Table 5. Broad movement-related gamma ERS.
These studies represent a non-systematic selection of relevant studies that are presented in chronological order. GPi: internal segment of the globus pallidum; STN: subthalamic nucleus; M1: primary motor cortex; SMA: supplementary motor area; ECoG:electrocorticography; EEG: electroencephalography; ET: essential tremor; PD: Parkinson’s disease; OFF: off dopaminergic medication; ON: on dopaminergic medication; FFTL fast fourier transform; ERS: event-related synchronisation.
| Study | Location | Disorder | Medication | Methods | Main Findings |
|---|---|---|---|---|---|
| Lofredi et al., 2018 | STN | PD | ON + OFF | complex Morlet wavelet convolution (7 cycles, from 1-100 Hz, 1 Hz resolution) | broad STN gamma positively correlates with maximal velocity and negatively with symptom severity, gamma bursts correlate with average power and increase with larger movements, |
| Fischer et al., 2017 | STN | PD | ON | Filter Hilbert method (from 50-120 Hz, bandpass filtering the data in 10 Hz wide bands shifted by 2 Hz) | broad STN gamma increases when finger taps are successfully stopped |
| Brücke et al., 2013 | ventral intermediate nucleus (thalamus) | ET | OFF | short-time FFT (~0.41 s Hann windows, ~25% overlap, 2.4 Hz resolution) | movement-related gamnma activity is lateralised to the contralateral thalamus, baseline gamma activity correlates with reaction times suggesting pre-cue gamma may relate to arousal |
| Tan et al., 2013a | STN | PD | ON | complex Morlet wavelet convolution | broad power increase in the gamma band (55-90 Hz), gamma power was further enhanced during grips with greater effort |
| Tan et al., 2013b | STN | PD | ON + OFF | complex Morlet wavelet convolution | broad gamma (55-375 Hz) was reduced concomitant with decreasing grip force |
| Brücke et al., 2012 | GPi | dystonia | OFF | short-time FFT(0.512 s Hann windows, ~80% overlap, ~1.95 Hz resolution) | pallidal LFPs were recorded during a choice-reaction-time task, broad contralateral gamma band (35-105 Hz) ERS occurred at movement onset, the larger and faster the movement, the stronger the gamma ERS |
| Anzak et al., 2012 | STN | PD | ON + OFF | method unclear | broad gamma activity (55-375 Hz) and grip force are correlated, broad gamma increases with activities encoding maximal effort grips but gamma increases only have a trivial contribution to reaction time shortening |
| Litvak et al., 2012 | STN, M1 | PD | ON + OFF | multitaper method(0.4 s windows, ~87.5% overlap, 5 Hz resolution, 3 tapers used for gamma) | broad gamma peaks (60-90 Hz) in M1, STN and coherence between the two, gamma power increased with movement and levodopa, STN gamma drives cortical gamma |
| Ray et al., 2012 | STN | PD | ON | Hermite functions analysis (3 s windows aligned to movement onset, time-frequency area A/2 = 5, from 6-100 Hz, resolution: 10 ms x 0.33 Hz) | gamma oscillations (60-100 Hz) respond robustly to stop-signals as well as go-signals |
| Joundi et al., 2012 | STN | PD | ON | Hermite functions analysis (time-frequency area A/2 = 5, resolution: 167 ms x 2.7 Hz) | gamma ERS is more pronounced during fast arm reaching movements |
| Anzak et al., 2011 | STN | PD | ON | short-time FFT (1 s windows,1 Hz resolution) | broad gamma increase (30-95 Hz) during verbal fluency tasks after controlling for motor output |
| Huo et al., 2011 | M1 | healthy children | OFF | complex Morlet wavelet convolution | broadband gamma increase (65-150 Hz) contralateral and ipsilateral to finger movements |
| Brücke et al., 2008 | GPi | dystonia | OFF | short-time FFT (0.41 s Hann windows, ~25% overlap,2.4 Hz resolution) | prominent, perimovement increase in 60-80 Hz activity contralateral to movement |
| Cheyne et al., 2008 | M1 | healthy adults | OFF | complex Morlet wavelet transform (7 cycles, from 2-110 Hz, 21 Hz resolution) | broad gamma oscillations (65-80 Hz) were localised to the contralateral M1 during self-paced movements, high gamma activity increased only during movement, gamma activity is task-dependent |
| Ball et al., 2008 | M1, SMA (ECoG, EEG) | epilepsy, healthy adults | OFF | multitaper method (0.32 s window, ~87.5% overlap, 2 tapers) | broad gamma increase (60-90 Hz) over the sensorimotor cortex contralateral to the side of arm movement, gamma activity started at movement onset and became more pronounced at movement end |
| Androulidakis et al., 2007 | STN | PD, ET | ON + OFF | short-time FFT (~1 s Hann windows, ~99% overlap, ~1 Hz resolution) | bilateral, symmetrical broad gamma band increase occurred around movement onset and was more pronounced on levodopa |