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In-Depth Information
2 Psychophysiological Research on Mental Disorders:
Studies Using fMRI
2.1 Implementation of fMRI Studies
As described in the previous section, a plethora of assessment methods can be used
in psychophysiological research on mental disorders. In this section, we will discuss
studies that used fMRI.
fMRI assessments can be performed with a 1.5 Tesla MRI scanner widely used
in standard clinical practice. fMRI capabilities are also commonly available in
research institutions, such as the ATR Brain Activity Imaging Center (
http://www.
baic.jp/
). Participants in MRI experiments perform cognitive tasks inside an MRI
scanner, during which time images of the brain are taken. This method requires the
placement of various devices inside the MRI scanner, such as monitors, speakers,
and response buttons. Presentation (Neurobehavioral Systems, Inc.) is frequently
used as a task creation and presentation software application in fMRI studies. In
addition, BOLD signal changes associated with neural activity in the brain during
task performance typically produces a small percentage in signal and a small signal-
to-noise ratio (S/N ratio). Therefore, numerous repetitions of task trials and asso-
ciated functional brain imaging must be conducted, and both of the above require
ac.uk/spm
) is frequently used as an image processing and statistical analysis soft-
ware application in fMRI studies. Please refer to [
8
] for more details regarding
fMRI assessment and analysis.
At the Hiroshima University Department of Neuropsychiatry (to which we, the
authors, belong), we are conducting basic studies with healthy individuals and
studies on patients with mental disorders using fMRI in order to elucidate the
pathologies of various mental disorders. We will now review some of these studies.
2.2 Alexithymia
Alexithymia is a condition with psychobehavioral characteristics such as dimin-
ished imaginative capacity and dif
!
culty in recognizing and expressing one's own
emotions. Alexithymia is observed in various mental disorders, such as somatoform
disorders, anxiety disorders, and substance dependence. Mantani et al. [
9
] con-
ducted a study for examining brain functions related to emotional impairment and
imaginative impairment in alexithymia. Young healthy subjects were divided into a
high degree of alexithymia group (N = 10) and a low degree of alexithymia group
(N = 10) based on their scores on the 20-item Toronto Alexithymia Scale (TAS-20).
fMRI was used to assess subjects' brain activation as they imagined past and future
happy, sad, and neutral events.
