There is no general answer to this question. Researchers don’t know exactly which parts of the brain contribute to consciousness in which situation. It also differs from person to person. Nevertheless, scientists can recognize activities in the brain and even convert some of them into control signals for computers.
The brain, together with the spinal cord, is the human control center. It controls and coordinates body activities and processes external stimuli – partly unconsciously, partly consciously. The human brain has over 100 billion nerve cells. Nerve cell activity is responsible for everything our brain does – every movement, perception, or thought. The interaction of these cells triggers every single action of the human body.
Can consciousness be detected in the human brain?
The transportation of electrically charged particles determines the activity of a nerve cell. Nerve cells process stimuli or initiate action. When thousands of cells in the brain become active at the same time an electrical current flows. This electrical current is very weak but measurable. Doctors can measure this current using electroencephalogram (EEG), and thus map the activity of individual areas of the brain.
There is also a link between the activity of nerve cells and blood flow to the respective brain areas. In short, more nerve cell activity in a specific region of the brain means more blood flow. It is possible to observe this association using functional magnetic resonance imaging (fMRI). This method creates three-dimensional images of the human brain and shows which areas are particularly active.
It is above all these two methods that give scientists an insight into the human consciousness. EEG and fMRI can also provide information about awareness, conscious perception, and action. Particular patterns of brain activity reflect recognizing an image, as well as planning and acting.
The cerebral cortex
Roughly it can be said that the cerebral cortex is central to consciousness. It is responsible for experiencing, thinking, feeling, action, color, and sound perception. But other parts of the brain also participate in conscious activities.
However, there is no exact assignment of thoughts, perceptions, or activities to a single, precisely defined area of the brain. While there are no “consciousness neurons” in the brain, every single thought has a distinctive activity pattern. This pattern differs from person to person. This difference is the reason every person associates something else with a particular perception. The activity pattern of the brain reflects these perceptions. For example, negative or positive attitude to dogs based on past experiences.
However, if you have identified the activity pattern of thought then you can reliably recognize it in the EEG. These abilities are already in use today. Not just an action, but the very thought of that action creates a particular pattern of brain activity. The brain-computer interfaces developers use this knowledge. With the help of an EEG, they read out a person’s brain activity. Thus converting specific patterns into a control signal. For example, to enable immobile people to operate computers or control prostheses.