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Updated: Jun 1, 2025

Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
Lower perturbational complexity index after transcranial magnetic stimulation in schizophrenia patients
Vicente Molina1, Inés Fernández-Linsenbarth2, Rosa Beño-Ruiz-de-la-Sierra2
1Psychiatry Department, School of Medicine, University of Valladolid, Valladolid, Spain; Psychiatry Service, University Clinical Hospital of Valladolid, Valladolid, Spain.
Background:
Informational integration and differentiation of the cortex can be tested by methods such as the perturbational complexity index (PCI) combined with TMS-induced activity perturbation. The PCI is obtained by stimulating the cortex with TMS and measuring the resulting spatiotemporal cortical responses with high-density EEG.
Methods:
We have compared PCI between 26 patients with schizophrenia (15 males), 15 of them First Episode (FE) (7 males), and 22 healthy controls (12 males).
Results:
Values of PCI were significantly lower in patients with schizophrenia, as well as in FE considered alone. There was no significant relation between anomalous self-experiences or symptoms and PCI values in the patients: PCI values were unrelated to treatment doses or illness duration.
Conclusions:
Our data suggest that spatiotemporal cortical responses to TMS pulses are reduced in patients regarding variability or spatial extension, which could imply a lower capacity for sustaining informational complexity.

