Presentation on theme: "Are we automata? Włodzisław Duch Department of Informatics Nicolaus Copernicus University, Toruń, PL Google: W. Duch Google: W. Duch Self, intersubjectivity."— Presentation transcript:
Are we automata? Włodzisław Duch Department of Informatics Nicolaus Copernicus University, Toruń, PL Google: W. Duch 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.
NeurologistsNeurologists 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)Does 'Consciousness' Exist 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.
AutomatismsAutomatisms 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, 1 st and 3 rd 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 -3 m, neural assemblies: cortical columns, multielectrode & large electrode recordings, microcircuits, neurodynamics, neuroscience, CS. 10 -4 m, small networks: neurodynamics, recurrence, spiking neurons, synchronization, neural code (liquid?), memory effects, multielectrode recordings, neurophysiology, CS.
… to behavior. … 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-spacesP-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 low- dimensional 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 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 self- referential 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.
EmpathyEmpathy 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). 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! Classical experiments of Libeta: stimulation of a finger is felt 500 ms before stimulation of the cortex.
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? 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: 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 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? The role of chaotic processes (Freeman) is still controversial, but chaotic automata are still automata. Brain is a physical device, so „I” do not exist? No! Brain is much more than „I”, and much more then just brain matter! Brain is just a substrate of mental processes. It contains the whole evolutionary history (phylogenesis) as well as personal history. 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). 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. Susan Blackmore We should be able to build brain-like systems; will they be automata?
Thank you for lending your ears... Google: W. Duch => Papers, Talks