Default Mode Network alterations in alexithymia: an EEG power spectra and connectivity study

Abstract

Recent neuroimaging studies have shown that alexithymia is characterized by functional alterations in different brain areas [e.g., posterior cingulate cortex (PCC)], during emotional/social tasks. However, only few data are available about alexithymic cortical networking features during resting state (RS). We have investigated the modifications of electroencephalographic (EEG) power spectra and EEG functional connectivity in the default mode network (DMN) in subjects with alexithymia. Eighteen subjects with alexithymia and eighteen subjects without alexithymia matched for age and gender were enrolled. EEG was recorded during 5 min of RS. EEG analyses were conducted by means of the exact Low Resolution Electric Tomography software (eLORETA). Compared to controls, alexithymic subjects showed a decrease of alpha power in the right PCC. In the connectivity analysis, compared to controls, alexithymic subjects showed a decrease of alpha connectivity between: (i) right anterior cingulate cortex and right PCC, (ii) right frontal lobe and right PCC, and (iii) right parietal lobe and right temporal lobe. Finally, mediation models showed that the association between alexithymia and EEG connectivity values was directed and was not mediated by psychopathology severity. Taken together, our results could reflect the neurophysiological substrate of some core features of alexithymia, such as the impairment in emotional awareness.

Random Forest Classification of Alcohol Use Disorder Using EEG Source Functional Connectivity, Neuropsychological Functioning, and Impulsivity Measures

“…The DMN regions analyzed in the study are posterior cingulate cortex (PCC), anterior cingulate cortex (ACC), inferior parietal cortex (IPL), prefrontal cortices (PFC), lateral temporal cortex (LTC), and hippocampal formation (HCF) ( Table 2 and Figure 1), in line with the fc-MRI and fc-EEG studies [58,[78][79][80]. More information about the DMN seed selection is described in our recent publication with fc-MRI in the same sample as the current study [54].…”

“…The eLORETA, a linear, discrete, three-dimensional weighted minimal norm inverse solution method [42], enables the non-invasive examination of intra-cortical interactions with interpretable spatial resolution [57]. Specifically, the lagged phase synchronization of the eLORETA is predominantly used to assess functional connectivity (e.g., [45,58]), as it represents physiological (neural) information and is minimally affected by the low spatial resolution [42]. To our knowledge, the only study that is available on resting state EEG source (eLORETA) connectivity on alcoholism [59] has examined a limited number of AUD patients (N = 11) who had excessive craving and withdrawal symptoms and found a dense array of hyperconnectivity (i.e., increased FC) in theta band across the regions of reward and executive processing networks.…”

The Symptom-Checklist-K-9 (SCL-K-9) Discriminates between Overweight/Obese Patients with and without Significant Binge Eating Pathology: Psychometric Properties of an Italian Version

“…Lastly, we used only self-reported measures; in the future, the performance of the SCL-K-9 to classify patients with and without mental disorders should be analyzed using structured clinical interviews. Indeed, although the SCL-90-R is an adequate instrument to assess general psychopathology, it does not diagnose a mental disorder [60].…”

The Association among Default Mode Network Functional Connectivity, Mentalization, and Psychopathology in a Nonclinical Sample: An eLORETA Study

“…In order to evaluate the association between mentalization, psychopathology, and connectivity in the DMN, 12 regions of interest (ROIs) were defined according to Thatcher et al [25] This procedure has been also recently used to investigate DMN alterations in alexithymia [41]. Detailed eLORETA Montreal Neurological Institute coordinates of the ROIs have been reported elsewhere [41,42].…”

“…Detailed eLORETA Montreal Neurological Institute coordinates of the ROIs have been reported elsewhere [41,42]. According to Canuet et al [43], the "single nearest voxel" option (i.e., each ROI consisted of a single voxel, the closest to each seed) was chosen.…”