Introduction

You probably believe you have a mind. But what is a mind, and how do you know you have one? In this chapter, we’ll explore what counts as a mind, some ways to think about whether something has one or not, and give you some terms to help you describe what you believe about minds.

Can a worm make a decision?

Imagine you are a worm. You are hungry and you can smell food nearby, but you also smell danger! You’re not sure whether you should risk the danger to get to your food. How do you decide what to do?

Worms are capable of being “reasonable” in such situations. Consider a very tiny worm known as C. elegans. When presented with the smell of food nearby, but also a scary smell surrounding them, these worms behave as if they are following a sort of formula: the hungrier they are, the more likely they are to risk their life for some food¹.

“Some scientists consider this process to be decision-making. Is it?

Is it?

If your actions follow a formula like the one shown in Figure 1.1, are you really thinking? Or are you simply following an algorithm? The worm may have a set of neurons in its nervous system that performs a calculation. It might use sensory data to detect how hungry it is (h) and how much danger (d) it smells outside. Then, if h is greater than d, it leaves. If h is lower than d, it stays.

Consider the human version of this scenario in Figure 1.2. Sunny is a person with a complex human brain. He is hungry for his favorite restaurant’s noodles, but he is also lazy. He will only leave his couch if his hunger outweighs his laziness.

Sunny’s formula might be as simple as the worm’s (is hunger [h] greater than laziness [l]?), or, it could be more complicated – the way humans like to make things. Perhaps there is some hunger threshold G, and some laziness threshold M, and he’s following a series of rules like this:

It might be more complicated, but Sunny, like the worm, is still using an algorithm to decide whether or not he should leave his couch.

The term algorithm might sound modern, but it actually comes from someone very old: an Arabic philosopher from the 9th century A.D named Al-Khwarizmi, who wrote many, many texts on mathematics. Because an algorithm is a set of steps you follow (which is something that happens constantly in algebra), people have associated his name with the process in general. Through much time and many translations between languages, you might see how Al-Khwarizmi might turn into al – ka- riz – m, which then might turn into al-go-ri-thm.

We have wandered into 9th-century math in this book on cognition because human brains have not changed very much in 1,000 years. Ancient (and modern) mathematics follows logical steps, and so do our brains—even if it doesn’t always feel like it. Is Sunny’s decision in Figure 1.2 any different from the worm’s decision in Figure 1.1? This is the kind of question we’ll be tackling in this book and it’s ultimately up to you to decide.

Mind and Body

One thing to consider when answering questions like does a worm have a mind is whether the mind is separate from the body. Some people believe that all our thoughts, feelings, and experiences originate entirely from our brain, and we are nothing more than that. Others believe that while our brains control our body’s behavior, our essence is elsewhere. That is, we have souls, or non-physical selves. In philosophy, the first idea is a form of monism, where the mind is the same as the body. The second is a form of dualism, where the mind and body are separate.

Spirituality is a little outside the scope of this textbook, but it is important to many people. I want to be clear that the data we will discuss here is neither attempting to prove nor disprove the existence of the soul. Rather, we will focus on what the brain does, and you can fill in the rest!

It is difficult to discuss souls and minds without considering consciousness. Indeed, how we come to have conscious experience is a question that people have been trying to figure out ever since we had minds at all. A great example of how to answer this question comes from American philosopher Thomas Nagel in 1980. In What is it Like to Be a Bat?² Nagel proposes that an animal has consciousness if it is “like something” to be that animal. For example, imagine being a rock. Is it “like” something to be a rock? Does it feel like anything? If the answer for you is no, then you can probably say you don’t think a rock has consciousness. But what about a bat? If you were a bat, would it feel like something? Possibly! In that case, you would believe a bat has consciousness.

Nagel’s ideas bring into light something that is fundamentally unanswerable (at least within this book). Human experience—what it is like to be us—is something only you can experience for yourself, and something you can never experience for anyone or anything else. So, as we discuss cognition and memory in concrete terms, please remember all of this is only our best guess.

Can A Computer Be Conscious?

Speaking of whether it is “like” anything to be a bat, is it “like” anything to be a computer? What about being an artificial intelligence? Here’s what happened when I asked a chatbot:

The answer that the chatbot provided is likely unsurprising; it’s hard to imagine a bunch of code as something with a conscious experience. Over the years, many cognitive scientists have made comparisons between brains and computers. There are some valid comparisons. After all, humans made computers, and machine learning algorithms are often designed based on neurons. However, there are important differences as well. Some of these are technical (like how computers do math), but others are a little muddier. If a chatbot is built to have spontaneous conversations with itself, is that consciousness? If the same thing happens inside our squishy brains, is that not consciousness?