"The Story of the Brain" is a popular science book written by American neuroscientist David Eagleman. Since it is aimed at general readers, it does not contain much in-depth scientific analysis, but rather introduces some concepts. A relatively new concept for me is that empathy is actually to better understand the feelings of others; when we see others' expressions, our facial muscles mimic those expressions, and the corresponding nervous system experiences similar feelings. This also explains why people who have lived together for a long time tend to become similar.
To avoid excessive empathy, humans have adopted a categorization method, easily empathizing with those within their own circle while reducing empathy for those outside it. This also explains the need to dehumanize or vilify the opponent in wars, making it easier to take lethal action. It also explains why racial discrimination and clique culture are difficult to avoid.
The book introduces various senses that can actually substitute for each other, such as using touch to replace vision or hearing. Through special vests, camera information can be transmitted to the optic nerve, and after a period of time, the brain can learn to understand what video information is being conveyed. Similarly, this information can also be sent to the auditory nerve. Such devices can help blind or deaf individuals regain sight and hearing. This actually indicates that our sensory organs can be replaced, and in the future, it is entirely possible to enhance vision and hearing through advanced cameras or audio devices. Furthermore, by using brain-machine interfaces to directly transmit large amounts of information to the brain, it is possible that the brain could acquire so-called "artificial intelligence" faster than current supercomputers.
In addition to the possibility of sensory substitution, human memory can also be modified. Due to the abundance of memories, the brain generally only retains the most recent ones. By repeatedly instilling new false memories, most people can be made to remember only these new memories, forgetting their previous real memories, which is the basis for successful brainwashing.
The book also depicts a more distant idea of copying all the neurons and connections of the brain and uploading them to the network. Due to the complexity of the brain, the amount of information required for copying exceeds what humans can currently process. Moreover, since the brain is dynamically changing and may exhibit quantum behavior, it cannot be predicted or replicated. Therefore, the theoretical and technical challenges of uploading the human brain to achieve immortality remain significant, and can only be imagined in science fiction novels.
What makes each person unique is their own brain, which is composed of neural connections formed by long-term perception. The decisions people make are based on their perceptions of the outside world and the memories they have formed, collectively shaped by a large number of neurons, making each of your decisions a unique part of you.