Human and Machine Consciousness E-Book

David Gamez

• Herausgeber: Open Book Publishers
• Kategorie: Geisteswissenschaft
• Sprache: Englisch
• Veröffentlichungsjahr: 2018

Beschreibung

Consciousness is widely perceived as one of the most fundamental, interesting and difficult problems of our time. However, we still know next to nothing about the relationship between consciousness and the brain and we can only speculate about the consciousness of animals and machines.Human and Machine Consciousness presents a new foundation for the scientific study of consciousness. It sets out a bold interpretation of consciousness that neutralizes the philosophical problems and explains how we can make scientific predictions about the consciousness of animals, brain-damaged patients and machines.Gamez interprets the scientific study of consciousness as a search for mathematical theories that map between measurements of consciousness and measurements of the physical world. We can use artificial intelligence to discover these theories and they could make accurate predictions about the consciousness of humans, animals and artificial systems. Human and Machine Consciousness also provides original insights into unusual conscious experiences, such as hallucinations, religious experiences and out-of-body states, and demonstrates how ‘designer’ states of consciousness could be created in the future.Gamez explains difficult concepts in a clear way that closely engages with scientific research. His punchy, concise prose is packed with vivid examples, making it suitable for the educated general reader as well as philosophers and scientists. Problems are brought to life in colourful illustrations and a helpful summary is given at the end of each chapter. The endnotes provide detailed discussions of individual points and full references to the scientific and philosophical literature.

Leseprobe

HUMAN AND MACHINE CONSCIOUSNESS

Human and Machine Consciousness

David Gamez

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© 2018 David Gamez

This work is licensed under a Creative Commons Attribution 4.0 International license (CC BY 4.0). This license allows you to share, copy, distribute and transmit the work; to adapt the work and to make commercial use of the work providing attribution is made to the authors (but not in any way that suggests that they endorse you or your use of the work). Attribution should include the following information:

David Gamez. Human and Machine Consciousness. Cambridge, UK: Open Book Publishers, 2018. https://doi.org/10.11647/OBP.0107

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ISBN Paperback: 978-1-78374-298-1

ISBN Hardback: 978-1-78374-299-8

ISBN Digital (PDF): 978-1-78374-300-1

ISBN Digital ebook (epub): 978-1-78374-301-8

ISBN Digital ebook (mobi): 978-1-78374-302-5

DOI: 10.11647/OBP.0107

Cover image: Stereogram created by David Gamez with data from Anderson Winkler (https://brainder.org/research/brain-for-blender/) licensed under CC BY-SA 3.0.

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This book is dedicated to the first artificial system that understands it.

A flash, a mantling, and the ferment rises,

Thus, in this moment, hope materializes,

A mighty project may at first seem mad,

But now we laugh, the ways of chance forseeing:

A thinker then, in mind’s deep wonder clad,

May give at last a thinking brain its being.

[…]

Now chimes the glass, a note of sweetest strength,

It clouds, it clears, my utmost hope it proves,

For there my longing eyes behold at length

A dapper form, that lives and breathes and moves.

My mannikin! What can the world ask more?

The mystery is brought to light of day.

Now comes the whisper we are waiting for:

He forms his speech, has clear-cut words to say.

Goethe, Faust

Acknowledgements

I am extremely grateful to Barry Cooper and the John Templeton Foundation for supporting this work (Project ID 15619: ‘Mind, Mechanism and Mathematics: Turing Centenary Research Project’). This grant gave me the time that I needed to sit down and write this book.

I have really appreciated the help of Anil Seth, who supported my application for a Turing Fellowship and was very welcoming during my time at the University of Sussex. I am also grateful to the Sackler Centre for Consciousness Science and the Department of Informatics at the University of Sussex for giving me a place to work. I greatly enjoyed conversations about consciousness with my colleagues at Sussex.

I would also like to thank Owen Holland, whose CRONOS project started my work on human and machine consciousness, and the reviewers of this book, who had many helpful suggestions. I owe a warm debt of gratitude to my parents, Alejandro and Penny Gamez, who have always given me a great deal of support and encouragement.

Contents

List of Illustrations

1

1.

Introduction

3

2.

The Emergence of the Concept of Consciousness

9

3.

The Philosophy and Science of Consciousness

33

4.

The Measurement of Consciousness

43

5.

From Correlates to Theories of Consciousness

69

6.

Physical Theories of Consciousness

85

7.

Information Theories of Consciousness

93

8.

Computation Theories of Consciousness

103

9.

Predictions and Deductions about Consciousness

113

10.

Modification and Enhancement of Consciousness

125

11.

Machine Consciousness

135

12.

Conclusion

149

Appendix: Definitions, Assumptions, Lemmas and Constraints

159

Endnotes

165

Bibliography

201

Index

219

List of Illustrations

All images are © David Gamez, CC BY 4.0.

2.1.

Visual representation of a bubble of perception.

12

2.2.

The presence of an invisible god explains regularities in the visible world.

14

2.3.

Colour illusion.

17

2.4.

Primary and secondary qualities.

19

2.5.

The relationship between a bubble of experience and a brain.

21

2.6.

Interpretation of physical objects as black boxes.

23

2.7.

The relationship between a bubble of experience and an invisible physical brain.

25

2.8.

The emergence of the concept of consciousness.

28

3.1.

The use of imagination to solve a scientific problem.

35

3.2.

Imagination cannot be used to understand the relationship between consciousness and the invisible physical world.

38

3.3.

Learnt association between consciously experienced brain activity and the sensation of an ice cube.

39

4.1.

Problem of colour inversion.

51

4.2.

Some of the definitions and assumptions that are required for scientific experiments on consciousness.

53

4.3.

The relationship between macro- and micro-scale e-causal events.

58

4.4.

Assumptions about the relationship between CC sets, consciousness and first-person reports.

60

5.1.

The measurement of an elephant’s height in a scientist’s bubble of experience.

70

5.2.

Theory of consciousness (c-theory).

79

7.1.

Information c-theory.

97

8.1.

Soap bubble computer.

104

9.1.

Testing a c-theory’s prediction about a conscious state.

114

9.2.

Testing a c-theory’s prediction about a physical state.

115

9.3.

Deduction of the conscious state of a bat.

119

10.1.

Modifications of a bubble of experience.

128

10.2.

A reliable c-theory is used to realize a desired state of consciousness.

129

11.1.

A reliable c-theory is used to build a MC4 machine.

138

11.2.

A reliable c-theory is used to deduce the consciousness of an artificial system.

139

1. Introduction

© David Gamez, CC BY 4.0 https://doi.org/10.11647/OBP.0107.01

Consciousness is extremely important to us. Without consciousness, there is just nothingness, death, night. It is a crime to kill a person who is potentially conscious. Permanently unconscious people are left to die. Religious people face death with hope because they believe that their conscious souls will break free from their physical bodies.

We know next to nothing about consciousness and its relationship to the physical world. The science of consciousness is mired in philosophical problems. We can only guess about the consciousness of coma patients, infants and animals. We have no idea about the consciousness of artificial systems.

This book neutralizes the philosophical problems with consciousness and clears the way for scientific research. It explains how we can develop mathematical theories that can make believable predictions about consciousness.

The first obstacles that need to be overcome are the metaphysical theories of consciousness. Some people claim that consciousness is a separate substance; other people believe that it is identical to the physical world. These theories generate endless debates and it is very difficult to prove or refute them. This book eliminates some of these theories and suspends judgement about the rest.

The next obstacle is the hard problem of consciousness. This typically appears when people try and fail to imagine how colourful conscious sensations are related to the colourless world of modern physics. This book breaks the hard problem of consciousness down into a pseudo problem, a difficult problem and a set of brute regularities.

Some problems with consciousness cannot be solved. For example, we cannot prove that a person is conscious. These problems affect our ability to measure consciousness through first-person reports. This book neutralizes these problems by making assumptions. The results from the science of consciousness can then be considered to be true given these assumptions.

When these obstacles have been overcome the scientific study of consciousness becomes straightforward. We can measure consciousness, measure the physical world and look for mathematical relationships between these measurements. We can use artificial intelligence to discover mathematical theories of consciousness.

Eventually we will discover mathematical theories that map between states of consciousness and states of the physical world. We will use these theories to make believable predictions about the consciousness of infants, animals and robots. We will measure the consciousness of brain-damaged patients. We will build conscious machines, repair damaged consciousnesses and create designer states of consciousness.

The scientific study of consciousness is clarified by this book. As you read it the philosophical problems will dissolve and you will gain a clear vision of consciousness research. You will no longer worry about whether consciousness is a separate substance. You will not be troubled by a desire to reduce consciousness to particles or forces. You will understand that a scientific theory of consciousness is a mathematical relationship between a formal description of consciousness and a formal description of the physical world.

This book starts with a definition of consciousness. In daily life we treat colour, sound and smell as objective properties of the world. Over the last three hundred years science has developed a series of interpretations of the world that have stripped objects of their sensory properties. Apples used to be red and tasty; now physical apples are colourless collections of jigging atoms, probability distributions of wave-particles. The physical world has become invisible. When science eliminated sensory properties from the physical world it was necessary to find a way of grouping, describing and explaining the colours, sounds and smells that we continued to encounter in daily life. We solved this problem by inventing the modern concept of consciousness. ‘Consciousness’ is a name for the sensory properties that were removed from the physical world by modern science.

The next chapter examines some ‘hard’ problems with consciousness. First, it is impossible to imagine the relationship between consciousness and the invisible physical world. Second, we find it difficult to imagine the connection between conscious experiences of brain activity and other conscious experiences. Third, there are brute regularities between consciousness and the physical world that cannot be broken down or further explained. None of these problems are unique to consciousness research. They can also be found in physics and they do not affect our ability to study consciousness scientifically. We can measure consciousness, measure the physical world and look for mathematical relationships between these measurements.

Scientists measure consciousness through first-person reports, which raises problems about the reliability of these reports, the possibility of non-reportable consciousness and the causal closure of the physical world. The fourth chapter addresses these issues by making assumptions that explain how consciousness can be measured. First, we need to identify the systems that we believe are conscious. Then we need to make other assumptions to ensure that consciousness can be accurately measured in these systems.

The fifth chapter explains how we can develop mathematical theories of the relationship between consciousness and the physical world. Scientists have carried out pilot studies that have looked for correlations between consciousness and brain activity. We are now starting to create compact mathematical theories that can map between physical and conscious states. Computers could be used to discover these theories automatically.

Chapter 6 discusses theories that link consciousness to patterns in physical materials—for example, electromagnetic waves or neuron firing patterns. With physical theories the materials in which the patterns occur are critical—if the same patterns occur in different materials, they are not claimed to be linked to consciousness. Physical theories of consciousness are similar to scientific theories in physics, chemistry and biology.

Some people have claimed that information patterns are linked to consciousness, regardless of whether they occur in a brain, a computer or a pile of sand. The seventh chapter shows that this approach fails because information is not a property of the physical world and any given information pattern can be extracted from both the conscious and unconscious brain. Information theories of consciousness should be reinterpreted as physical theories of consciousness.

Other people believe that consciousness is linked to the execution of computations. They claim that some computations are linked to consciousness regardless of whether they are executing in a brain or a digital computer. Chapter 8 argues that computations cannot be linked to consciousness because computing is a subjective use that we make of the world. Computation theories of consciousness should be reinterpreted as physical theories of consciousness.

Chapter 9 explains how theories of consciousness can be experimentally tested. This can only be done on systems that we assume are conscious, such as normally functioning adult human brains. We can also use our theories of consciousness to make deductions about the consciousness of brain-damaged people, animals and robots. These deductions cannot be verified because we cannot measure the consciousness of these systems.

When we have discovered a reliable theory of consciousness we will be able to use it to modify and enhance our consciousness. For example, we could change the shape of our conscious body or increase our level of consciousness. Chapter 10 explains how we can use a theory of consciousness to identify the physical state that is linked to a desired conscious state. If we could realize this physical state in our brains, we would experience the desired conscious state. It will be many years before this will become technologically possible.

The eleventh chapter suggests how a reliable theory of consciousness could be used to create conscious machines and make believable deductions about the consciousness of artificial systems. Silicon brain implants and consciousness uploading are interpreted as forms of machine consciousness, and the chapter discusses whether conscious machines could threaten human existence and how they should be ethically treated.

The conclusion summarises the book, highlights its limitations and suggests future directions of research. The appendix lists the definitions, assumptions, lemmas and constraints.

The main text of this book is short and self-contained and can be read through without referring to the endnotes or bibliography. The endnotes contain more detailed discussions of individual points and full references to the scientific and philosophical literature.

2. The Emergence of the Concept of Consciousness

© David Gamez, CC BY 4.0 https://doi.org/10.11647/OBP.0107.02

2.1 Naive Realism

I am immersed in a colourful moving noisy tasty smelly painful spatially and temporally extended stream of things. During a nuclear explosion I see a grey mushroom cloud, hear a detonation, feel heat, touch wind and taste synthetic strawberry bubblegum in my mouth. I do not infer the presence of these things—they are just there before me as the world at this place and time seen from my perspective.

When Cro-Magnon man peered out of his cave he saw a bright pattern of green leaves, heard a river and tasted sweet-tart berries in his mouth. The green of the leaves was present to him, framing the entrance to his cave, just as the river was crashing and roaring to his left. No complicated theories about consciousness troubled Cro-Magnon man: the world was simply present to him. In this idealised naive and simple time people simply saw the world, unclouded by theories of perception.

When a child opens its eyes it does not see a collection of qualia1 or conscious representations: just a red balloon ascending into the warm summer sky.

Most modern adults most of the time have a direct relationship with the world around them. We are immersed in a world of colourful moving noisy tasty smelly things. As we slog through our workaday lives we are not philosophizing—the blue of my computer screen is the colour of an object in the world; the tinny speaker sound is part of the world. We go outside and see cold grey skies and are lashed by cold lashing rain.

For me at least, the colourful cheerful world is the most important thing there is. I long to drink in more of the visible audible tasty moving world. What I hope for in any afterlife is that some kind of a world will continue, ideally in a reasonably pleasant way. While one can make abstract ethical points about the value of life, its real value for me is this immersion in a sensuous world.

This relationship with the world is often called naive realism: an interpretation of perception in which we directly see the world and the world is as we see it. However, there is nothing naive or realistic in our everyday encounters with the world—‘naive realism’ is a convenient label that we use to contrast our everyday immersion in the world with other theories of perception.

I am standing in my sitting room staring dully through dirty net curtains at nothing in the street outside. I cannot see the body of my aunt. It is out there in the garage. I walk into the garage and open the blue plastic sack. Now I can see the body of my aunt.

When I look at my aunt’s body it appears as three-dimensional, although I can only see part of it at one time. From one perspectiveI can see my aunt’s grey lips and clouded eyes, but I cannot see her whole head or body. I have to move relative to her body to see her thin grey hair and the matted dried blood on the back of her head.

My aunt’s body changes independently of my interactions with it. Each time I return to the garage I observe subtle changes in colour as her body decays. Her body has an objective existence that can be systematically probed in different ways. I can perform chemical tests; I can measure its hardness and weight.

Other people cannot see the body of my aunt. The police cannot see it. Uncle Henry, on holiday in Tahiti, is staring at the gyrating buttocks of a young woman in a grass skirt. He is not looking at the body of my aunt.

Naive realism is not simultaneous and all-embracing access to every object in existence. We see a small number of the world’s objects from oneperspective. Objects have an independent existence that enables them to be perceived by other people. Different people seedifferent things. We can perceive the same object on multiple occasions. Objects can be in different statesat different times.

In our naively realistic encounters with the world we use the language of perception to indicate those things and those aspects of things that are present to us and to acknowledge that objects continue to exist when they are not being perceived. Instead of saying that my aunt’s body isthere, I talk about perceiving my aunt’s body to indicate that it is currentlypresent to me. Uncle Henry is not perceiving her body: it is not present to him in Tahiti.

Perception is similar to a bubble that we ‘carry around’ with us that contains the objects that are currently present to us. I will call this a bubble of perception. We are immersed in our bubbles of perception. When an object appears in my bubble of perception I see it from a perspective that is centred on my body.2

A visual representation of a bubble of perception is shown in Figure 2.1b. This is inaccurate because it shows the person’s body from a third-person perspective, whereas we experience our bubbles of perception from the inside—we look out from our bodies onto the world. This illustration has the further limitation that it only shows the visual aspect of a bubble of perception. Bubbles of perception also include tastes, sounds, smells, body sensations and emotional states.

In naive realism objects have the properties that we perceive them to have. The plastic sack is blue; my aunt’s body is cold; her clothes have a mothball and urine odour. Objects have these properties independently of whether they are inside or outside a bubble of perception. The plastic sack continues to be blue when it is in the garage and not being perceived by anyone (Figure 2.1a).

I sit in the kitchen and imagine my aunt’s body in the garage. Now the contents of the sack are fleeting and unstable, colours are washed out and the smell of moth balls and urine is not present. I dream of my aunt’s body. This is more vivid than imagination, but my aunt’s face changes from moment to moment, and it is difficult to inspect details and maintain consistency over time. I go for a walk in the forest and eat a mushroom. One hour later my aunt rises from the ground before me: her eyes are dark geometric spirals; her hair is a writhing mass of white maggots.

Figure 2.1. Visual representation of a bubble of perception. a) Domestic scene. In naive realism the sack in the garage continues to be blue when no-one is looking at it. b) A visual representation of a bubble of perception. This uses a third-person perspective to represent our sense of inhabiting a body and looking out at a world. Although this is substantially different from an actual bubble of perception, which we experience from inside our bodies, it is the best way that I have found of depicting a bubble of perception. Image © David Gamez, CC BY 4.0.

We no longer believe that imagined, dreamt or hallucinated objects are objectively present in a second spiritual world. It no longer makes sense to say that we perceive imagined, dreamt or hallucinated objects. This is particularly true now that perception is associated with theories about electromagnetic waves, sound vibrations, and so on. To address this issue I will replace ‘bubble of perception’ with the more inclusive term ‘bubble of experience’, and distinguish between two types of bubble of experience:

Online bubbles of experience are connected to the world: their states change in response to changes in the world and detailed information about the world can be accessed on demand. They typically have vivid colours, clear sounds, strong odours and intense body sensations. In an online bubble of experience objects are stable, we can view the same object on multiple occasions and people generally agree on an object’s properties. We are immersed in online bubbles of experience when we perceive and interact with the world.Offline bubbles of experience are not connected to the current environment, although they might correspond to past or future states. They are often unstable, low resolution and low intensity. Colours are washed out; smells, tastes and body sensations are rarely present. Offline bubbles of experience are typically weakly perceptual—we cannot interact with objects in a systematic way, and it can be difficult to repeatedly view the same object from multiple perspectives or to examine small details. People typically do not agree about the objects that they encounter in offline bubbles of experience. We are immersed in offline bubbles of experience when we dream, remember, hallucinate and imagine.

A bubble of experience can have a mixture of online and offline contents. When I hallucinated my aunt the forest was an online component of my bubble of experience; the aunt and maggots were offline.3

2.2 Invisible Explanations

The flowers in my living room appear in my online bubble of experience on multiple occasions. I can see them from multiple perspectives and uncover more of their properties. They appear in other people’s bubbles of experience. The flowers are part of an independent world, which is often called the physical world.

The physical world has regularities. If I throw a pig out of a window, its pink colour and screams move together and its rate of acceleration can be calculated using a simple equation. If I mix one part glycerine with three parts nitric acid, I obtain an explosive mixture that can alleviate angina.

We explain these regularities by postulating the existence of invisible objects and properties in the physical world. These do not appear in our bubbles of experience—we believe in their existence because they improve our ability to make predictions about objects in our bubbles of experience.

X-rays are invisible waves that were posited to explain the appearance of patterns on photographic plates. These patterns can easily be explained if there is a form of radiation that cannot be perceived with the human eye. Our belief in X-rays was strengthened by the development of other methods for detecting them. Only the effects of X-rays appear in our bubbles of experience—the rays themselves are invisible.

Visible and invisible gods are often used to explain regularities in our bubbles of experience. A statue of Tlaloc might be considered to be Tlaloc himself, something that Tlaloc inhabits to some extent or just a representation of Tlaloc. Sometimes the Judeo-Christian god is depicted as a beardy bloke floating in the clouds; more often he is assumed to be invisible.

Prayers, sacrifices and moral rectitude encourage the gods to bestow rain, fertility and a good harvest on their virtuous subjects (see Figure 2.2). Murder, incest and eating prawns anger the gods, who inflict earthquakes, floods and infertility on people who stray from the path of righteousness.

Figure 2.2. The presence of an invisible god explains regularities in the visible world. a) Worshippers of Tlaloc offer up sacrifices and prayers for rain. b) The psychology and actions of the invisible god explain the appearance of the rain. Image © David Gamez, CC BY.

Early astronomers explained the regular movements of the heavenly bodies by claiming that they are embedded in concentric crystalline spheres. These spheres were invisible to human observers on Earth, but they probably believed that they could have touched them if they could have reached them.