What is consciousness ? I mean, what is the movie playing in your head everyday since you were aware of it after you were born? The movie not only deliver you the most real visual, audial excitation which you might have experienced when watching a 3D movie, but also gives you all physical sensation that feels like you are in a virtual reality simulator. What is the movie, aside from its multiple sensory stimulations and never-ending story, in which you experienced emotions, desires, and spirituality, and the only protagonist in the story is ‘you’ ?
Consciousness in the description above can be concisely summarized as ‘the collection of all subjective feelings induced by our experience.’ One may see it absurd and impractical to try to deal with subjective feelings in terms of physicalism because for hundreds of years the two main streams of etymology are idealism and physicalism, which are thought to be incompatible to each other. Despite the success of science, or its under-lied belief in physicalism, it has not provide yet a convincing explanation for the mechanism of our subjective experience. The term subjective explains itself: what happens in mind. How can we measure something that happened in our mind objectively after all?
However, the enormous success of scientific methods and its flourishing achievements make physicalism a universal belief. The most faithful believers of physicalism- scientist - have virtually become prophets of modern era. For any devotee to physicalism, who believes mechanical universe and dismiss super-nature phenomenon, what can be harder to accept than a truth that our minds are not part of this universe ?
Indeed, neuroscientists have discovered many valuable facts about our brains- how areas of brains correlate to difference mental processes- but they simply have no clue which area is in charge of our subjective feelings. Some scientists thus suggest our mental processes are not only a result from the teamwork of each functional brain areas, but also a quintessential ‘emergent phenomenon’ plays behind the scene.
Emergent phenomenon is basically a belief that cortical neural network is neither centralized nor localized as brain scientists observed on EEG or fMRI. Cortical neural network works as a decentralized, integrated whole where every ensemble of interactions of nodes and connections represents a specific mental state.
Then, how come this two seemingly contradictory views, either of which is supported by considerable evidences, can be fused into a unifying, self-rounded theory of brain ? Some scientists lay their hope in the complex system. Complex systems, which is neither centralized nor decentralized, exhibit hierarchical structures. The hierarchy is not built block by block on account of genetic blue map, but self-organized. The neural network is organized via its agents performing certain simple rules, instead of being dictated or supervised by an external higher being. The most famous rule of such is Hebbien Rule, usually described as ‘fire together, wire together.’
When I was organizing my thoughts about ‘what is consciousness ?’ It was clear to me that most of my inspirations should be credited to Jeff Hawkins and his philosophical but realistic booklet on Intelligence. His book delineate why intelligence is making prediction and how the cortical neuron might have achieved that. He proposed a group of simultaneously fired neuron may stand for one basic element of our world, and an ensemble of similar elements will be categorized into a superior concept, which will be represented by another group of neuron in a higher layer of neocortex. For example, our ears first receive a vibration of waves when we listen to a speech. The vibration is then transformed to an electric signal of sound, which to bottom layer of cortex may sounds like alphabet. When it adaptation to the certain combination of alphabets, which always occur consecutively, it recognizes the combination, the word, with a group of sync-fired neuron. Likewise, it recognizes patterns of combinations of words in to sentence in next layer. Finally, the meaning of the speech is captured through this hierarchical information processing system. Most tasks are well-learned patterns, are trivially predicted in lower layers of cortex, so it never cross our mind. Namely, only fresh, novel stimulation will finally enter the highest layer of neocortex, where our awareness functioned. Hawkins’s theory is fascinating because it consists with our experiences and easy to understand. It can be easily tested by simply recall you did not really think about the pronunciation of words when you are reading this article. Sometimes you did not even noticed misspellings or grammar error because you subconsciously predicted what the word means. However, we are aware of the spelling of words, and have difficulties understand sentences some times when we are listening to unfamiliar foreign languages. Allow me call the theory above ‘Intelligence theory.’
I think Jeff Hawkins has explained how intelligence works pretty clearly, given how ignorant we are to it previously. He also mentioned he has not figured everything out about consciousness, since it absolutely has something to do with cerebellum, thalamus, and hippocampus, etc. The picture of consciousness is incomplete without a complete understanding of emotions, animal instincts, and their interactions with intelligence. Jeff Hawkins just explained the new brain (neocortex ) , leaving the old brain undiscussed.
To understand subjective experience
No comments:
Post a Comment