Pdf Level 3 Unit 8 P1

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In this report, Kogenemaru et al examined whether neurofeedback about the amplitude of motor evoked potentials could lead participants to modulate the excitability of intracortical circuits within M1. They showed that the group receiving neurofeedback had a greater change in SICI than the control group. This apparent change in the excitability of intracortical circuits also resulted in shorter reaction times in a choice task. The study is interesting but I have a few issues with the paper in its current form (see below). Major comments: 1) It is not clearly described in the manuscript how the ratios were calculated. Change rate = (post0/pre)-1. Are post0 and pre values of the MEPs obtained with paired-pulses or the ratios? If they are ratios, …show more content…

Less inhibition should result in positive rates of change. Given the instruction is to make circles smaller, the authors asked them to inhibit more, is that correct? If you have more intracortical inhibition, why are RTs faster? For example, anodal tDCS shortens RT (Hummel et al. 2006, BMC Neuroscience) and decreases SICI (inducing larger MEP ratios, Kidgell et al. 2013, Neural Plasticity). Assuming participants can change intracortical excitability at will and this method is perhaps equivalent to using non-invasive stimulation (anodal tDCS), it would be expected that RT would become larger. 5) Participants are allegedly learning how to control intracortical activity within M1, thus some measure of performance during acquisition would be good (e.g. change in circle size over time). 6) It would be important to show the exact RT values for both groups before and after the intervention. In addition, the percentage of trials with incorrect responses should be analysed formally so that the RT data can be more meaningfully interpreted. For example, are there less errors for the intervention group in comparison to the control group? If you have more inhibition, I would expect less errors. Also, it was not clear in the results that improvement in RT was specific to the left-hand, but this mentioned in the discussion (line …show more content…

However, an inspection of Figure 3b suggests a qualitative similar pattern of results. I would suggest that the authors conduct a non-parametric permutational anova or one of the robust methods put forward by Wilcox (2012) to analyse the data. Because we are looking at ratios here, I wouldn’t be surprised if the non-significant results turned-out significant when you analyse the data with methods that are more robust to deal with extreme values and departures from normality. This could change the interpretation and discussion of the

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