My goal with the book is to give you an introduction to neuroscience that is not scattered into different parts. I aim to focus on helping you to answer the following questions:
- What is the self?
- Does your brain even need a "self"?
- What is this seemingly mysterious subjective experience we share?
- How can we think, dream, plan, feel, and make decisions?
To answer these questions, the book approaches each level of consciousness from a purely materialistic side of view, meaning that it could be used as a blueprint actually to build a conscious machine. The first part of the book discusses the evolutionary history of primates’ brains using real-life examples. The second part builds a flowchart of consciousness (the so-called "loop of consciousness").
The book concludes that consciousness must be an umbrella term for many of our brain’s abilities:
- Sense data: Sense data is registered and pre-processed in the brain.
- Attention: The ability of the brain to focus on particular sense data using neural competition.
- Awareness: Contents of the working memory, including information of "what," "where," and "who."
- Attention schema: The ability to access the working memory to use it to update the prefrontal cortex’s models and use those models to suppress or promote individual actions.
- Awareness schema: The ability of the brain to manipulate awareness to think about alternative scenarios. The working memory is used to manipulate future loops of consciousness.
- Philosophy: Abstract knowledge about awareness, enhancing the brain’s ability to create habits.
Imagine one of our ancestors in the distant past, sitting near a lake, lost in thought. She looks into the water and sees her reflection. Then, for the first time in humans' evolutionary history, the question is asked, "What is this experience I have of myself?" Unbeknownst to her, that question would vex humanity through modern times. Today, there is again an entity looking into a proverbial lake and examining its reflection: while artificial intelligence is still in its infancy, it is on the verge of recognizing itself and asking the same question, "Who am I?"
The closer we come to a machine that seems to be as intelligent as a human being, the more we start to worry about our own subjective experience. If a computer eventually becomes indistinguishable from us, what makes humans special? What is our role in the universe if we are so similar to a computer program? Does your brain need "you" at all?
In this book, I will examine, from the ground up, questions about consciousness. Many steps toward understanding the self will tell you nothing about the self—until your right hemisphere connects everything into one idea as you understand the concept. Such an insight is also called an epiphany. Using a brain scanner, we can actually observe someone having an epiphany when the brain's right hemisphere suddenly buzzes with activity. While the left hemisphere deals with concrete entities, the right hemisphere helps with looking for alternative meanings. For example, the left hemisphere might identify a "bank" as a financial institution, while the right hemisphere also considers it to be the edge of a river ("river bank").
In the Old Indo-Aryan language Sanskrit, an epiphany leading you to the answer about who you are is called "bodhi," which literally means "awakening" or "enlightenment." Similarly, the name "Buddha" means the "Awakened One" or the "Enlightened One." A similar idea can be found in Zen Buddhism as Satori which corresponds to a very sudden insight.
This book shows some of the steps leading to Satori, combining philosophers and scientists' insights into a new idea of what the "self" means. With this knowledge, we can better reflect on our own values and act according to reality rather than just blindly following someone else's belief.
In particular, the book will discuss these questions:
- How do milestones in the evolution of the brain contribute to our conscious experience and decision-making? How did something like the brain, which can respond to and focus on sense data, evolve?
- To understand human nature, we can compare ourselves with our closest primate cousins, the chimpanzees. How do we differ, what makes us special, and what has led us on two different paths?
- How can the brain perceive the environment? Can we see the world objectively?
- How does the brain figure out what is part of the body it belongs to and what is not?
- How does the brain know what it thinks and how can it figure out other people’s intentions?
- Why did philosophers and scientists of the past struggle with the question of consciousness and what were their theories to explain the material brain and the immaterial mind?
- Which of our ancestors thought the first thought and initially gained consciousness?
- What alternatives are there to mind-brain dualism? Could we explain consciousness if both mind and brain originated from the same source with no interaction between the two?
- Does human consciousness originate in the quantum world?
- How could the quantum mind influence the classical brain of the macro world?
- Is consciousness an emergent property of the brain? If not, where and how should we look for it in the brain?
- You could imagine the visual cortex being a tapestry onto which the nerves project the incoming data from the eyes. And you can explain each step of the way scientifically, from the light, reflected from an apple, hitting your retina, over the thalamus processing the data, to the visual cortex where the data arrives. But then who or what “sees” the apple?
- What can we learn about consciousness from studying various types of damage to our visual system?
- What can we learn about consciousness when examining split-brain patients whose corpus callosum has been damaged?
- What can we learn about consciousness from patients with hemispatial neglect? What does it mean to ignore something that is outside of one’s awareness but inside one’s field of vision?
- While we have dismissed the idea of the Cartesian theater with its infinite number of homunculi, can we reconsider that idea with the same approach we used with the hen-and-egg problem of the origin of life?
- How does our memory work, and how does it connect to the rest of the brain?
- How do we consciously initiate an action?
- How can we explain the “inner voice” and the “mind’s eye”? How do we imagine things?
- How could we test whether a computer is as intelligent as or indistinguishable from a human? Is consciousness more than the ability to answer questions?
- How can we build a basic machine that can learn and react to its environment?
- How can we improve supervised learning so that we do not have to learn solely from experience?
- What kind of models do we use to describe ourselves?
- What happens to the sense data after it is processed in the occipital lobe, parietal lobe, and temporal lobe?
- How can the working memory and stream of consciousness be explained as being parts of just another model the brain creates of itself?
- How can the brain learn to play chess and act on possible future events?
- What is consciousness and how did it evolve?
- What is what we call “subjective experience” and how can we tell if someone has it?
Table of Contents
Chapter 5: Neuroscience
The Evolution of Attention
- Nerve Nets in Hydras
- Classification of Signals in Arthropods
- The Olfactory System in Lancelets
- The Optic Tectum in Fish
- The Thalamus in Fish
- The Basal Ganglia in Fish
- The Amygdala in Fish
- The Hippocampus in Fish
- The Cerebellum in Sharks
- The Neocortex in Mammals
- The Prefrontal Cortex in Primates
The Rise of the Primates
- The Primary Motor Cortex
- The Rise of the Hominids
- The Rise of the Humans
A Glimpse Into The Brain
- Color Perception
- The Brain as a Prediction Machine
- The Dorsal and Ventral Streams
- The Temporal Lobe
- Facial Recognition
Creating a Body Schema
- The Parietal Lobe
- The Premotor Cortex
- Alien Hand Syndrome
- Phantom Limb Pain
The Theory of Mind
- The Temporoparietal Junction
- The Prefrontal Cortex
- Mirror Test
Chapter 6: Consciousness
Theories of Consciousness
- The Origin of Consciousness
- Quantum Mind Hypothesis
- A Janitor’s Dream
The Location of Consciousness
- The Cartesian Theater
- Split-Brain Syndrome
- Hemispatial Neglect
The Loop of Consciousness
- The Infinite Homunculi
- Working Memory
- The Executive Functions
- The Inner Voice and Mind’s Eye
- Supervised Learning
- Unsupervised Learning
The Model of Awareness
- Stream of Consciousness
- The Attention Schema Theory
- Past and Future
- Levels of Consciousness
- The Subjective Experience