Abnormal visuomotor processing in schizophrenia

Abstract

Subtle disturbances of visual and motor function are known features of schizophrenia and can greatly impact quality of life; however, few studies investigate these abnormalities using simple visuomotor stimuli. In healthy people, electrophysiological data show that beta band oscillations in sensorimotor cortex decrease during movement execution (event-related beta desynchronisation (ERBD)), then increase above baseline for a short time after the movement (post-movement beta rebound (PMBR)); whilst in visual cortex, gamma oscillations are increased throughout stimulus presentation. In this study, we used a self-paced visuomotor paradigm and magnetoencephalography (MEG) to contrast these responses in patients with schizophrenia and control volunteers. We found significant reductions in the peak-to-peak change in amplitude from ERBD to PMBR in schizophrenia compared with controls. This effect was strongest in patients who made fewer movements, whereas beta was not modulated by movement in controls. There was no significant difference in the amplitude of visual gamma between patients and controls. These data demonstrate that clear abnormalities in basic sensorimotor processing in schizophrenia can be observed using a very simple MEG paradigm.

The effect of physical fatigue on oscillatory dynamics of the sensorimotor cortex

“…) and schizophrenia (Robson et al . ). Judicious design of study protocols is therefore essential to ensure the PMBR is not affected by the experimental procedures, particularly when investigating disorders in which susceptibility to fatigue represents a common symptom.…”

“…For example, PMBR is greater in healthy controls than patients with schizophrenia, and the magnitude of PMBR in patients correlates with persistent symptoms of disease (Robson et al . ). In individuals with Parkinson's disease, where movements are limited and poorly controlled, resting beta oscillations are increased and the relative magnitude of MRBD and PMBR are reduced in amplitude compared with healthy controls (Pollok et al .…”

A new generation of magnetoencephalography: Room temperature measurements using optically-pumped magnetometers

“…MEG is capable of tracking the formation and dissolution of electrophysiological networks in real time and with high spatial precision ( O'Neill et al, 2015 , Troebinger et al, 2014a ). Because of this, MEG is now having impact on our understanding of the healthy brain, and on a wide range of clinical research areas ranging from neurodevelopment ( Ciesielski and Stephen, 2014 ) to severe psychoses ( Robson et al, 2016 , Uhlhaas and Singer, 2010 ). The further development of MEG technology is therefore an important and evolving focus.…”

Imaging human cortical responses to intraneural microstimulation using magnetoencephalography

“…In the Kelly et al study they used 200 trials of 1 s stimulation, whereas here we used 80 trials. Our choice of 80 was to optimise the experiment for capturing the modulation in beta power, which in the sensorimotor system takes several seconds to return to baseline after an event Fry et al, 2016;Pakenham et al, 2018;Robson et al, 2016), and so to gain an adequate inter-trial interval, the total number of trials is fewer. Assuming zero trials rejected, the Kelly et al study has a 58% signal to noise ratio (SNR) improvement over our paradigm and this may be crucial to see such effects.…”