Processing the environment

This course is a part of MCAT, a 14-course Topic series from Khan Academy.

Foundational Concept 6: Biological, psychological, and socio-cultural factors influence the ways that individuals perceive, think about, and react to the world.

This course contains 13 segments:

Sensory perception

6A: Each day, we encounter various sights, sounds, smells, and tastes. Without an integrative centers, these many inputs would mean nothing to us. We will learn about how we perceive our various senses, including the theories, laws, and organizational principles that underly our ability to make sense of the world around us.

Sight (vision)

6A: Red, orange, yellow, green, blue. These words would have no meaning to you were it not for your properly functioning visual sensation. You are able to read this webpage because there are multitudinous synapses between the neurons in your eye, which detect light, and the neurons in the occipital lobe of your brain, which process this same image. We will break down how our eyes and brain are able to process the splendid world around us as photons bombard us from all around.

Sound (Audition)

6A: Listen carefully - that’s the sound of fingers on a keyboard. Why does it sound different from the sound of nails on a chalkboard? And why might your grandfather have difficulty hearing that faint noise whereas you have difficulty zoning it out? In this module, you will learn about how we hear, including the structure of the outer, middle, and inner ear, as well as the basics of auditory processing and cochlear implants.

Somatosensation

6A: When you hold a glass of water, your brain perceives senses many bits of information about the glass - its temperature, its size, and its location in space. We perceive the environment through our bodily senses, including our sensation of pain, temperature, pressure, balance, and movement. In this module you will discover how our body gathers this information and processes it so that we can make sense of the colorful world around us.

Taste (gustation) and smell (olfaction)

6A: Have you ever had difficulty tasting your favorite food when you had a stuffy nose? That’s because the senses of olfaction (smell) and gustation (taste) are intertwined. We will learn about the anatomy and physiology of these sensory systems as we explore their underlying molecular basis.

Sleep and consciousness

6B: One third of our lives is consumed by the mysterious process called “sleep.” There is a lot we don’t know about sleep, but we will discuss what we do understand in this module. You will find why napping for a twenty minutes in the afternoon may not be such a bad idea as you explore states of consciousness, circadian rhythms, sleep stages, and sleep disorders.

Drug dependence

6B: A drug is any chemical substance with a biological effect on an organism. Unfortunately, some people have addictions to drugs - 18.1% of all US adults smoke cigarettes, which have disastrous consequences on our health. You will come to appreciate the effects of drugs on our human physiology as we explore the mechanisms of psychoactive drugs such as depressants, opiates, stimulants, and hallucinogens.

Attention

6B: Have you ever tried to multi-task while frantically aiming to finish a large project? The phone goes off, you get a text message, all while you try to finish an essay or read a book. In an increasingly busy world, our attention is frequently distracted by so many inputs. Here you will explore the concept of selective and divided attention, as well as the role of language in cognition and development in our lives.

Memory

6B: Ever since you were in grade school, memory has been one of your best friends. I’m not talking about the RAM on your computer. Memory has helped you pass exams, remember the names of your friends, and made sure you know where you put your car keys. Hopefully you will remember how . We will examine the role of synapses in the physiology of neural networks such as these. You will also come to understand the structure of human memory; processes involved in normal encoding, retrieval, forgetting, and aging; and diseases affecting memory.

Cognition

6B: What is the difference between the thought processes of a five-year-old and a freshly-minted graduate with a Ph.D. in astrophysics? That would be cognition, the entirety of mental abilities relating to knowledge and memory. You will come to an understanding of cognitive development and intelligence, as well as how our minds solve problems, make decisions, and represent knowledge.

Language

6C: Were it not for the intricate structure of the English language, these letters on the webpage would be absolutely meaningless. As we grow up, we effortlessly pick up the syntax of our mother tongue, babbling as toddlers and maturing to write essays as teenagers. You will explore theories on the development of language and cognition and how our system of language may be disrupted by pathological neurological events like strokes.

Emotion

6C: You may tear up when you hear a friend’s story of heartbreak or burst out in laughter during the airing of your favorite sitcom. Were it not for the neural processing of emotion within your brain as you take in these sensory inputs, you would not feel sadness on hearing of the tragedy or glee while viewing the comedy. Here you will learn about the physiological, behavioral, and cognitive components of emotion as well as how the different areas of our areas of our brain play a role in emotion.

Stress

6C: Perhaps when you think about stress, you may think of that nerve-wracking sensation you may feel in your stomach before the final exam for organic chemistry you studied all month for or your shivering response to a chilly winter night. But stress can also be the microtraumas inflicted on yourself during exercise. Stress can be a good thing that forces our antifragile bodies to adapt to a changing external environment. Stress is the natural process by which we evaluate and respond to the challenges and threats of our environment. Jump into this playlist to learn about stressors, stress reactions, the effects of stress, and strategies to manage this wild process.