Wednesday 23 April 2014

Integrated information theory - a theory of consciousness

A theory of consciousness.
I [Max Tegmark] have long contended that consciousness is the way information feels when processed in certain complex ways. The neuroscientist Giulio Tononi has made this idea more specific and useful, making the compelling argument that for an information processing system to be conscious, its information must be integrated into a unified whole. In other words, it must be impossible to decompose the system into nearly independent parts – otherwise these parts would feel like two separate conscious entities. Tononi and his collaborators have incorporated this idea into an elaborate mathematical formalism known as integrated information theory (IIT).

IIT has generated significant interest in the neuroscience community, because it offers answers to many intriguing questions. For example, why do some information processing systems in our brains appear to be unconscious? Based on extensive research correlating brain measurements with subjectively reported experience, neuroscientist Christof Koch and others have concluded that the cerebellum – a brain area whose roles include motor control – is not conscious, but is an unconscious information processor that helps other parts of the brain with certain computational tasks.

The IIT explanation for this is that the cerebellum is mainly a collection of "feed-forward" neural networks in which information flows like water down a river, and each neuron affects mostly those downstream. If there is no feedback, there is no integration and hence no consciousness. The same would apply to Google's recent feed-forward artificial neural network that processed millions of YouTube video frames to determine whether they contained cats. In contrast, the brain systems linked to consciousness are strongly integrated, with all parts able to affect one another.
The fourth state of matter: Consciousness - opinion - 09 April 2014 - New Scientist

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