From neurons to brain - Eric Kandel

As far as we kown, no complex human behavior is initiated by a single neuron ... each behavior is generated by the action of many cells.
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What makes the brain a remarkable information processing machine is not the complexity of its neurons, but rather its many elements and, in particular, the complexity of connections between them.
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Specific types of information are processed in particular regions ... information from each of our senses is mapped to distinct brain regions ... These maps are the first stage in creating a representations of the outside world in our brain.
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Connections between motor, sensory and interneuronal maps are established as the brain develops and determine the behavior of individual cells.
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The logical operations of a mental representation can be understood only by defining the flow of information through connections between maps.
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What makes the brain a remarkable information processing machine is not the complexity of its neurons, but rather its many elements and, in particular, the complexity of connections between them.

Principles of Neural Science, p. 33-34