7 Computational EEG Analysis for the Diagnosis of Psychiatric …
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In addition, specific symptoms were related to different neural activity at different
cortical regions.
Recently, a study that examined the source level functional connectivity of restingstate EEG reflected source level abnormalities in patient with PTSD [121]. In this
study, theta and low beta frequency bands were significantly impaired in patients
with PTSD compared with healthy control. As for the nodal clustering coefficients,
that of the theta band negatively correlated with rumination and re-experience symptom scores, while that of the low beta band correlated positively with anxiety and
pain severity. In theta frequency band, the right posterior cingulate cortex and left
temporal cortex were significantly correlated with impact event scale of patients with
PTSD. As evidenced in Fig. 7.7, brain anatomy-based information can be given in
source-level EEG functional connectivity analysis. It could be a promising biomarker
of PTSD as well as other psychiatric illness, as not only a disease classifier but
also treatment response indicator of various psychotropic medication and cognitive
behavioral treatment.
7.3.4.2 Obsessive Compulsive Disorder (OCD)
Patients with obsessive compulsive disorder (OCD) are characterized by inclinations
to monitor their thoughts and behaviors with a desire to maintain control. Neurophysiological studies on OCD have focused on their tendency to monitor performance
and patterns in processing errors. In particular, the error-related negativity (ERN), a
neural alteration that occurs 50–100 ms after committing errors, has been of special
interest. The ERN is thought to reflect activity of the response-monitoring system
and greater magnitude ERNs are observed in patients with OCD [28, 51]. A major
advantage of the ERN is that its enhancement in OCD seems to be independent of
pharmacological or psychological interventions [23, 127]. In addition, similar patterns have been identified in subclinical OCD symptoms [99, 118], and non-affected
first-degree relatives of patients with OCD, which suggest the possibility of a biological influence [13, 113].
Studies examining cortical activities in OCD have reported significant results as
well. A study by Kopˇ rivová and colleagues, who applied low-resolution electromagnetic tomography (LORETA) and independent component analysis (ICA), identified
medial frontal hyperactivation in OCD [65]. In addition, patients with OCD were
found to have greater relative power of lower alpha (8–10 Hz) frequency band in the
left hemisphere at rest and during presentations of neutral, aversive, and OCD-related
pictures. These changes in hemispheric alpha band has been proposed as biomarker
for increased avoidance motivation in patients with OCD [45].
165
In addition, specific symptoms were related to different neural activity at different
cortical regions.
Recently, a study that examined the source level functional connectivity of restingstate EEG reflected source level abnormalities in patient with PTSD [121]. In this
study, theta and low beta frequency bands were significantly impaired in patients
with PTSD compared with healthy control. As for the nodal clustering coefficients,
that of the theta band negatively correlated with rumination and re-experience symptom scores, while that of the low beta band correlated positively with anxiety and
pain severity. In theta frequency band, the right posterior cingulate cortex and left
temporal cortex were significantly correlated with impact event scale of patients with
PTSD. As evidenced in Fig. 7.7, brain anatomy-based information can be given in
source-level EEG functional connectivity analysis. It could be a promising biomarker
of PTSD as well as other psychiatric illness, as not only a disease classifier but
also treatment response indicator of various psychotropic medication and cognitive
behavioral treatment.
7.3.4.2 Obsessive Compulsive Disorder (OCD)
Patients with obsessive compulsive disorder (OCD) are characterized by inclinations
to monitor their thoughts and behaviors with a desire to maintain control. Neurophysiological studies on OCD have focused on their tendency to monitor performance
and patterns in processing errors. In particular, the error-related negativity (ERN), a
neural alteration that occurs 50–100 ms after committing errors, has been of special
interest. The ERN is thought to reflect activity of the response-monitoring system
and greater magnitude ERNs are observed in patients with OCD [28, 51]. A major
advantage of the ERN is that its enhancement in OCD seems to be independent of
pharmacological or psychological interventions [23, 127]. In addition, similar patterns have been identified in subclinical OCD symptoms [99, 118], and non-affected
first-degree relatives of patients with OCD, which suggest the possibility of a biological influence [13, 113].
Studies examining cortical activities in OCD have reported significant results as
well. A study by Kopˇ rivová and colleagues, who applied low-resolution electromagnetic tomography (LORETA) and independent component analysis (ICA), identified
medial frontal hyperactivation in OCD [65]. In addition, patients with OCD were
found to have greater relative power of lower alpha (8–10 Hz) frequency band in the
left hemisphere at rest and during presentations of neutral, aversive, and OCD-related
pictures. These changes in hemispheric alpha band has been proposed as biomarker
for increased avoidance motivation in patients with OCD [45].