Table 1.

Summary of EEG/MEG studies investigating high-frequency neural oscillations in patients with chronic schizophrenia and healthy controls during visual perceptual tasks.

Paradigm	Imaging modality	Oscillatory measure	Parameter assessed	Main findings	References
Steady state stimulation	EEG	Evoked	Amplitude	17–30 Hz range amplitude decrease over occipital electrodes	Krishnan et al., 2005
Backward masking	EEG	Evoked	Amplitude	30–40 Hz range amplitude decrease across electrodes	Wynn et al., 2005
	EEG	Evoked	Amplitude/Latency	30–35 Hz range amplitude decrease over parieto-occipital electrodes	Green et al., 2003
Oddball detection	EEG	Evoked	Inter-trial phase-locking	Decreased 30–38 Hz range phase-locking over parieto-occipital electrodes	Spencer et al., 2008
Illusory square	EEG	Evoked	Inter-trial phase-locking	Decreased 28–35 Hz range phase-locking over parieto-occipital electrodes	Spencer et al., 2004
		Induced	Inter-trial phase-locking	i) Decreased 30–45 Hz range phase-locking
				ii) Decrease in peak phase-locking frequency (at 22–26 Hz cf. controls) over occipital and parietal electrodes in response-locked analysis
		Evoked	Inter-trial phase-locking	i) Decreased 24–48 Hz phase-locking
				ii) Decrease in peak phase-locking frequency in response to ‘No-Square’ stimuli over occipital and central electrodes	Spencer et al., 2003
		Induced	Inter-sensor phase-coherence	Long-range 20–26 Hz range decrease in phase-locking
				Inter-hemispheric decrease in peak phase-coherence frequency (37–44 Hz cf. 48–57 Hz) particularly over posterior electrodes
Mooney faces	MEG	Evoked	Amplitude	i) 25–140 Hz range amplitude decrease, especially pronounced in the 60–140 Hz range	Grützner et al., 2013
				ii) 25–60 Hz range fronto-central amplitude increase
			Inter-trial phase-locking	Decreased 60–140 Hz range phase-locking
		Induced	Amplitude	60–140 Hz range amplitude decrease over occipital sensors
	EEG	Induced	Amplitude	Insignificant difference in the 40–70 Hz range across electrodes	Uhlhaas et al., 2006a
			Inter-trial phase-locking	Decreased and delayed onset latency of 20–55 Hz range phase-locking
			Inter-sensor phase-coherence	Decreased 20–30 Hz phase-coherence between fronto-temporal and parieto-occipital electrodes

Main findings of these studies are reported in brief, highlighting the frequency range of significant effects observed in patients cf. healthy controls.