Effects of self-action observation on standing balance learning: A change of brain activity detected using functional near-infrared spectroscopy

BACKGROUND: Studies suggest that the observation of others' actions leads to enhanced motor skill learning. OBJECTIVE: We examined whether others' or self-action observation is effective for standing balance learning. In addition, we examined cortical activation during action observation using functional near-infrared spectroscopy. METHODS: Thirty-nine healthy young subjects were assigned randomly to the Control, Other-Observation (O-O), and Self-Observation (S-O) groups. The subjects learned to stand on a tilting platform while maintaining a horizontal position. The Control group alternated each trial with a rest period. The O-O and S-O groups were provided with information related to their performance during the rest period: the O-O group observed another person, while the S-O group observed their previous performance. Cortical activation was assessed by changes of hemoglobin oxygenation (oxyHb). RESULTS: A 2-way analysis of variance with repeated measures on balance performance revealed a significant difference in post-training (p < 0.05) and retention (p < 0.01) only in the S-O group. And an increase of oxyHb levels at post-training in the S-O group was observed in the supplementary motor area. CONCLUSION: Self-action observation improved standing balance and brain activity during training and at 24 h after training.