This study will use magnetic resonance imaging (MRI) to identify brain regions involved in
performing certain tasks, especially those involving emotions. MRI is a diagnostic tool
that uses a strong magnetic field and radio waves to produce images of structural and
chemical changes in the brain. The study will also examine which MRI techniques are best to
use when scanning brain areas involved in different emotions.
Healthy normal volunteers between 18 and 40 years of age who are right-handed and are native
English speakers may be eligible for this study. Individuals with a history of neurological
disease, post-traumatic stress disorder or other psychiatric disorder, or who have a history
of physical or sexual abuse may not participate. Candidates will be screened with a written
questionnaire and a medical history, including psychiatric and neurological information.
Participants will perform tasks involving emotions while undergoing MRI scanning. For this
procedure, the subject lies on a table in a narrow metal cylinder (the scanner) containing a
magnetic field. Scanning time varies from 20 minutes to 3 hours, with most scans lasting
between 45 and 90 minutes. The subject is asked to lie still for up to 10 minutes at a
time. During the scan, the subject performs simple tasks involving the viewing of pictures
on a screen. Other tasks involve viewing pictures and responding to them by pressing
buttons. Some pictures are violent or pornographic, while others are pleasant to view. Of
a total of 162 pictures, 30 percent are categorized as graphic and possibly disturbing.
The purpose of the protocol is to localize the neural regions and systems mediating the
forms of knowledge representations hypothesized by the principal investigator to be stored
in the human prefrontal cortex. Utilizing experimental neuropsychological tasks during
functional MRI on healthy adult volunteers, we will investigate hypotheses regarding the
role of the ventromedial prefrontal cortex in social cognition and emotional processing as
opposed to the dorsolateral prefrontal cortex, involved in nonsocial-events (planning,
problem solving, economic exchange and reasoning). We will also attempt to determine the
relationship between non-frontal neural structures involved in emotional expression, such as
the amygdala, and those frontal neural structures involved in executive functions that may
modulate emotion. Another goal of our study is to test different fMRI sequences to
determine which one gives us the best quality of signal in the amygdala and orbitofrontal
cortex (affected by signal drop-out due to magnetic susceptibility artifacts). The data
that we collect in this protocol will be of value in (1) identifying a set of neural regions
and distributed networks mediating the forms of knowledge representation stored in the
prefrontal cortex, and (2) contributing to optimization of functional imaging of the
amygdala and orbitofrontal cortex at high field strength (3 Tesla). We will also use the
data obtained in these studies to constrain theories of frontal lobe function and to provide
evidence for the role of specific frontal cortex sectors in specific cognitive functions.
The study population will consist of young healthy volunteers.
Age range: 18 to 40
Right-handedness (some left-handed subjects may be recruited for preliminary behavioral
Individuals with a neurological or psychiatric history or medical condition that would
compromise our interpretation of the fMRI results will be excluded.
Individuals with a current or past history of post-traumatic stress disorder or other
psychiatric disorder or individuals with a history of physical or sexual abuse will be
excluded as they may be disturbed by viewing graphic pictures.
Subjects with contraindications to exposure to high magnetic field.