Reply: On assessing neurofeedback effects: should double-blind replace neurophysiological mechanisms?

We agree that, strictly speaking, the results of our study (Schabus et al., 2017) do not allow generalizing the negative findings reported in primary insomnia to other NFT applications. Yet, what is disturbing is the fact that even misperception insomniacs (i.e. participants without any objectively quantifiable sleep problems) show unaltered EEG activity [in the same 12–15 Hz range; sensorimotor rhythm (SMR)] minutes after NFT sessions ended. At least we would have expected a sustained effect in this subgroup because they should not suffer from severe learning impairments. Surprisingly, these findings contradicted earlier reports from our own laboratory (Hoedlmoser et al., 2008; Schabus et al., 2014), where we added a healthy and younger control group and verified that participants achieved similar SMR enhancements during NFT training blocks (14–28%) as found earlier (15–25%; Schabus et al., 2014).