Τίτλος:
Brain functional connectivity during the experience of thought blocks in
schizophrenic patients with persistent auditory verbal hallucinations:
An EEG study
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Thought blocks (TBs) are characterized by regular interruptions in the
stream of thought. Outward signs are abrupt and repeated interruptions
in the flow of conversation or actions while subjective experience is
that of a total and uncontrollable emptying of the mind. In the very
limited bibliography regarding TB, the phenomenon is thought to be
conceptualized as a disturbance of consciousness that can be attributed
to stoppages of continuous information processing due to an increase in
the volume of information to be processed. In an attempt to investigate
potential expression of the phenomenon on the functional properties of
electroencephalographic (EEG) activity, an EEG study was contacted in
schizophrenic patients with persisting auditory verbal hallucinations
(AVHs) who additionally exhibited TBs. In this case, we hypothesized
that the persistent and dense AVHs could serve the role of an increased
information flow that the brain is unable to process, a condition that
is perceived by the person as TB. Phase synchronization analyses
performed on EEG segments during the experience of TBs showed that
synchrony values exhibited a long-range common mode of coupling (grouped
behavior) among the left temporal area and the remaining central and
frontal brain areas. These common synchrony-fluctuation schemes were
observed for 0.5 to 2 s and were detected in a 4-s window following the
estimated initiation of the phenomenon. The observation was frequency
specific and detected in the broad alpha band region (6-12 Hz). The
introduction of synchrony entropy (SE) analysis applied on the
cumulative synchrony distribution showed that TB states were
characterized by an explicit preference of the system to be functioned
at low values of synchrony, while the synchrony values are broadly
distributed during the recovery state. Our results indicate that during
TB states, the phase locking of several brain areas were converged
uniformly in a narrow band of low synchrony values and in a distinct
time window, impeding thus the ability of the system to recruit and to
process information during this time window. (C) 2014 Elsevier B. V. All
rights reserved.
Συγγραφείς:
Angelopoulos, Elias
Koutsoukos, Elias
Maillis, Antonis and
Papadimitriou, George N.
Stefanis, Costas
Περιοδικό:
Schizophrenia Research
Λέξεις-κλειδιά:
Thought blocks; Auditory verbal hallucinations; Schizophrenia; EEG;
Synchrony; Connectivity
DOI:
10.1016/j.schres.2014.01.036
