Effect of action observation vs. combined action observation and execution on timing of reaching movement sequences
Silvi Frenkel-Toledo1,2, Hila Wides3, Neta Avishar3, Hodaya Shtachelberg3, Nechama Hermon3 and Zvi Kozol1
1 Department Physiotherapy, Faculty of Health Sciences, Ariel University, Ariel, Israel
2 Department of Physiotherapy, Loewenstein Hospital, Raanana, Israel
3 Physiotherapy student, Department of Physiotherapy, Faculty of Health Sciences, Ariel University, Ariel, Israel
Observing the actions of others can improve motor performance. The effects of action observation (AO) on motor performance can be modulated by different factors. The effects of AO versus combined AO and action execution have not been fully resolved. Twenty-four healthy subjects were randomly instructed to either observe reaching movements (RM) sequences towards five lighted units with the intention of reproducing the same sequence as fast and as accurately as possible (AO group), or to observe the RM sequence with the intention of reproducing the same sequence as fast and as accurately as possible and combining action execution with the AO (AO+EX). Subjects` performance was tested before and immediately after the AO, and retested after 24 hours. During the pre-test, post-test, and retest, the subject performed RMs towards the units, which were activated in the same order as the observed sequence. Occasionally, the sequence order was changed by beginning the sequence with a different activated unit. The outcome measures were average response time of the RMs during the sequences, difference between the response time of the unexpected and expected RMs, and percent of failures to reach the target within one second. The average response time and the difference between the response time of the unexpected and expected RMs improved in both groups at post-test and retest compared to pre-test. The percent of failures across groups was higher in the pre-test and post-test compared to retest. Our findings suggest that combining action execution with AO in a RM sequence task in the current setup does not improve subsequent performance more than AO alone. Performance stabilization of the sequence in the retest was shown in comparison to the post-test in both groups, indicating that the memory representation learned through observation with or without combining action execution was consolidated.
Keywords: Action observation, Action execution, Instruction