Transcript Metody Inteligencji Obliczeniowej

Are we automata?
Włodzisław Duch
Department of Informatics
Nicolaus Copernicus University, Toruń, PL
Google: W. Duch
Self, intersubjectivity and social neuroscience, Torun, 26.09.2007
Who am I?
Quis ego et qualis ego?
Who am I and what kind of man am I?
St. Augustin (400 ac.)
What is the self?
Where then is this self, if it is neither in the
body nor the soul?
Pascal (1670)
How can we answer such questions?
Your are nothing else but a bunch of
neurons (Crick).
You are your synapses (LeDoux).
Is that a satisfactory answer? Not for all ...
If “I” = brain, then “I” do not exist.
I am then an automaton!
Traditional view
“I” decide in a conscious and free way, I am responsible for
Popper & Eccles in “The Self and Its Brain” (1977) think that self can’t
be just the brain, going back to the idea of souls animating bodies.
The illusion of “ghost in the machine”, or homunculus, is very strong.
S. Pinker: Tabula Rasa. The modern denial of human nature, 2002.
• Tabula Rasa (J. Locke)
• Noble savage (J.J. Rousseau)
• Ghost in the machine (Descartes)
Ancient view
Gilbert Ryle, The concept of mind, Univ. of Chicago Press (1949)
Is there a ghost in the machine? Or is mind a product of the brain?
Is there a horse inside the steam train?
Mind is not a thing, it is a process, succession of brain states.
Bible: psychosomatic unity of human nature.
Duch W (1999) Soul & spirit, or prehistory of cognitive science.
Kognitywistyka 1 (1999) pp. 7-38
Soul, spirit: dozens of meanings!
Things do not move by themselves, bodies are animated by spirits/souls.
Egyptians: 7 immortal souls, including shadow and personal name!
Aristotle (De anima) and St Thomas (Summa Theologica):
3 souls: vegetative or plant soul (growth), an animal soul (response),
philosopher’s soul (mind) – but these concepts lost their reference.
Early development
• Thomas Hobbes, Human Nature, 1651: For what is the
heart but a spring; and the nerves but so many strings; and the
joints but so many wheels, giving motion to the whole body.
• “Will” is just a verbal label we use to describe the attractions and
aversions we experience while interacting with the environment.
• Descartes, 1637: animals are automata, but men has soul.
• David Hartley, „Observations on Man” (1749): brain damage,
neurological problems lead to changes in perception and
thinking. Sensory experience are caused vibrations in the nerves.
reaching the brain and causing vibrations in the “infinitesimal,
medullary particles,” which cause sensations and ideas.
• Thomas Reid, „Inquiry into the Human Mind on the Principles
of Common Sense” (1764), „Essays on the Intellectual Powers
of Man” (1785) & „Essays on the Active Powers of Man” (1788):
mind has 43 faculties, but all different aspects of the same substance.
Neurologists
Thomas Laycock (1812–1876): Mind and Brain, Or, The Correlations of
Consciousness and Organisation (1860), reflexes in the seat of soul!
“... the brain, although the organ of consciousness, was subject to the
laws of reflex action, and that in this respect it did not differ from the
other ganglia of the nervous system. I was led to this opinion by the
general principle, that the ganglia within the cranium being a continuation
of the spinal cord, must necessarily be regulated as to their reaction on
external agencies by laws identical with those governing the functions of
the spinal ganglia and their analogues in the lower animals.
Fascinating history of acknowledging that automatisms are not only in the
spine but also in the brain is described in J. Miller, Going unconscious.
New York Review 42(7), 1995.
I.M. Sechenov, Brain reflexes (Refleksy golovnago mozga ,1866):
all conscious & unconscious acts are reflexes in terms of their structure;
subversive to public morals and social order, Sechenov was indicted.
More history
In 1873 Sir John Ericksen, Surgeon Extraordinary to
Queen Victoria: “The abdomen, the chest, and the
brain will forever be shut from the intrusion of the
wise and humane surgeon”.
T.H. Huxley, On the Hypothesis that Animals are
Automata, and its History (1874):
“... the feeling we call volition is not the cause of a voluntary act, but the
symbol of that state of the brain which is the immediate cause of that
act. We are conscious automata ... “
William James, Does 'Consciousness' Exist? (1904)
Pure monism:
... primal stuff or material in the world, a stuff of which everything
is composed, ... we call that stuff 'pure experience‘.
...the stream of thinking ... consist chiefly of the stream of my breathing.
Automatisms
Marshall Hall (1832): reflexes only in the spine, not in the brain, the seat
of soul, sensory experiences require consciousness, function of soul.
Benjamin Carpenter (1874): experiments of Jamesa Braida with
hypnosis (cured everything) shows cerebral automatism. Perceptual
system almost completely operates outside of conscious awareness.
Mechanism of thought also operates largely outside awareness.
These positive unconscious automatisms were forgotten when Freuda
came with his id, ego and superego ideas, that may be roughly apped
to the triune brain of MacLeana (brain stem, limbic system, cortex).
Reaction: radical behaviorism, no mind, just behavior.
B.F. Skinner, The Behavior of Organisms: An Experimental Analysis Of
Behavior (1938).
Brain => finite automata => behavior.
Gap between psychology and brain science, 1st and 3rd person view.
Mind the Gap
Gap between neuroscience and psychology: cognitive science is at best
incoherent mixture of various branches.
Is a satisfactory understanding of the mind possible ?
Roger Shepard, Toward a universal law of generalization for
psychological science (Science, Sept. 1987):
“What is required is not more data or more refined data but a different
conception of the problem”.
• Mind is what the brain does, a potentially conscious subset of brain
processes.
How to approximate the dynamics of the brain to get satisfactory
(geometric?) picture of the mind?
From molecules ...
10-10 m, molecular level: ion channels, synapses, membrane
properties, neurochemistry, biophysics, psychopharmacology,
mind from molecular perspective (Ira Black)?
10-6 m, single neurons: biophysics, computational neuroscience (CS),
compartmental models, spikes, LTP, LTD, neurochemistry &
neurophysiology.
10-4 m, small networks: neurodynamics, recurrence, spiking neurons,
synchronization, neural code (liquid?), memory effects,
multielectrode recordings, neurophysiology, CS.
10-3 m, neural assemblies: cortical columns, multielectrode & large
electrode recordings, microcircuits, neurodynamics,
neuroscience, CS.
… to behavior.
10-2 m, mesoscopic networks: self-organization, sensory and motor
maps, population coding, continuous activity models,
mean field theories, brain imaging, EEG, MEG, fMRI.
10-1 m, transcortical networks, large brain structures: simplified
models of cortex, limbic structures, subcortical nuclei,
integration of functions, concept formation, sensorimotor
integration, neuropsychology, computational psychiatry ...
And then a miracle happens …
1 m, CNS, brain level: intentional behavior, psychology,
thinking, reasoning, language, problem solving, symbolic
processing, goal oriented knowledge-based systems, AI.
Where is psyche, the inner perspective?
Lost in translation: networks => finite state automata => behavior
Alternative: Platonic model => mental events.
P-spaces
Psychological spaces:
K. Lewin, The conceptual representation and the measurement of
psychological forces (1938), cognitive dynamic movement in
phenomenological space.
George Kelly (1955), personal
construct psychology (PCP), geometry
of psychological spaces as alternative
to logic.
A complete theory of cognition, action,
learning and intention.
PCP network, society, journal, software
…
Many things in philosophy, dynamics,
neuroscience and psychology are
relevant here.
P-space definition
P-space: region in which we may place and classify
elements of our experience, constructed and evolving,
„a space without distance”, divided by dichotomies.
P-spaces should have (Shepard 1957-2001):
• minimal dimensionality;
• distances that monotonically decrease with
increasing similarity.
This may be achieved using multi-dimensional non-metric
scaling (MDS), reproducing similarity relations in lowdimensional spaces.
Can one describe the state of mind in similar way?
Minds work in low D!
Mind uses only those features that are useful to act/decide.
The structure of the world is internalized in the brain.
3 examples of elegant low-D mental principles in vision:
• In a 3-D vector space, in which each variation in natural
illumination is cancelled by application of its inverse from the
three-dimensional linear group of terrestrial transformations of
the invariant solar source, color constancy is achieved.
• Positions and motions of objects represented as points and
connecting geodesic paths in the 6-D manifold (3-D Euclidean
group of positions and 3-D rotation of each object) conserve
their shapes in the geometrically fullest and simplest way.
• Kinds of objects support optimal generalization/categorization
when represented as connected regions with shapes
determined by Bayesian revision of maximum-entropy priors.
From neurodynamics to P-spaces
Modeling input/output relations with some internal parameters.
Walter Freeman: model of olfaction in rabbits, 5 types of odors, 5
types of behavior, very complex model in between.
Simplified models: H. Liljeström.
Attractors of dynamics in high-dimensional space => via fuzzy symbolic
dynamics allow to define probability densities (PDF) in feature spaces.
Mind objects - created from fuzzy prototypes/exemplars.
Michael Gazzaniga
• M. Gazzaniga, The Ethical Brain 1998
The physical world is determined => brains must also be determined.
We human beings have a centric view of the world. We think our
personal selves are directing the show most of the time. I argue that
recent research shows this is not true but simply appears to be true
because of a special device in our left brain called the interpreter. This
one device creates the illusion that we are in charge of our actions.
Based on the modern understanding of neuroscience and on the
assumptions of legal concepts, I believe the following axioms: Brains
are automatic, rule-governed, determined devices, while people are
personally responsible agents, free to make their own decisions.
Personal responsibility is a public concept.
Those aspects of our personhood are – oddly – not in our brains. They
exist only in the relationships that exist when our automatic brains
interact with other automatic brains. They are in the ether.
Which self?
A. Damasio, The Feeling of What Happens: Body and Emotion in the
Making of Consciousness (1999) .
Elements of self at different levels:
• Proto-self: information about inner environment, mostly
from the brain stem and hypothalamus; allows for
homeostasis but is not directly conscious.
• Core self: awareness of here and now, giving the feeling of
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presence even in complete anterograde amnesia.
Autobiographical self, based on memory and anticipations.
Other divisions:
• Phenomenology: primary and reflective consciousness.
• N. Block: access-consciousness = representational, thoughts,
beliefs and desires, and phenomenal consciousness = experience.
Self-recognition
G.G. Gallup, Self-recognition in primates: A comparative approach to the
bidirectional properties of consciousness. American Psychologist 32:
329-38 (2002);
So far observed in chimps, orangutans,
gorillas, elephants and dolphins.
The concept of “I” entails understanding of
mental states of others, empathy.
Other test: if there are to people pointing to
food, but one with eyes covered, chips
usually follow the advice of the other one.
Understanding mental states of others helps to predict their behavior.
Possible role of mirror neurons, or multimodal neurons.
Is this the basis of self-awareness?
How to find self in the brain?
Kelley et al. JCN 14, 785-704, 2002; consider yourself, president Bush,
or case of letters used to write the word (neutral condition).
Where is the self in the brain?
Kelley et al. 2002, fMRI study
Where exactly is self?
C.L. Heatherton et al, Medial prefrontal activity differentiates self from
close others. Social Cognitive & Affective Neuroscience 1, 18-25, 2006.
Social judgements about others activate dorsomedial prefrontal cortex
(DMPFC) stronger than self-referential judgments (for which
VMPFC is more active)
and activate anterior
cingulate gyrus (AC).
Representation of self
in orbital and medial
prefrontal cortex
(OMPFC): continuous
representation of selfreferential stimuli.
„Self” in relation to
others = social self.
Various selves
Northoff et.al, Self-referential processing in our brain - a meta-analysis
of imaging studies on the self. Neuroimage 31, 440, 2006
CMS, Cortical Midline Structures, are all involved in the verbal, spatial,
emotional and face recognition test when self and others are
distinguished. These structures are rarely damaged and are in
between the rest of the cortex and limbic/brain stem structures.
Proto-self: body; autobiographical: memory; social: relations.
Who is acting?
Farrer & Frith, Experiencing Oneself vs Another Person as Being the
Cause of an Action: The Neural Correlates of the Experience of Agency,
Neuroimage 15, 596, 2002.
Awareness of intentional acting correlates with anterior insular cortex
(AIC), and passive acting when other person makes the movements with
activity of inferior parietal cortex (IPC).
AIC: may be concerned with the
integration of all the concordant
multimodal sensory signals
associated with voluntary
movements.
IPC: represents movements in an
allocentric coding system that can
be applied to the actions of others
as well as the self.
Empathy
Jackson et .al, How do we perceive the pain of others? (2005)
ACC plays a role in analysis and behavioral control connected with
avoidance of painful situations, combining attention and evaluation of
emotional value assigning silence to the even.
AIC receives information about pain monitoring physiological state of the
body; ACC & AIC react to the pain in self and others.
Intentions in the brain
Hayens et al, Current Biology 2007: you will see two numbers and you
may add or substruct them ... activity of the medial frontal cortex will
show what are your intentions even before you begin ...
Observer may know first ...
B. Libet et al. The Volitional Brain: Towards a
Neuroscience of Free Will (2000).
Classical experiments of Libeta: stimulation
of a finger is felt 500 ms before stimulation
of the cortex.
Observation of ERPs shows 300 ms
before the feeling “I want to press a
button” arises, first movement is
planned and then decision and
awareness of that decision follows.
Can we freely veto decisions?
Trevarna & Miller 2002, & others.
TMS stimulations: even if one side is
selected 80% of times the choice is felt
as free ... we could be radio controlled!
But we have qualia!
Why do qualia exist?
Imagine a rat smelling food.
In fraction of a second rat has to decide: eat or spit?
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Smell and taste a bit.
Request for comments is send to memory from the gustatory cortex.
Memory is distributed, all brain has to be searched for associations.
Request appears as a working memory (WM) pattern at the global
brain dynamics level.
WM is small, just a few patterns fit in (about 7 in humans).
Resonant states are formed activating relevant memory traces.
Answer appears: bad associations! probably poison! spit!
Strong physiological reaction starts – perception serves action.
The WM episodic state is stored for future reference in LTM.
Rat has different "feelings" for different tastes.
If the rat could comment on such episode, what would it say?
Results of this non-symbolic, continuous taste discrimination have to
be remembered and associated with some reactions: qualia!
More on qualia
Long Term Memory (LTM) is huge, stored by 100T synapses.
Working Memory (WM) is probably based on dynamical brain
states (actualization of LTM potential possibilities).
• Adaptive resonant states: the up-going (sensory=>conceptual) and
the down-going (conceptual=>sensory) streams of information
self-organize to form reverberations, transitory brain/mind states.
• Resonant states are “dressed”: they contain associations, memories,
motor or action components, in one dynamical flow – this is quite
different from abstract states of the Turing machine registers.
What happens to the taste of a large ice-cream?
The taste buds provide all the information; the brain processes
it, but the qualia are gone after a short time.
Why? WM is filled with other objects, no resonances with
gustatory cortex are formed, no reference to taste memories.
Brain-like computing
Brain states are physical, spatio-temporal states of neural tissue.
• I can see, hear and feel only my brain states!
• Cognitive processes operate on highly processed sensory data.
• Redness, sweetness, itching, pain ... are all physical states of brain
tissue.
In contrast to computer registers,
brain states are dynamical, and
thus contain in themselves many
associations, relations.
Inner world is real! Mind is based
on relations of brain’s states.
Computers and robots do not
have anything similar to the
dynamical working memory.
Why do we feel the way we do?
Qualia must exist in brain-like computing systems:
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Qualia depend on cognitive mechanisms; habituation,
intensive concentration or attention may remove qualia.
Qualia require correct interpretation, ex: segmentation of visual
stimuli from the background; no interpretation = no qualia.
Secondary sensory cortex is responsible for interpretation; lesions
will lead to change in qualia (asymbolia).
Visual qualia: clear separation between higher visual areas
(concepts, object recognition) and lower visual areas; activity of
lower only should lead to qualia (eg. freezing V4 - no color qualia).
Memory is involved in cognitive interpretation: qualia are altered by
drugs modifying memory access.
Cognitive training enhances all sensory qualia; memorization of
new sounds/tastes/visual objects changes our qualia.
How does it feel to do the shoe laces? Episodic memory (resonant
states) leads to qualia; procedural memory (maps) - no qualia.
Phenomenology of pain: no pain without cognitive interpretation.
Wrong interpretation of brain states – unilateral neglect, body
dysmorphia, phantom limbs controlled by visual stimulation mirrors.
Blindsight, synesthesia, absorption states ... many others.
Requirements for qualia
System capable of evaluation of their WM states, must claim to have
phenomenal experiences and be conscious of these experiences!
Minimal conditions for an artilect to claim qualia and be conscious:
• Working Memory (WM), a recurrent dynamic model of current global
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system (brain) state, containing enough information to re-instate the
dynamical states of all the subsystems.
Permanent memory for storing pointers that re-instate WM states.
Ability to discriminate between continuously changing states of WM;
"discrimination" implies association with different types of responses
or subsequent states.
Mechanism for activation of associations stored in
permanent memory and for updating WM states.
Act or report on the actual state of WM.
Representation of 'the self', categorizing the value of different states
from the point of view of the goals of the system, which are
implemented as drives, giving a general orientation to the system.
Conscious => subconscious
Learning: initially conscious involvement (large
brain areas active) in the end becomes automatic,
subconscious, intuitive (well-localized activity).
Formation of new resonant states - attractors in
brain dynamics during learning => neural models.
Reinforcement learning requires observing and evaluating how
successful are the actions that the brain has planned and is executing.
Relating current performance to memorized episodes of performance
requires evaluation + comparison (Gray – subiculum), followed by
emotional reactions that provide reinforcement via dopamine release,
facilitating rapid learning of specialized neural modules.
Working memory is essential to perform such complex task.
Errors are painfully conscious, and should be remembered.
Conscious experiences provide reinforcement; there is no transfer
from conscious to subconscious.
So, are we automata?
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The role of chaotic processes (Freeman) is still
controversial, but chaotic automata are still automata.
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Brain is a physical device, so „I” do not exist? No!
Brain is much more than „I”, and much more then just brain matter!
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Brain is just a substrate of mental processes. It contains the whole
evolutionary history (phylogenesis) as well as personal history.
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My brain made me do it! Brain are responsible for „our” decisions, „I”
interprets what the brain wants or experiences (ex. split brain,
lesions, neglect, “stronger then me” drives, learning about myself).
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Illusion that ‘I’ act is strong but we can deprogram ourselves, see
Susan Blackmore, what is left when self is gone? Not only the whole
brain but even bigger self, trough strong interaction with others and
the environment.
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We should be able to build brain-like systems; will they be automata?
Thank
you
for
lending
your
ears
...
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