1 / 22

Consciousness

Consciousness. Francis Crick. The Astonishing Hypothesis The Scientific Search for the Soul.

odessag
Download Presentation

Consciousness

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Consciousness

  2. Francis Crick TheAstonishing Hypothesis The Scientific Searchfor the Soul

  3. “The Astonishing Hypothesis is that ‘you’, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules. As Lewis Carroll’s Alice might have phrased it, “You’re nothing but a pack of neurons”. F. Crick The Astonishing Hypothesis

  4. “consciousness. The having of perceptions, thoughts, and feelings; awareness. The term is impossible to define except in terms that are unintelligible without a grasp of what consciousness means. Many fall into the trap of equating consciousness with self-consciousness – to be conscious it is only necessary to be aware of the external world. Consciousness is a fascinating but elusive phenomenon; it is impossible to specify what it is, what it does, or why it evolved. Nothing worth reading has been written on it.” – Stuart Sutherland, The International Dictionary of Psychology

  5. “As recently as a few years ago, if one raised the subject of consciousness in cognitive science discussions, it was generally regarded as a form of bad taste, and graduate students, who are always attuned to the social mores of their disciplines, would roll their eyes at the ceiling and assume expressions of mild disgust.” – John Searle

  6. A Universe of ConsciousnessHow Matter Becomes Imagination Gerald M. Edelman And Giulio Tononi

  7. How Matter Becomes Consciousness When I turn my gaze to the sky, I SEE the heavenly dome of the sky and the sun’s brilliant disc and hundreds of other visible things all around. I see; I experience. What are the steps that bring this about? A beam of light enters the eye and is focused on the retina; it gives rise to change that connects to a layer at the top of the brain. The whole chain is physical; each step is an electrical interaction. Suddenly a visual scene presents itself to the mind. I SEE the sky and the sun and all the other things around. I perceive a picture of the world. How does this last step show up?

  8. DESCARTES! We are at the footsteps where Consciousness can be considered as a scientific subject and not the sole province of the philosopher. • René Descartes: “Cogito ergo sum”, “I THINK THEREFORE I AM”. “I am conscious, therefore I exist”. This leads to solipsism “nothing exists without consciousness”. • Today science is saying “I AM THEREFORE I THINK”. There is no ‘conscious’ substance separate from a ‘brain’ substance. Consciousness is not an object but a process and a fitting scientific subject. It is a process of integration and selection through differentiation in terms of neural interactions.

  9. Conscious or Not • Why multiplication performed by a human is a slow conscious process while the same multiplication quickly carried out by a pocket calculator is presumably not conscious at all? • Why is it that when we perform a discrimination such as between light and dark, each of us is conscious, but a similar discrimination performed by a simple physical device is apparently not associated with conscious experience? • Why is it that we are conscious of hot or cold, but we are not directly conscious of whether our blood pressure is high or low? After all there are neural circuits for both. Why do certain neural circuits make us be ‘aware’ and others not? • Why is it that when we lose a chess game to a computer we are conscious, but the computer is not? • What is special about consciousness?

  10. Neural Basis of Consciousness Neural basis of Consciousness, with properties of unity or integration, with differentiation or informativeness. UNITY: related to our inability to do two complex things at the same time (balance a checkbook and read a book). The occurrence of a certain conscious state precludes the simultaneous occurrence of another one. When I see the number 17, I think of 17, not of a 1 and a 7. This is related to the brain’s ‘capacity limitations’. We cannot keep in mind more than a few things at a time. We can see a string of numbers, but we can report only a few from memory. DIFFERENTIATION: We can select one of billions of conscious states in a fraction of a second. To a human being, darkness and light experience are two special conscious experiences out of an enormous repertoire, and their selection implies a correspondingly large number of discrimination steps to arrive at one or the other. Consciousness is inexorably linked to certain parts of memory. Immediate memory is associate with consciousness.

  11. The Brain The adult human brain weighs ~3 pounds and contains ~100 billion nerve cells, or neurons. The brain is among the most complicated objects in the universe and the most remarkable structure that has emerged during evolution. Conscious experience seems to be associated with neural activity that is distributed simultaneously across neural groups in different parts of the brain. These must interact rapidly and reciprocally – called ‘reentry’. For consciousness to appear neural groups must be able to select among a large number of differentiated activity patterns. • PLATO through that ‘consciousness’ was connected with the BRAIN. ARISTOTLE thought ‘consciousness’ was connected with the HEART. • The brain is not a ‘computer’: The billions and billions of connections in the brain are not exact. Nor two brains are exactly identical, but the overall pattern is the same. Nevertheless, each brain is unique. This allows us ‘individualism’ and ‘freedom’. • ‘EACH’ evolves and changes unlike a ‘SINGLE’computer. It appears that Darwinian principles of variation and natural selection are sufficient to explain the function of the brain and elements of spiritualism are not required for our being conscious.

  12. Levels of Consciousness • Primary Consciousness: The ability to generate a mental scene and generate immediate behavior. Animals have PC. • Higher Order Consciousness: Made up of PC with the ability to connect past and future scenes. Requires semantic capability and linguistic capability. Being conscious that you are conscious! Consciousness and complexity are intimately linked, and information deals with neural complexity. There are billions of conscious states in a brain. The ability to differentiate among new states constitutes information, which is the reduction of uncertainty among a number of alternatives. This is how the brain decides. Memory is a central component of the brain mechanism that leads to consciousness. Memory results from the selective matching that occurs between ongoing, distributed neural activity and various signals coming from the world, the body, and the brain itself.

  13. Conscious Experience • Consciousness is not a thing or an object – it is a process. • Consciousness is a process of integration and unity. • Consciousness is private. Every conscious scene is not only unified but is experienced from a single point of view – since each brain is slightly different. • There is coherence of a conscious state. A person cannot be aware of two mutually incoherent scenes at the same time. • Consciousness is a Differential Process. This is how decisions are arrived at. • There is Flexibility and Ability to Respond and Learn from adaptive values of consciousness. • Consciousness has a limited capacity (e.g., to remember numbers in a row, etc.) • Consciousness is a Serial experience, that is one conscious state is followed by another. • Consciousness is a dynamic process constantly changing with every new experience.

  14. The Self Primary Consciousness can have scenes. These can be tied together through thought and language, which give new imagery. A discriminable and namable self develops through social interactions. Eventually, such a development permits a person to be conscious of being conscious. Neural changes that lead to language are behind the emergence of high-order consciousness. A self can be constructed from social relationships. The emergence of a self connects feelings to thoughts, to culture and to beliefs. Language is acquired through interpersonal interactions that are social, when enough language is in place the ‘self’ appears, capable of past and future scenes.

  15. Thinking • What goes on in your head when you have a thought? • We still do not know exactly. • The NEURAL basis of consciousness suggests that an awful lot goes on in your brain every time you have a thought. A good deal is information exchange having a complexity that is far beyond the capacity of any present day computer. • What keeps a thought going? • An intricate combination of ongoing perception, attention, memory, habit, and reward including previous learning and experience. • How are humans free in their thoughts? • Each brain is formed in a way that its wiring is dynamic and variable. It is a selectional system and each brain therefore is unique. • The brain generates an extraordinary amount of information in less than a second. Information acquires the potential of ‘subjectivity’, that is a free thought. “While we remain prisoners of description, the freedom is in the grammar”.

  16. The Brain is wider than the Sky – For – put them side by side – The one the other will contain With ease – and you – beside. Emily Dickinson

  17. “And still they gazed and still the wonder grew, That one small head could carry all he knew.” Oliver Goldsmith The Deserted Village

More Related