Transcranial Magnetic Stimulation at M1 disrupts cognitive networks in schizophrenia

• Published in: Schizophrenia research Vol. 93; no. 1; pp. 334 - 344
• Main Authors: Levit-Binnun, Nava, Handzy, Nestor Z, Moses, Elisha, Modai, Ilan, Peled, Avi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-07-2007; Elsevier Science
• Subjects: Adult; Adult and adolescent clinical studies; Attention - physiology; Biological and medical sciences; Cognition; Cognition - physiology; Female; Humans; Male; Medical sciences; Middle Aged; Motivation; Motor Activity - physiology; Motor control; Motor Cortex - physiopathology; Nerve Net - physiology; Perception; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychoses; Schizophrenia; Schizophrenia - diagnosis; Schizophrenia - physiopathology; Schizophrenic Psychology; Time Perception - physiology; Timing; Transcranial Magnetic Stimulation; Transcranial Magnetic Stimulation; Schizophrenia; Perception; Cognition; Timing; Motor control; Psychosis; Human; Transcranial magnetic stimulation; Magnetic stimulus; Motricity
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2007.02.019

Abstract Transcranial Magnetic Stimulation (TMS) is rapidly gaining acceptance as a non-invasive probe into brain functionality. We utilize TMS to study the connectivity of a simple motor network in patients of schizophrenia ( N = 19), and in healthy control subjects ( N = 9). TMS was used in an externally paced finger tapping task, perturbing the internal network oscillations invoked by the finger motion as it keeps pace with a metronome. TMS perturbations were synchronized to the metronome and applied to the network at the level of the primary motor cortex (M1). Contrary to initial expectations, TMS did not affect the sensorimotor synchronization of subjects with schizophrenia or their tapping accuracy. TMS did cause extreme deviations in the finger's trajectory, and altered the timing perceptions of subjects with schizophrenia. Additionally, it invoked high-level deficiencies related to attention and volition in the form of lapses, implying that the connectivity between modules in the brain that underlie motor control, sensorimotor synchronization, timing perception and awareness of action, can be disrupted by TMS in subjects with schizophrenia, but not in healthy subjects. The ability to disrupt high level network functions with perturbations to the lower level of M1 supports models describing deficits in connectivity of distributed networks in the brains of schizophrenia patients. It also demonstrates the use of TMS to probe connectivity between components of such networks.