What is brain imaging?
Neuroimaging or brain imaging is the use of various techniques to either directly or indirectly image the structure, function, and pharmacology of the nervous system. It is a relatively new discipline within medicine, neuroscience, and psychology. Brain imaging has given scientists and researchers unprecedented insight into the inner function of the brain and the rapidly developing ability to correlate brain activation with psychological states and traits.
One of the most widely discussed new applications of imaging is based on correlations between brain activity and intentional deception. Intentional deception can be thought of in the context of a lie detector. This means that scientists use brain imaging to look at certain parts of the brain during moments when a person is being deceptive. A number of different research groups have identified fMRI correlates of intentional deception in laboratory tasks, and despite the skepticism of many experts, the technique has already been commercialized. A more feasible application of brain imaging is “neuromarketing“, whereby people’s conscious or unconscious reaction to certain products can purportedly be measured.
Researchers are also finding brain imaging correlates of myriad psychological traits, including personality, intelligence, mental health vulnerabilities, attitudes toward particular ethnic groups, and predilection for violent crime. Unconscious racial attitudes may be manifest in brain activation. These capabilities of brain imaging, actual and potential, raise a number of ethical issues. The most obvious concern involves privacy. For example, employers, marketers, and the government all have a strong interest in knowing the abilities, personality, truthfulness and other mental contents of certain people. This raises the question of whether, when, and how to ensure the privacy of our own minds.
Another ethical problem is that brain scans are often viewed as more accurate and objective than in fact they are. Many layers of signal processing, statistical analysis, and interpretation separate imaged brain activity from the psychological traits and states inferred from it. There is a danger that the public (including judges and juries, employers, insurers, etc.) will ignore these complexities and treat brain images as a kind of indisputable truth.
A related misconception is called neuro-realism: In its simplest form, this line of thought says that something is real because it can be measured with electronic equipment. A person who claims to have pain, or low libido, or unpleasant emotions is “really” sick if these symptoms are supported by a brain scan, and healthy or normal if correlates cannot be found in a brain scan. The phenomenon of phantom limbs demonstrates the inadequacy of this approach.