1. Ghost machine

Question 1

How do neurons work in the brain?

Answer 1

• Consists of about 100 billion neurons
• Each neuron can form between 5,000 and 200,000 connections with other neurons.
  These interconnected systems are organised into very complex and powerful information processing networks

Question 2

What are the levels of organisation in the brain?

Answer 2

• Molecules (1 Å)
• Synapses (1 μm)
• Neurons (100 μm)
• Networks (1 mm)
• Maps (1 cm)
• Systems (10 cm)
  CNS (1m)

Question 3

What are the schools of thought?

Answer 3

· There are diverse schools of thought in Philosophical Psychology
· These are based on positions taken in relation to fundamental issues
· The schools of thought are often inter-related and include
– Dualism
– Materialism
– Functionalism
– Behaviourism
– Reductionism …and many others!

Question 4

What is Cartesian Dualism?

Answer 4

· The relationship between the mind and the body has been an important area in philosophy and science for many hundreds of years.
· Cartesian Dualism: Descartes recognised that mind and brain were inextricably linked, but also believed that they were separate.
He relegated the body to the status of a marvellously constructed machine

Question 5

What is behaviourism?

Answer 5

· Behaviour can be researched scientifically without recourse to inner mental states.
· – Learning organisms are ‘black boxes’ that somehow convert inputs into outputs. There is no need to understand how the black box does it.
· – It is a form of materialism, denying any independent significance for the mind.
– Free will is illusory, and that all behaviour is determined by a combination of forces (environment, genetics etc. through association or reinforcement).

Question 6

What is ‘Occams Razor’?

Answer 6

– A logical principle: one should not make more assumptions than the minimum needed. The simplest explanation is the best.

Question 7

What is Materialism ?

Answer 7

– The only thing that can exist is ‘matter’
– All things are composed of matter and all phenomena are the result of material interactions
– The construct we call ‘the mind’ must therefore be a property of matter (the brain).

Question 8

What was Dennet’s view on consciousness?

Answer 8

· Dennets dismisses the notion of a ‘Cartesian theatre’…
“In a cobbled-together collection of specialist brain circuits, which . . . conspire together to produce a . . . more or less well-designed virtual machine . . . By yoking these independently evolved specialist organs together in common cause, and thereby giving their union vastly enhanced powers, this virtual machine, this software of the brain, performs a sort of internal political miracle: It creates a virtual captain of the crew . . . “

Question 9

Monism to dualism?

Answer 9

• Substance (Cartesian) Dualism: Mind and matter fundamentally different
• Identity Theory: Mind = Matter in an absolute sense
  There are a spectrum of views between Substance Dualism and Identity Theory

Question 10

How did dualism change?

Answer 10

• Property dualism: Even if mind comes from brain, subjective experience has properties that cant be reduced to brain states
• Identity Theory: Mind = Matter in an absolute sense
  Science dismisses substance dualism because of the hopelessly insoluble problem of the Cartesian Gap…but there are other forms of dualism

Question 11

What are the arguments for property dualism?

Answer 11

• The arguments…
• ‘Non-reductive physicalism’: Although there are low-level physical states that cause higher-level states, one can’t explain higher level effects in terms of lower-level causes. So, mind states do come from brain states, but we can’t explain mind states in terms of brain states.
• They have ‘properties’ that are distinct from the properties of brains
• Subjective experience is fundamental: We know that mental states are real because we experience them
• (This is suspiciously close to Cartesian ideas that separate the observer and the observed)

Question 12

What is functionalism?

Answer 12

• “The mind is the software of the brain” Ned Block (1995)
  -A form of property dualism
  • Developed as an answer to the mind-body problem in response to behaviourism.
  • Mental life can be explained in terms of higher-level functions.
  • Assumes that information processing occurs at a level of abstraction that does not depend on the physical composition of a system
  • In theory, all functional systems can be implemented in any hardware

Question 13

Arguments against functionalism?

Answer 13

· Taken to its logical conclusion, functionalism argues that in theory, even consciousness can be implemented in any computer
· John Searle (1980) argues against this idea:
– Emulating the functional behaviour of the brain, or some part of it, is insufficient grounds for attributing to a machine or computing device the cognitive states such as those experienced by conscious beings like ourselves
– Such devices could never possess such states solely as a result of having the appropriate formal properties, or to put it another way, simply by ‘running the right program’.
– He proposed a ‘thought experiment’ based on the Turing test…

Question 14

What is the Turing test?

Answer 14

· Can machines simulate intelligent behaviour? Alan Turing devised a test in the 1950’s
· A person converses ‘virtually’ with another person (A) and a computer (B) but does not know the true identity of either
· The machine tries to cause the interrogator to mistakenly conclude that the machine is the other person
The other person tries to help the interrogator to correctly identify the machine.

Question 15

Searle’s thought experiment: The Chinese room?

Answer 15

• Imagine a native English speaker who knows no Chinese locked in a room full of boxes of Chinese symbols (a database) together with a book of instructions for manipulating the symbols (the program).
• Imagine that people outside the room send in other Chinese symbols which, unknown to the person in the room, are questions in Chinese (the input).
• Imagine that by following the instructions in the program the man in the room is able to pass out Chinese symbols which are correct answers to the questions (the output).
  Against functionalism: The program enables the person in the room to pass the Turing Test for understanding Chinese but he does not actually understand Chinese. Computers merely use rules to manipulate symbols, but have no understanding of meaning or semantics.

Question 16

What is neurophysiology?

Answer 16

• “The goal of science is not to open the door to everlasting wisdom, but to set a limit on everlasting error” Galileo
• What is Neurophilosophy?
• “Neurophilosophy arises out f the recognition that at long last, the brain sciences and their adjunct technology are sufficiently advanced that real progress can be made in understanding the mind-brain…[it] focuses on problems at the intersection of a greening neuroscience and a greying philosophy.” Churchland (2002)
  Neurophilosophy seeks to explain the mind in terms of observable evidence from the physical world that is obtained using scientific methods.

Question 17

What is reductionism?

Answer 17

• Reductionism: The principle that complex phenomena can be explained in terms of the interactions between simpler phenomena
• Neurophilosophy argues that reductionism is essential for understanding the mind in terms of the brain.
  The aim of this course (and the other courses in this stream) is to explain mental phenomena in terms of the physical events that take place in the brain.

Question 18

Churchland and reductionism?

Answer 18

· “Neuroscientists would be silly to make a point of ignoring all behavioural data, just as psychologists would be silly to make a point of ignoring all biological data”
· “If you want to understand how a thing works, you need to understand not only its behavioural profile, but also its basic components and how they are organised to constitute a system”
· “Insofar as I am trying to discover macro-to-micro explanations, I am a reductionist”
“So far as neuroscience and psychology are concerned, my view is simply that it would be wisest to conduct research on many levels simultaneously, from the molecular, through networks, systems, brain areas, and of course behaviour”.

Question 19

What is folk theory?

Answer 19

· Our common sense understanding of reality (including our understanding of the ‘self’) is often misguided.
· Science overturns our common sense understanding…
- Mendelian inheritance to genetics
- Classical optics to quantum optics
- The earth is not flat (even though this is what our subjective experience tells us)!
- Surfaces appear to be solid but there is mostly space between the atoms and molecules that it is made of!
· Churchland argues that Functionalist psychology is actually ‘folk’ psychology: Notions of mind based on our common sense, everyday, subjective understanding of mental life.
· Folk psychology is based on concepts that are based on language (syntax and the semantics of ‘beliefs’ and ‘desires’).
· Eliminative materialism suggests that folk psychology (functionalism) will
eventually be replaced by rational, scientific (not subjective) explanations of mind in terms of neuroscience.

Question 20

What is Inter-theoretic reduction?

Answer 20

· A process that explains the relationship between two theories at different levels
· Explaining a ‘high level’ theory in terms of a more fundamental lower-level theory.
· Neurophilosophers / neuroscientists (but not functionalists) think that psychological phenomena can be explained in terms of neural function through the process of inter-theoretic reduction.
· Inter-theoretic reduction is remarkably common across many disciplines science.
There are many examples where general descriptions of phenomena are explained in terms of physical causal mechanisms

Question 21

Eliminative materialism: Cogito ergo sum?

Answer 21

· Takes inter-theoretic reduction to its logical conclusion
· The radical claim that our ordinary, common-sense understanding of the mind is deeply wrong and that some or all of the mental states posited by common-sense do not actually exist.
· Behaviour and experience can only be adequately explained on the biological level
· There are no mental states, just brain states.
· This seems counter-intuitive: Surely we have mental states because we actually experience them?
The argument from subjective experience is the commonest argument against eliminative materialism

Question 22

Eliminative materialism: Sperry split brain?

Answer 22

· Another example of how our introspections can be wrong
· The notion of a unified ‘self’ is also a percept. Could it be an illusion?
• Sperry: The divided self
– Experiments completely changed our understanding of consciousness
and the brain
– Patients with epilepsy underwent surgery to prevent epileptic seizures
from spreading from one hemisphere to the other via the corpus callosum
· – Callosal transection: Corpus Callosum was severed surgically
· – Patients seemed remarkably normal after recovery from surgery
· – Controlled psychological testing revealed two independent streams of
This suggests that our subjective experience of a unified self (and probably many other introspections about out mental states) is wrong!

Question 23

Inter-theoretic reduction: Example 1

- Laws of Mendelian Inheritance reduce to Genetics ?

Answer 23

· Laws of inheritance derived by Gregor Mendel (19th century Austrian monk)
· Conducting plant hybridity experiments.
· Between 1856 and 1863, he cultivated and tested some 28,000 pea plants.
· His experiments brought forth two generalizations which later became
known as Mendel’s Laws of Heredity or Mendelian inheritance.
· These laws are now obsolete because they are explained entirely by classical genetics.
· The laws don’t exist separately from their mechanisms. They are explained in terms of these mechanisms.
In this example a higher level theory is reduced to (and eliminated by) a lower level, more fundamental theory that explains causal effects.

Question 24

Example 2

-Classical Optics reduces to Quantum Optics ?

Answer 24

· Classical optics is concerned with the geometry of light (how it can be refracted by transparent material etc).
· Classical Optics: Light behaves like a wave
– Johannes Kepler (1604): The eye focuses light; light moves in a straight line
– Isaac Newton’s Opticks (1704): Laws that describe how light is refracted
· Quantum Optics: Light behaves like a particle
– Max Planck (1899): The exchange of energy between light and matter only
occurred in discrete amounts he called quanta
Light is electromagnetic radiation, just as mental events are neural events
Again - a higher level descriptive theory is reduced to (and eliminated by) a lower level, more fundamental theory that explains causal effects.

Question 25

Example 3

- An example from behaviours and brains?

Answer 25

• Learning reduced to neural information processing
  · Rescorla-Wagner: Very clear and reliable higher level explanation of how various factors account for learning during classical conditioning
  · David Marr proposed a theory of how Hebbian synapses work in the cerebellum
  · We now have an understanding of how CS, US, CR and UR information is processed by synapses that learn within cerebellar neurons
  · Learning is described by Rescorla-Wagner, but learning is the processing of this information in neural pathways.
  In the case of this kind of classical conditioning, learning theory is reduced to a neural theory (for which there is empirical evidence)

Question 26

What is Emergence?

Answer 26

• Triani and Tuci (2009) : What do ants and neurons have in common?
• “An ant is part of a colony, much as a neuron is part of the brain.
  · An ant cannot do much in isolation, but a colony is a highly resilient adaptive system. Similarly, a neuron is individually able just of limited interactions with other neurons, but the brain displays highly complex cognitive processes.
  · In other words, both ants and neurons behave/act in harmony with other conspecifics/cells to accomplish tasks that go beyond the capability of a single individual.”
• “while no individual [ant] is aware of all the possible alternatives, and no individual possesses an explicitly programmed solution, all together they reach an ‘unconscious’ decision. This is particularly true also for neural systems, where the relevance or the meaning of the self-organised pattern is not found at the individual level, but at the collective one.”
  Some have suggested that ‘swarm intelligence’ operates as much in the brain as in other biological systems.

Question 27

Strong and weak emergence?

Answer 27

• Weak emergence: “…the high level phenomena emerge from the low level domain, but the truths concerning that phenomenon are unexpected [but still deducible] given the principles governing the low level domain….”
  Strong emergence: “……a high-level phenomenon is strongly emergent with respect to a low-level domain, but truths concerning that phenomenon are not deducible, even in principle, from truths in the low-level domain.”

Question 28

Irreducibility and emergence?

Answer 28

• Some have suggested that consciousness is an emergent property.
• Weak Emergence, Reductionism and Neurophilosophy:
  · Churchlands approach resonates with weak emergence.
  · Even though the whole is greater than the sum of its parts, it is possible to apply reductionist approaches so that the whole can be explained in terms of the parts.
  · They argue that emergent consciousness could be explained using reductionist approaches.
  -Strong Emergence and Irreducibility:
  · The whole emerges from the sum of its parts, but it is impossible to ‘reverse engineer’ to explain the whole in terms of its parts.
  · It has qualities that cannot be traced to the systems components
  This argument is often used against Churchlands reductionism.