A Psychophysiological Approach Towards Understanding Emotions - Emotional Engineering - page 106

to other measurement methods, thus making it possible to grasp detailed position
information regarding brain activity. In addition, fMRI can produce excellent
analysis in terms of temporal resolution when applying event-related design. NIRS
is minimally restrictive and can record measurements even when there is some
movement; therefore, it can be applied in examinations of brain function for infants
and developmentally disabled children.
We have further outlined physiological indicators used in psychophysiology,
particularly indicators and methods for measuring CNS activity, which is a direct
indicator of brain activity. For details, please refer to [ 3 ].
1.3 The Role of Psychophysiology in Psychiatry
In psychiatry, a psychophysiological approach to research is considered to have the
potential of contributing signi ! cantly to bettering our understanding of mental
disorders associated with emotional, cognitive, and behavioral impairments. Major
contributions for the improvement of diagnostic and therapeutic techniques are also
anticipated.
Currently, studies are being conducted which examine mental disorders related
to emotion (e.g., anxiety disorders and mood disorders) from psychological per-
spectives (e.g., clinical psychology) and medical perspectives (e.g., psychophar-
macology); however, the pathologies of such disorders remains poorly understood.
In order to obtain a deeper understanding of the pathological basis of these dis-
orders, it is necessary to determine the relationship between psychological/behav-
ioral symptoms and the underlying neural mechanisms responsible for them. As
previously argued, psychophysiology is the discipline best suited to associate
psychobehavioral variables and physiological variables. Psychophysiology has a
large and growing role to play in the current research environment, as powerful
methods for assessing brain function are now highly developed.
It is important to keep in mind, the need to focus on and examine the patient's
psychological and behavioral condition from a psychology-based perspective rather
than a brain-based perspective. As an example, let us consider functional neuro-
imaging research in depression. Studies on resting brain glucose metabolism and
CBF in patients with depression have reported hypofrontality with relative con-
sistency [ 4 ] . In particular, many studies have demonstrated hypofrontality in the
dorsolateral prefrontal cortex and hypofunctioning in the anterior cingulate cortex
[ 5 ]. There have also been attempts to investigate brain activation during cognitive
task performance in patients with depression. Hypofrontality is observed at rest in
these patients.
Therefore, in order to conduct a detailed examination of prefrontal cortex
activity, changes in brain activation during task performance are investigated using
prefrontal functional tests adopted from conventional clinical settings. A PET study
using the Tower of London task reported that patients with depression demonstrated
reduced prefrontal cortex activation during task performance compared to healthy