Are you your brain?

advertisement
Are you your brain?
Steven Rose
s.p.r.rose@open.ac.uk
St. Augustine’s Questions
 How does the brain/mind encompass:
Vast regions of space and time
Abstract thoughts, numbers
The idea of god
Logical propositions and false
arguments.
Brain versus Mind?
(Emily Dickinson, 1862)
 The Brain - is wider than the Sky  For - put them side by side  The one the other will contain -
 With ease - and you -beside
 The Brain is just the weight of God
 For - heft them - Pound for Pound
 And they will differ - if they do
 As Syllable from Sound

Emily Dickinson, c 1862
Three Neuro Decades
 1990s – decade of the brain
 2000s – decade of the mind
 2013 - EU announces €1 billion for a ‘human brain
project’ to build a virtual brain through computer
simulation.
 Obama announces BRAIN – a $3billion project tracking
all the trillions of connections between nerve cells in
the human brain (starting with mouse!) paid for by NIH,
DARPA etc
 Will help ‘epilepsy, depression, schizophrenia, autism,
dementia..stroke, cerebral palsy….’ (and the military)

And the reach of the neurosciences
grows ever longer
 Neurolaw
 Neurowar
 Neuroeconomics
 Neuromarketing
 Neuroaesthetics
 Neuroeducation
 Neuroethics……….
 And neuroculture??
But something seems to be going wrong
 Levels of diagnosed psychic distress grow ever higher.
 Huge scepticism over DSM5
 No new drugs for depression, schizophrenia etc
 Over 2012-13 many big pharma companies withdraw
from CNS research to the safer ground of genomics
 So is there something rotten at the heart of the
neurotechnoscience enterprise?
The core assumption of modern neuroscience
 Minds and consciousness are brain processes
 To cure the mind one must cure the brain
 But these claims are not uncontested
Brains and Minds:
Four philosophical propositions
 Dualism: Body/brain …. Soul/mind two
different types of stuff
 Identity: Brain/mind are two aspects of the same
phenomenon
 Epiphenomenalism: Mind emerges from brain
 Mechanical materialism: Minds are ‘nothing but’ brains
 NOTE! I am not going to agree with any of these!
Not all neuroscientists have been
hard materialists
 Descartes and the pineal gland
 Sherrington’s enchanted loom
 Sperry’s downward causation
 Eccles and the liaison brain – the god of
 the synapses
Some modern Dualists
 Edelman – you are your brain.. plus free will!
 Libet - the 350msec gap and the brain’s ‘free won’t’
 And some closet dualists – Dawkins, Pinker
 ‘only we can rebel against the tyranny of our selfish
genes
 ‘if my genes don’t like it they can go jump in the lake’
19th century materialists
 Thomas Huxley: Mind is to brain like the whistle to the
steam train
 Moleschott, Vogt et al: The brain secretes thought like
the kidney secretes urine; genius is a matter of
phosphorus
Modern materialists
 Crick – ‘you are nothing but a bunch of neurons’
 Kandel – ‘you are your brain’
 Silva – ‘ruthless reductionism’
 Gazzaniga – ‘the ethical brain’
 LeDoux – ‘synaptic self’
 Changeaux – ‘neuronal man’
And some philosophers follow suit
 Churchland – neurophilosophy and ‘folk psychology’
 Dennett – ‘consciousness explained’
Some problems for materialists
 Subjective experience and qualia – how does conscious
experience emerge from brain chemistry/physics
 How did consciousness evolve (Darwin v Russell Wallace)
 Free will and determinism – ‘my brain made me do it.’
But if this were true
 Minds wouldn’t matter at all – we only need think brains
 But minds do matter; we have self-awareness; minds
have reasons, are conscious and are evolved properties
of humans, with Darwinian survival functions. These are
irreducible properties.
 So we also have to assume that although there is a
qualitative jump between us and our nearest
evolutionary relatives (chimps, bonobos) that these and
maybe other big brained animals have rudimentary
forms of consciousness (Damasio; Nagel)
fMRI promises to solve the mind/brain
question
Brain sites for every thought and feeling
‘A happy marriage between fMRI and experimental
psychology can bridge the divide between mind and
brain’
Phrenology – external and internal
‘Psychopathic Brains?’
The Right and the Good: Distributive Justice
and Neural Encoding of Equity and Efficiency*
 Subjects making decisions re allocating meals to
children in Ugandan orphanage
 Quandary: to share limited food equally (equity) but
inadequately, or giving enough food to chosen few
(efficiency).
 Result: ‘Insula encodes inequity, putamen efficiency’

*Hsu et al Science 320, 1092-5, 2008
“Brain Fingerprinting”
 “How do we determine if a person is a terrorist or spy?
There is a new technology, that for the first time, allows
us to measure scientifically if specific information is
stored in a person’s brain. Brain Fingerprinting
technology can determine the presence or absence of
specific information, such as terrorist training and
associations. This exciting new technology can help….
 [by EEG recordings]
discover if a person:
 Has committed terrorist acts
 Has been trained as a terrorist
 Is a terrorist leader…. (from the company website)
Brain sites for everything
 Mathematical ability
 Romantic love
 Moral judgments
 Voting tendency
 Terrorist thoughts
 Psychopathy
 And of course consciousness
So what’s the problem?
 Overestimates the power of fMRI
 Blood flow surrogate measure
 Timescale (seconds )too long
 Volume too great :50mm3 contains
5m neurons, 50b synapses 22km dendrites,
220km axons!
 Mistakes activity for location
Romantic love, psychopathy – and a
dead salmon
But there are more fundamental
problems
 These studies reify processes,
thoughts and judgements – turning
concepts from the social realm
(efficiency, terrorism, psychopathy..)
into localisable ‘things’ in the brain
So here’s a thought experiment
Let’s invent a cerebroscope
The cerebroscope
 Detects the activity of every neuron in my
brain millisecond by millisecond
The cerebroscope
 So it will interpret my brain activity as
Steven reading this caption, giving this
seminar?
•Or will it?
A more dynamic cerebroscope
 Not only reads the present state of my synapses but has
plotted them millisecond by millisecond from their
formation.
 So could you now ‘read off’ my mind from my brain?
I still think the answer is no
The experience may impose a unique
pattern in my synapses etc, but can that
pattern in turn be read as unique to the
experience?
The pattern may show I am talking, but
will it show the content of my speech?
Because
 There’s more to the brain than wiring diagrams and
neurotransmitters
 Modulators, field effects etc
 The brain is in the body
 hormones, immune system
But more fundamentally:
brain and body are part of the biosocial world in which we are
embedded
Minds are not Brains
Minds are to brains like legs are to walking.
We don’t say ‘my legs are walking’ but that we use our
legs to walk
Similarly, it is we who have minds and consciousness, and
we use our brains to think
Nor are our minds in our bodies
(as St Augustine suggested)
 Maybe as philosopher Gilbert Ryle suggested we
don’t have minds (noun); instead we mind (verb).
• Minding is a hybrid, not a reified brain process, though it
requires the brain, but an ever-changing relationship
between an individual and the physical social cultural and
historical world;
 Consciousness is relational, the dynamic product of
present and past brain and body activity, life history and
social context, a process, not a reified ‘thing.’
Download