Brain mapping is a set of neuroscience techniques that aim to map biological features of the brains of humans and other animals to spatial representations. In other words, it is the study of the anatomy and function of the brain and spinal cord with the help of imaging techniques, immunohistochemistry, molecular and optogenetics, cell biology, engineering, neurophysiology and nanotechnology.
Brain Mapping Techniques
All imaging modalities can be considered some form of brain mapping. Higher-level mapping can be done by adding additional information about various brain functions onto the images. For example, magnetic resonance imaging (MRI) shows the anatomical shape. Functional MRI, on the other hand, can add information on how metabolically active certain regions are. In the special map method called a connectogram, all cerebral cortex areas are represented on a circle, and the connections between them are indicated by lines of varying thickness.
The European Union launched the “Human Brain Project” in 2013 to support brain research. Again in 2013, the “Brain Initiative” was launched in the USA. If brain structure and function are better understood, more effective treatments can be found for problems such as traumatic brain injury, stroke, and Alzheimer’s disease.
In the nineteenth century, scientists dealing with neuroscience began to map hitherto unknown areas of the brain, almost like explorers. However, due to the limited means at hand at the time, some hypotheses were put forward that we now know to be false. One of them was phrenology. Franz Gall, the founder of phrenology, suggested that different parts of the brain cause protrusions in the skull, and therefore, inferences can be made about the mental capacity and character of the person’s skull characteristics. Although this view proved untrue, the underlying problem remained significant: memory, attention, language, Do cognitive functions such as emotion and perception occur in specific areas of the brain or are they distributed throughout the brain? The way to test this is to damage a specific area of the brain with animal experiments and observe the results, or to analyze people with damage to certain parts of their brain.
An important step for brain mapping was Paul Pierre Broca’s discovery of the speech center in the brain in the 19th century. This area is still named after Broca. At the beginning of the 20th century, the German anatomist Korbinian Brodmann divided the brain into areas according to their histological features and numbered them (Brodmann areas).
Are the Functions Localized or Common?
Brain mapping evidence supports localization of functions. That is, there are specific areas in the brain for certain tasks. However, in order to perform an intended action in the real world, many different functions must be used together. For example, different skills such as muscle control for walking, interpretation of senses, balance and coordination, and decision making should work in harmony. It can be said that cognitive functions are neither fully localized nor evenly distributed in the brain. Each function requires a complex but specific network involving different brain areas .
The question to be asked is not where the cognitive functions are located spatially in the brain, but what are the mechanisms and interacting networks that enable these functions to emerge. Although there are parts of the brain that are specialized for certain functions, they do not work alone, but rather act as the hub of complex interactive networks. For example, the sense of fear is dependent on the amygdala. A person whose amygdala is removed becomes fearless. But what really makes you feel fear is the connections the amygdala makes with other parts of the brain.