Transcript Neuroethics: The State of the Art

Neuroethics Beyond
Genethics
EMBO/EMBL Nov 3-4, 2006
Adina Roskies
Dartmouth College
and
Sydney University
Neuroethics:
 The ethics of
neuroscience
 The ethics of practice
 Ethical implications of
neuroscience
 The neuroscience
of ethics
Ethics of
Neuroscience
Neuroscience
Of Ethics
Early thoughts on neuroethics
“The question at issue here is how far the
knowledge that we have about our brain gives us
a new conception of ourselves, a different
representation of our ideas, our thoughts and the
dispositions that intervene when we make
judgments. With regard to moral judgments, in
fact, it is fundamental. The knowledge that we are
now in the process of piecing together about the
human brain ought to allow us to have a clearer
idea -- I am perhaps overly optimistic -- of the
direction in which we wish to see human society
develop…”
--J.P. Changeux
Is neuroethics a distinct field?
 Is neuroethics a
discipline in its own
right?
 Do the problems it
raises differ from
those in genethics?
Ethics of
Neuroscience
Neuroscience
Of Ethics
The ethical space
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
personhood
and the self
access
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Overlap
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
personhood
and the self
access
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Genethics beyond neuroethics
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
personhood
and the self
access
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Neuroethics beyond genethics
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
personhood
and the self
access
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Finding the neural correlates
of consciousness
MCS and PVS
MCS: minimal awareness of
self
PVS: no awareness of self
Even PVS patients may appear
somewhat normal
MCS:112,000-280,000 in USA
PVS: 14,000-35,000
(Embo reports,2005)
Schiavo case
 PVS
 Support eventually
terminated
 Public focus
 Autopsy revealed
massive irreversible
damage
Metabolism in normal and
vegetative state
normal
PVS
PVS after
recovery
Laureys, 2006
Preserved brain activity in
MCS
Case 1
Case 2
normals
Schiff et al (2005): 2 men in MCS show brain
activity to familiar audio track, but many differences
Brain damage and
consciousness
 Lots of brain activity activity occurs
during sleep, without awareness etc.
 Despite this:
“The findings show that some people that
doctors had previously declared to be in a
Persistent Vegetative State (PVS) are still
conscious.”
(commentary on the web)
More recent studies
Owen et al., 2006
Ethical implications
 Methods to assess awareness in braindamaged patients
 Methods can be developed to
communicate with patients physically
unable to respond
 May provide patients with more
autonomy, but leaves us with ethical
choices to make, nonetheless
Neuroethics beyond genethics
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
personhood
and the self
access
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
What is a person?
 Personal identity
 Neuroessentialism (“We are our brains”)
 Psychological or brain-based criteria seem
important
 Do alterations in brain function alter personal
identity?
 The self
 What is the representation of ‘self’?
 Is the self an illusion?
Personhood
 On the basis of philosophical disputes
and neuroscientific data, Farah and
Heberlein (AJOB Neurosciences,
forthcoming) argue against personhood
as a natural kind
Naturalizing personhood
“The real contribution of neuroscience to
understanding personhood may be in
revealing not what persons are, but rather
why we have the intuition that there are
persons… instead of naturalizing the concept
of personhood by identifying its essential
characteristics in the natural world,
neuroscience may show us that personhood
is illusory, constructed by our brains and
projected onto the world”
(Farah & Heberlein, AJOB Neurosci, forthcoming)
Our person-intutions
 2 different networks
 Person-network (the social brain): Automatic,
fast, based on simple perceptual features, issues
in yes/no judgments
 Object-network: More abstract, analytical,
higher cognitive areas; issues in graded
judgments
 Suggest abandoning the concept of
personhood for ethics
What is a person?
 An important ethical concept
 Doesn’t have to be a natural kind
 Neuroscience can help put it in
perspective; we can choose what
criteria we think are more important
Neuroethics beyond genethics
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
access
personhood
and the self
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Decision-making in nonhuman
primates
 Reward circuitry
 Midbrain dopaminergic
system
 VMPFC codes primary
reinforcers and reward
associations in changing
circumstances
 Integrative areas in
DLPFC and parietal cortex
Neurobiology of reward
Similar areas are active in humans in
neuroimaging of decision-making tasks
 Reward/Emotional circuitry:
 VMPFC/OFC: associating outcomes with reward; integrate
sensory and limbic signals
 Striatum: critical component of dopaminergic reward system
 Amygdala: predictive of bad outcome
 Insula: associated with risk, punishment
 ACC: conflict monitoring, risk
 ‘Cognitive’ regions:
 DLPFC: online manipulation and integration of decisionrelevant information
 Posterior parietal cortex: calculation
The problem
 Decisions, choices, actions are generally
thought to be freely willed
 Science reveals them, or threatens to reveal
them, to be mechanistically or physically
intelligible.
 This mechanistic view challenges our
intuitions about freedom and its conceptual
partner, moral responsibility.
Free will:
“By monitoring the signals produced by
appropriate neurons, an experimenter can
predict and even influence what a monkey
will choose…Ethics, not theory, would
preclude an investigator from obtaining the
same relationship with a human agent. Can
this ability to predict and influence be
reconciled with a belief in freedom and
responsibility?”
• Schall, Nature Reviews Neuroscience, 2001
Rethinking freedom and
responsibility
 The old view:
Freedom is
 Ability to do otherwise
 Absence of constraint
Moral responsibility
 We have intuitive senses of when people are
appropriate objects of reactive attitudes of
praise, blame, respect, etc. for their
actions.
 The intuitions seem to involve a conception
of free action
The regress of being able to do
otherwise
 To be free is to be able to:
 Act otherwise
 Choose to act otherwise
 Our brains (not our selves) do the choosing
 But
 Our brains are our selves
 We must become comfortable with mind as
mechanism
The neuroscience of ethics
 Recasting freedom as self-governance:
 What mechanisms underlie our ability to
control our actions; what failures undercut
that ability?
 Can we make sense of freedom as selfregulation?
The neurobiology of
responsibility
 Cognitive demand:
 Appropriate representation of moral facts
 Representation of self as rational agent? An
intentional agent?
 Control demand:
 Appropriate motivational structures
 When a person is in control of his actions, his
actions depend on his motivational states
 Appropriate links between cognitive and
motivational structures
 Effective mechanisms of inhibition
Neuroethics beyond genethics
neuroethics
genethics
decision-making
and freedom
consciousness
moral cognition
access
personhood
and the self
treatment
consent
normalcy and disease
discrimination
distributive justice
enhancement
future
generations
Neuroimaging results
Greene et al., 2001
 Overlap with areas involved with general decision
making
 Activity in regions implicated in emotion, especially in
‘personal’ moral judgments
Difficult - easy personal dilemmas
Greene et al., 2004
 High RT(counter-intuitive) - low RT (intuitive)
‘personal’ judgments
 Override emotional bias with more abstract thought
What does this say about the
nature of morality?
 Mechanistic?
 Does it correspond to something out in
the world?
 Our intuitions don’t necessary track
morally-relevant features of situations
 An artifact of how we are wired up?
 Do blame and punishment make sense?
Retributivism vs. utilitarianism.
Is neuroethics a distinct field?
 Do the problems
neuroethics raises differ
from those in
genethics?
 Is neuroethics a
discipline in its own
right?
Ethics of
Neuroscience
Neuroscience
Of Ethics
Yes, distinct enough
 Neuroethics raises some novel questions
 Even when questions are similar, they have
distinctive aspects
 To some extent, disciplines are socially
constructed
 Neuroethics deals with sophisticated
methodologies and a complex body of data and
theory, and requires people trained in both
neuroscience and ethics to adequately assess the
evidence
 Nonetheless, we shouldn’t overlook the debt
neuroethics has to bioethical thought that
precedes it.