and psychoactive drugs, and how they affect behavior;
- describe how researchers study and examine the brain and its functions, the behavioral effects of brain injuries, and the significance of split-brain operations;
- describe the endocrine system and the role of hormones in regulating body functions;
- describe the stages of sleep (REM and NREM), their importance in proper psychological function, and common sleep problems and disorders; and
- understand how substance use disorders are classified and differentiate among major drug categories (stimulants, depressants, antipsychotics, opioids, hallucinogens).
2.1: Biopsychology: Human Genetics
Read this section, which introduces the role of genetics in the study of psychology.
Read this chapter, which poses questions such as why is the concept of nature and nurture still studied today. Nature and nurture work together like complex pieces of a human puzzle. The interaction of our environment and genes makes us the individuals we are. As you review this unit think about yourself and how nature and nurture have aligned to make you the person you are today.
Watch this video about twin studies. Although researchers are working to expand and develop twin study designs and statistical methods, the assumptions made in many twin studies are being questioned. However, many researchers agree that twin studies will continue to be an important tool, alongside emerging genome and molecular research methods, in shedding light on human behavioral genetics.
Read this section about the risk factors for developing schizophrenia. It is clear that there are important genetic contributions to the likelihood that someone will develop schizophrenia, with consistent evidence from family, twin, and adoption studies.
2.2: The Nervous System
2.2.1: What Is a Neuron and Why Is It Important?
Read this section, which introduces biopsychology. After you read section 3.2, also read section 3.3, "Parts of the Nervous System". Biopsychology is a branch of psychology that analyzes how the brain and neurotransmitters influence our behaviors, thoughts and feelings. This field can be thought of as a combination of basic psychology and neuroscience.
Read this selection about neurons. Before moving on to the next assigned reading, you should be comfortable with the following key terms:
- action potential
- axon
- cell membrane
- dendrite
- electrostatic pressure
In addition, review the critical thinking questions at the close of the chapter to support your understanding of the materials.
- action potential
Watch this video on the anatomy of a neuron. You will see what a neuron looks like and how the neuron transmits signals. Think about how many signals are transmitted at any given time. Human beings are made up of very complex programming!
2.2.2: Action Potentials and Neurotransmitter Release & Functions
Watch this video about the action potential mechanism, which is essential for neural communication.
Watch this video, which explains the types of neurotransmitters and how they excite or inhibit neurons (nerve cells). Each neurotransmitter can directly or indirectly influence neurons in a specific portion of the brain, thereby affecting behavior. There are billions of nerve cells located in the brain, which do not directly touch each other. Nerve cells communicate messages by secreting neurotransmitters. Some common neurotransmitters are acetylcholine, norepinephrine, dopamine, serotonin and gamma aminobutyric acid (GABA). Acetylcholine and norepinephrine are excitatory neurotransmitters while dopamine, serotonin, and GABA are inhibitory.
2.3: The Brain and the Endocrine System
Read sections 3.4 and 3.5, "The Endocrine System", which will introduce you to the various parts and functions of the brain. Pay attention to how communication in the endocrine system differs from neurological processing.
The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Watch this video to understand how together, these organs are responsible for the control of the body and communication among its parts.
This video illustrates the nervous system especially the brain and peripheral nervous system.
Watch this video of the endocrine system and familiarize yourself with the major glands and hormones.
Watch this lecture on the brain and its importance to the study of psychology.
2.4: Brain Injuries
Watch this video to understand the cause and effect of strokes. Pay special attention to the discussion regarding how a stroke harms a person. Because brain cells need blood to supply oxygen and nutrients and to remove waste products, when brain cells are deprived of oxygen – as happens during a stroke – they cannot function properly. In addition, as you review the physical impacts of a stroke, think about how survivors of stroke experience many changes resulting from their illness. Most people are aware of the physical changes that occur following stroke, for example paralysis or weakness on one side of the body, or difficulty with speech and language comprehension. However many people also experience some changes in their mood. For some these changes last for a short time, yet others may have ongoing problems.
Read this article, and focus especially on the split-brain operation video. Afterwards, test your knowledge by describing a split-brain patient and at least two important aspects of brain function that these patients reveal.
2.5: States of Consciousness
2.5.1: Sleep
Read the introduction to Chapter 4 and sections 4.1 through 4.4. After you read, you should be able to differentiate between consciousness, biological rhythms, and sleep, and be able to characterize the different stages of sleep.
Read this article about how sleep is important in the functioning of our brain and how stages of sleep describe different levels of consciousness. This article also provides detailed information about the role of circadian rhythms in everyday functioning and explains different sleep disorders.
Watch this video on the importance and function of sleep.
Watch this video about sleep disorders.
2.5.2: Substance Use and Other States of Consciousness
Read sections 4.5 and 4.6, which cover how substances affect neurotransmitter functioning and alter states of consciousness.
Review this page, which describes the acute effects and the health risks of both legal and illegal drugs.
Read this page about drugs, their effects on the brain, and how psychological and physiological addictions form.
If you are interested in learning more about the science of drugs, the brain, and behavior, feel free to read the other sections of the website that discuss addiction prevention, health, treatment, and recovery.
Unit 2 Assessment
- Receive a grade Receive a pass grade
Take this assessment to see how well you understood this unit.
- This assessment does not count towards your grade. It is just for practice!
- You will see the correct answers when you submit your answers. Use this to help you study for the final exam!
- You can take this assessment as many times as you want, whenever you want.