Comparison of whole-body sensorimotor skill learning between strength athletes, endurance athletes and healthy sedentary adults

Complex sequential learning is not facilitated by transcranial direct current stimulation over DLPFC or M1

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique which was found to have a positive modulatory effect on online sequence acquisition or offline motor consolidation, depending on the relative role of the associated brain region. Primary motor regions (M1) and dorsolateral prefrontal cortices (DLPFC) have both been related to sequential learning. However, research so far did not systematically disentangle their differential roles in online and offline learning especially in more complex sequential paradigms. In this study, the influence of anodal M1 leg area-tDCS and anodal DLPFC-tDCS applied during complex sequential learning (online and offline) was investigated using a complex whole body serial reaction time task (CWB-SRTT) in 42 healthy volunteers. TDCS groups did not differ from sham tDCS group regarding their response and reaction time (online) and also not in terms of overnight consolidation (offline). Sequence specific learning and the number of recalled items also did not differ between groups. Results may be related to unspecific parameters such as timing of the stimulation or current intensity but can also be attributed to the relative role of M1 and DLPFC during early complex learning. Taken together, the current study provides preliminary evidence that M1 leg area or DLPFC modulation by means of tDCS does not improve complex sequential skill learning. SIGNIFICANCE STATEMENT: Understanding motor learning is helpful to deepen our knowledge about the human ability to acquire new skills. Complex sequential learning tasks have only been studied, sparsely, but are particularly mimicking challenges of daily living. The present study studied early motor learning in a complex serial reaction time task while transcranial direct current stimulation (tDCS) was either applied to leg primary motor cortex or bilateral dorsolateral prefrontal cortex. TDCS did not affect sequential learning, neither directly during performance nor in terms of sequence consolidation. Results provide preliminary information that M1 or bilateral DLPFC modulation does not improve early complex motor learning.

Whole-body sensorimotor skill learning in football players: No evidence for motor transfer effects

Besides simple movement sequences, precise whole-body motor sequences are fundamental for top athletic performance. It has long been questioned whether athletes have an advantage when learning new whole-body motor sequences. In a previous study, we did not find any superior learning or transfer effects of strength and endurance athletes in a complex whole-body serial reaction time task (CWB-SRTT). In the present study, we aimed to extend this research by increasing the overlap of task requirements between CWB-SRTT and a specific sports discipline. For this purpose, we assessed differences between football players and non-athletes during motor sequence learning using CWB-SRTT. 15 non-athletes (CG) and 16 football players (FG) performed the CWB-SRTT over 2 days separated by one week. Median reaction times and movement times were analyzed as well as differences in sequence-specific CWB-SRTT learning rates and retention. Our findings did not reveal any differences in sequence-specific or non-sequence-specific improvement, nor retention rates between CG and FG. We speculate that this might relate to a predominately cognitive-induced learning effect during CWB-SRTT which negates the assumed motor advantage of the football players.