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. 2019 Apr 8;8:e40145. doi: 10.7554/eLife.40145

Figure 2. Frequency responses and phase delays to artificial motor errors.

(A) Example force (black) and cursor (yellow) angular velocity traces in the presence of a 2 Hz perturbation (green) when no feedback delay was added. The force response and perturbation sum to produce large fluctuations in cursor velocity. (B) Comparable data with a feedback delay of 200 ms. In this condition, force responses cancel the perturbation leading to an attenuation of intermittency. (C) Power spectra of cursor angular velocity with 1–5 Hz perturbations and no feedback delay. Analysis based on 10 s windows beginning 5 s after trial start. Average of 8 subjects. See also Figure 2—figure supplement 1. (D) Power spectra of cursor angular velocity with 1–5 Hz perturbations and 200 ms feedback delay. (E) Cursor amplitude response to 1–5 Hz perturbations with no feedback delay (blue) and 200 ms feedback delay (red) for individual subjects. Also shown is the average ± s.e.m. of 8 subjects. (F) Power spectra of force angular velocity with 1–5 Hz perturbations and no feedback delay. See also Figure 2—figure supplement 2. (G) Power spectra of force angular velocity with 1–5 Hz perturbations and 200 ms feedback delay. (H) Force amplitude response to 1–5 Hz perturbations with no feedback delay (blue) and 200 ms feedback delay (red). Also shown is average ± s.e.m. of 8 subjects. (I) Intrinsic phase delay of force response to 1–5 Hz perturbations with no feedback delay (blue) and 200 ms feedback delay (red). Also shown is average ± s.e.m. of 8 subjects. (J) Power spectrum of finger forces generated in the feedforward task with auditory cues at 15 Hz. Average of 8 subjects. See also Figure 2—figure supplement 3. (K) Force amplitude response to auditory cues in the feedforward task. Also shown is average ± s.e.m. of 8 subjects. All analyses based on a 10 s windows beginning 5 s after trial start.

Figure 2—source data 1. Subject information, perturbation responses and feedforward amplitude responses.
Data for individual subjects in Experiment 2 (summarized in Figure 2C–I) and Experiment 3 (summarized in Figure 2K).
elife-40145-fig2-data1.xlsx (15KB, xlsx)
DOI: 10.7554/eLife.40145.012

Figure 2.

Figure 2—figure supplement 1. Individual subject power spectra of cursor velocity with perturbations.

Figure 2—figure supplement 1.

(A) Power spectra of cursor angular velocity for individual subjects with 1–5 Hz perturbations and no feedback delay. The average over subjects is shown in Figure 2C. (B) Power spectra of cursor angular velocity for individual subjects with 1–5 Hz perturbations and 200 ms feedback delay. The average over subjects is shown in Figure 2D.
Figure 2—figure supplement 2. Individual subject power spectra of force velocity with perturbations.

Figure 2—figure supplement 2.

(A) Power spectra of force angular velocity for individual subjects with 1–5 Hz perturbations and no feedback delay. The average over subjects is shown in Figure 2F. (B) Power spectra of force angular velocity for individual subjects with 1–5 Hz perturbations and 200 ms feedback delay. The average over subjects is shown in Figure 2G.
Figure 2—figure supplement 3. Feedforward task.

Figure 2—figure supplement 3.

(A) Schematic of the feedforward isometric task. Subjects generated sinusoidal forces within a set range, at a frequency indicated by an auditory cue. (B–D) Performance of an example subject for frequencies between 1–5 Hz. (E) Power spectrum of force for individual subjects. The average over all subjects is shown in Figure 2J.