Brain imaging

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.

Brain interventions

Neuroimaging in red

“New findings in neuroscience have given us unprecedented knowledge about the workings of the brain. Innovative research—much of it based on neuroimaging results—suggests not only treatments for neural disorders but also the possibility of increasingly precise and effective ways to predict, modify, and control behavior.” – Robert H. Blank, Intervention in the Brain

Brain interventions

The ethics of neurocognitive enhancement, that is the use of drugs and other brain interventions to make normal people “better than well”, is an example of a neuroethical issue with both familiar and novel aspects. On the one hand, we can be informed by previous bioethical work on physical enhancements such as doping for strength in sports and the use of human growth hormone for normal boys of short stature. On the other hand, there are also some arguably novel ethical issues that arise in connection with brain enhancement, because these enhancements affect how people think and feel, thus raising the relatively new issues of “cognitive liberty”. The growing role of psychopharmacology in everyday life raises a number of ethical issues, for example, the influence of drug marketing on our conceptions of mental health and normalcy, and the increasingly malleable sense of personal identity that results from what Peter D. Kramer called “cosmetic psychopharmacology”.

Nonpharmacologic methods of altering brain function are currently enjoying a period of rapid development, with a resurgence of psychosurgery for the treatment of medication-refractory mental illnesses and promising new therapies for neurological and psychiatric illnesses based on deep brain stimulation as well as relatively noninvasive transcranial stimulation methods. Research on brain-machine interfaces is primarily in a preclinical phase but promises to enable thought-based control of computers and robots by paralyzed patients. As the tragic history of frontal lobotomy reminds us, permanent alteration of the brain cannot be undertaken lightly. Although nonpharmacologic brain interventions are exclusively aimed at therapeutic goals, the US military sponsors research in this general area that is presumably aimed at enhancing the capabilities of soldiers.