Motor Imagery EEG neurofeedback skill acquisition in the context of declarative interference and sleep

Abstract

Motor imagery (MI) practice in combination with neurofeedback (NF) is a promising supplement to facilitate the acquisition of motor abilities and the recovery of impaired motor abilities following brain injuries. However, the ability to control MI NF is subject to a wide range of inter-individual variability. A substantial number of users experience difficulties in achieving good results, which compromises their chances to benefit from MI NF in a learning or rehabilitation context. It has been suggested that context factors, that is, factors outside the actual motor task, can explain individual differences in motor skill acquisition. Retrospective declarative interference and sleep have already been identified as critical factors for motor execution (ME) and MI based practice. Here, we investigate whether these findings generalize to MI NF practice.Three groups underwent three blocks of MI NF practice each on two subsequent days. In two of the groups, MI NF blocks were followed by either immediate or delayed declarative memory tasks. The control group performed only MI NF and no specific interference tasks. Two of the MI NF blocks were run on the first day of the experiment, the third in the morning of the second day. Significant within-block NF gains in mu and beta frequency event-related desynchronization (ERD) where evident for all groups. However, effects of sleep on MI NF ERD were not found. Data did also not indicate an impact of immediate or delayed declarative interference on MI NF ERD.Our results indicate that effects of sleep and declarative interference context on ME or MI practice cannot unconditionally be generalized to MI NF skill acquisition. The findings are discussed in the context of variable experimental task designs, inter-individual differences, and performance measures.

The Impact of Context on EEG Motor Imagery Neurofeedback and Related Motor Domains

“…MI practice resulted in an additional performance increase after sleep compared to consolidation over the day but only for a complex movement sequence [70]. The finding that the effects were restricted to the complex movement is partially in line with recent findings on MI NF performance on a simple MI task that neither indicate the presence of an early boost nor of sleep-related performance gains [71]. Interestingly, in contrast to the relatively rich body of research on sleep, the impact of sleep deprivation on motor performance remains unclear [72].…”

“…However, no evidence for any adverse effect of various verbal and non-verbal declarative interference tasks on ME task performance was found in a more recent study [77]. In line with the latter, we found no evidence for any impact of declarative interference on MI NF performance, neither over wakefulness nor after a night of sleep [71].…”