Trong khi quá trình động học thông tin liên lạc thần kinh cho thấy rằng hành động não trông rất giống như một hành động máy tính, có một số khác biệt cơ bản phải làm với một tài sản cơ bản não gọi là não dẻo. Mối liên kết giữa các tế bào thần kinh không cố định | 17 While the dynamical process of neural communication suggests that the brain action looks a lot like a computer action there are some fundamental differences having to do with a basic brain property called brain plasticity. The interconnections between neurons are not fixed as is the case in a computer-like model but are changing all the time. Here I am referring to the synaptic junctions where the communication between different neurons actually takes place. The synaptic junctions occur at places where there are dendritic spines of suitable form such that contact with the synaptic knobs can be made. Under certain conditions these dendritic spines can shrink away and break contact or they can grow and make new contact thus determining the efficacy of the synaptic junction. Actually it seems that it is through these dendritic spine changes in synaptic connections that long-term memories are laid down by providing the means of storing the necessary information. A supporting indication of such a conjecture is the fact that such dendritic spine changes occur within seconds which is also how long it takes for permanent memories to be laid down 12 . Furthermore a very useful set of phenomenological rules has been put forward by Hebb 26 the Hebb rules concerning the underlying mechanism of brain plasticity. According to Hebb a synapse between neuron 1 and neuron 2 would be strengthened whenever the firing of neuron 1 is followed by the firing of neuron 2 and weakened whenever it is not. A rather suggestive mechanism that sets the ground for the emergence of some form of learning It seems that brain plasticity is not just an incidental complication it is a fundamental property of the activity of the brain. Brain plasticity and its time duration few seconds play a critical role as we will see later in the present unified approach to the brain and the mind. Many mathematical models have been proposed to try to simulate learning based upon the close resemblance of the .
