Are you your brain? Steven Rose s.p.r.rose@open.ac.uk.

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Transcript of Are you your brain? Steven Rose s.p.r.rose@open.ac.uk.

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 timeAbstract thoughts, numbersThe idea of godLogical 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 GodFor - heft them - Pound for PoundAnd they will differ - if they doAs Syllable from Sound Emily Dickinson, c 1862

Three Neuro Decades1990s – 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??

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 sites for everything

Mathematical ability

Romantic love

Moral judgments

Voting tendency

Terrorist thoughts

Psychopathy

And of course consciousness

Neurolove

So what’s the problem?

Overestimates the power of fMRIBlood flow surrogate measureTimescale (seconds )too longVolume too great :50mm3 contains5m 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.’