Neurofeedback of Theta and Beta Frequencies: Effects on Selective Attention and Response Inhibition

Despite the widespread employment of electroencephalographic (EEG) neurofeedback (NF) in clinical and cognitive enhancement contexts, its impact on selective attention and response inhibition remains poorly understood. The present research investigated the influence of theta frequency suppression and low-beta frequencies enhancement on these cognitive functions. A first study investigated the differential impact of the sensorimotor rhythm (SMR) and beta1 amplitude enhancement NF on event-related potentials (ERP) and behavioral measures indexing selective attention and response inhibition in the three-stimuli oddball and in the cued-Go/Nogo tasks. The learning curves evinced training-specific amplitude increments in the beta1 but not in the SMR frequency. However, SMR NF was associated with increased Go-P3 amplitude, decreased mean RT and RT SD, while control and beta1 NF were associated with increased false alarm rates in the cued-Go/Nogo. A second study attempted to understand whether performance increments in selective attention and response inhibition could be explained by theta suppression NF when compared to beta1 NF in the same task conditions. Within-session theta amplitude was decreased in theta relative to beta1 NF in passive resting state but not during feedback trials. However, for both theta and beta1 NF there was no evidence of training-specific amplitude changes relative to controls. Regarding selective attention, the mean RT was increased following beta1 NF and decreased after theta NF but not in the same task conditions. This study also failed to provide evidence of increased or decreased performance in response inhibition. In conclusion, the present research was not conclusive regarding the NF conditions that might have contributed to improvements in target processing efficiency and cancellation of a previously prepared response in previous studies. Specific proposals to address several methodological limitations that might have hindered the possibility of detecting frequency-specific amplitude changes and cognitive improvements were advanced