Imaging the Brain — Finding Emotion
Fellow in the History of Biomedical Sciences and Technology
National Institute of Biomedical Imaging and Bioengineering
National Institutes of Health
About the Lecture
During the past twenty years the understanding of emotion shifted in the scientific literature from “emotional disorders” to emotion as “function of the brain.” How did this change from disorder to brain “function” came about? Extensive studies on the amygdala that began in the early 1980s were one important step. The development and increasing sophistication of imaging techniques and their application to the study of the brain was another one. In this talk I want to highlight how the development of Positron Emission Tomography, and of functional Magnetic Resonance Imaging changed the picture of emotion and cognition, and brought about the “turn to emotion” in the public sphere that we witnessed at the turn of the twenty-first century.
About the Speaker
CLAUDIA WASSMANN works in the National Institute of Biomedical Imaging and Bioengineering, where she is the Dewitt Stetten, Jr., Memorial Fellow in the History of Biomedical Sciences and Technology. She trained as a physician, receiving her M.D. summa cum laude from the University of Düsseldorf, but has devoted her professional life to science and medical journalism. She is an editor and producer with the science unit of German public television, Süddeutscher Rundfunk, in Heidelberg. Several of her programs have won major awards, most recently a 45-minute documentary called “Schizophrenia: The Biology of Madness.” Wassmann also writes medical articles for German newspapers and magazines. During her medical training, she worked at the University of Bologna Medical Clinic in pediatric surgery and at Djougou Hospital in Benin. Outside interests include reading, movies, travel, photography and the fine arts.
President William Saalbach called the 2,201st meeting to order at 8:16 pm February 10, 2006. The minutes of the 2,100th meeting were read and, more or less, approved. Some changes were made.
Mr. Saalbach then introduced the speaker of the evening, Ms. Claudia Wassman of the National Institute for Biomedical Imaging and Bioengineering and the Office of NIH History. Ms. Wassman spoke on “Imaging the Brain – Finding Emotion.” Ms. Wassman's objectives were to put imaging studies in historical perspective and highlight the impact of brain imaging on understanding of cognition and emotion.
Back in the 1950's, war neuroses were a major concern of people interested in brain function. In those days, emotions were viewed negatively. People were spoken of as “handicapped by mental and emotional disorders” that led to “anti-social behavior.”
In 1954, mental illness was reported by NIH to “[cost] the nation well over a billion dollars a year.” Mental and emotional disorders accounted for half the hospital beds in use. Emotional problems were said to be “responsible for much self-destructive or anti-social behavior, such as alcoholism, suicide, homicide, delinquency, and drug addiction.”
There were attempts to study the problem using animals. Ms. Wassman described one study based on a theory that the presence of a “good” sheep mother during prolonged stress would prevent the sheep from becoming neurotic.
The “talking cure,” psychotherapy, remained popular in the 1960's. In the 1980's interest in the physiology of mental problems grew with the support of doctors at NIH. They conducted the first brain imaging studies in the 1980's with schizophrenia patients.
As early as 1889, there had been attempts to measure cerebral blood flow. Ms. Wassman showed a picture of a subject lying on a table which was actually a tare scale. The pointer was supposed to swing and indicate when blood flowed to the subject's head. She did not say how successful that was.
Ms. Wassman traced the course of the development of methods of studying brains without removing them. Signal achievements were:
determination of cerebral blood flow, 1945, Seymour Kety and Carl Schmidt. They used nitrous oxide as a tracer.
the deoxyglucose method that eventually made PET (Positron Emission Tomography) scans possible. Louis Sokolov actually started working on this in the 1950's. He shelved the project several times. In 1977, he produced some radiographs of rat brains, but they required the brains to be frozen. In 1979, the method evolved to produce pictures of living human brains with the help of David Kuhl, the inventor of SPECT (Single Photon Emission Computed Tomography). PET scans have low resolution, but they have turned out to be useful for studying cancer, since most cancers are “hot,” meaning they are metabolically active.
Joseph LeDoux, attempting to refine Sokolov's autoradiography method, discovered that it was possible to detect specific changes in brain activity in reaction to a brief environmental stimulus. In a 1983 study he noted that presentation of auditory stimuli increased blood flow in the auditory but not the visual pathway.
In 1994, Antonio Damasio, at the University of Iowa, produced a bestseller called Descartes' Error. He argued that emotions were necessary for rational thought. Patients who lack emotions lack the emotional values that guide thought.
A 1994 study by Marcus Raichle found that depressed patients scored lower on perception of emotion in facial expression. Depressed patients did perceive affect in verbal descriptions of the face as well as normal subjects.
In the 1990's, NIMH got behind fNMI (functional Nuclear Magnetic Imaging). Use of fNMI to study emotions grew. NIMH now has its own fNMI facility. FNMI has much better resolution than PET, 1 mm to 4 mm, and measures in .1 second while PET needs 40 seconds.
In 1994, Richard Davison, University of Wisconsin - Madison, found activity in the amygdala correlated with affectively negative and affectively neutral pictures. Since then, researchers have worked to trace out more specific correlates between mood and brain activity. Davison also said that a higher baseline activity in the right prefrontal cortex makes people depression prone while higher baseline activity in the left prefrontal cortex predicts their resilience.
The importance of these imaging techniques is great. Before these techniques, studies of lesions in the brain were the only way to connect emotion with brain function. Brain observation has made a great leap forward with these scanning techniques and the data analyses that make them clearly visible.
The development of fMRI, which produces brain scans rapidly and precisely and without radiation, is especially important. It is now the method of choice for most purposes, although PET scans are still used for certain purposes such as studying binding of molecules. FMRI development earned Paul Lauterbur and Peter Mansfield the Nobel Prize in Physiology or Medicine in 2003. Ms. Wassman appeared to be very proud of the MRI center at NIMH. The technique has reached the point that Ms. Wassman was able to show us movies of human brains functioning. They have discovered such things as that damage to the amygdala impairs recognition of emotional facial expressions, which illustrates how specific new findings are. Old-fashioned lesion studies were involved in that development and now activity in specific areas of the amygdala have been found to correspond with recognition of certain emotions.
In a very recent study, Stephan Hamann discovered that individuals with short alleles are hyper-sensitive to negative stimuli and may, he speculates, be at increased risk of developing depression.
Ms. Wassman concluded that brain imaging studies have:
changed the concepts of emotion and cognition,
showed that the adult brain is changeable,
generated new fields of scientific inquiry, and
provided new tools for imaging genomics.
In the question period, someone asked why they don't study higher-order emotions. Ms. Wassman replied that anger and fear are the strongest emotions, by which I guess she meant the ones that stimulate the clearest responses in the brain.
Another person quoted an opinion that shame is the master emotion. Ms. Wassman said it is a higher-order emotion. “You wouldn't start with that,” she said.
After the talk, Mr. Saalbach presented Ms. Wassman a plaque commemorating the event. He encouraged people to consider joining the Society. He made the parking announcement. Finally, at 9:36 pm, he adjourned the 2,201st meeting to the social hour.
The weather: Hazy and misty
The temperature: 1°C
Ronald O. Hietala,