Early switching between movement types: indication of predictive control?
In everyday life, we frequently alternate between performing discrete and rhythmic movements. When performing a periodic movement, two distinct movement types can be distinguished: highly harmonic vs. discrete-like. The harmonicity of the movement is used to classify it as one or the other. We asked: (1) whether the frequency at which a periodic movement is performed affects the harmonicity of the resultant movement; and (2) what underlies switching between these movement types. To answer these questions, we studied horizontal flexion/extension forearm movements in 13 young adults over a wide range of frequencies. Movements were performed either at a fixed frequency, or at gradually increasing or decreasing target frequencies. We found movement harmonicity to depend on the frequency of the movement. Furthermore, we found a reverse hysteresis behavior, where participants switched movement type in anticipation of the future-required frequency. These findings suggest that predictive control is employed in switching between movement types.
Department of Biomedical Engineering, Ben-Gurion University of the Negev, Beer Sheva, Israel. shelly@huji.ac.il
S
S
Levy-Tzedek
M Ben
MB
Tov
A
A
Karniel
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D010507:Periodicity; D011597:Psychomotor Performance / Q000502:physiology*; D055815:Young Adult