Article Figures & Data
Figures
- Figure 1.
Leader–Follower dynamic perturbation during retention modulates two-item memory performances (experiment 1, N = 30). A, Leader–Follower dynamic perturbation paradigm. In each trial, participants were presented with two bars, and they memorized their orientations and colors. During the memory test, participants adjusted the orientation of a probe bar to match that of the memorized bar that was the same color as the probe. During the 5 s delay period, participants performed a central fixation task while two task-irrelevant flickering disks of the same color as each of the memorized bars (blue and red) were presented bilaterally, with their luminance continuously modulated by two 5 s temporal sequences, Leader or Follower sequences, respectively. The color, spatial location, and Leader–Follower conditions were counterbalanced across trials. B, The Leader temporal sequence was a 5 s white noise randomly generated per trial, and the Follower sequence was created by circular shifting the Leader sequence 200 ms rightward. Note that the two sequences were presented simultaneously rather than asynchronously. C, The Leader–Follower cross-correlation over time as a function of temporal lag, peaking at 200 ms. D, Memory performance. Grand averaged (mean + SEM) memory precision during recalling test for Leader (purple) and Follower (turquoise) conditions, with dots denoting individual participants. E, Same as D, but for normalized target probability; *p < 0.05. Extended Data Figure 1-1 shows target probability without normalization. Extended Data Figure 1-2 shows additional parameter results (nontarget and random guess probability).
- Figure 2.
Task-irrelevant Leader–Follower dynamic perturbation (experiment 2, N = 30). A, Task-irrelevant dynamic perturbation paradigm. Experiment 2 was the same as experiment 1, except that participants needed to memorize the orientations and locations (top or bottom) of the two bar stimuli regardless of their colors. During the memory test period, a location cue (top or bottom) was first presented, and based on this participants rotated the horizontal white bar to the corresponding memorized orientation. Critically, a Leader–Follower dynamic perturbation as in experiment 1 was applied during the delay period; that is, two disks of the same color as each of the memorized bars (blue and red) were presented bilaterally, with their luminance continuously modulated by a Leader or Follower sequence, respectively. B, The Leader temporal sequence was a 5 s white noise randomly generated per trial, and the Follower sequence was created by circular shifting the Leader sequence 200 ms rightward. The two luminance sequences were presented simultaneously rather than asynchronously. C, The Leader–Follower cross-correlation over time as a function of temporal lag, peaking at 200 ms. D, Memory performance. Grand averaged (mean + SEM) memory precision during recalling test for Leader (purple) and Follower (turquoise) conditions, with dots denoting individual participants. E, Same as D, but for normalized target probability. Extended Data Figure 1-1 shows target probability without normalization. Extended Data Figure 1-2 shows additional parameter results (nontarget and random guess probability).
- Figure 3.
Leader–Follower dynamic perturbation modulates three-item memory performance (experiment 3, N = 30). A, Experiment 3 paradigm. In each trial, participants were presented with three bars, and they memorized their orientations and colors. During the memory test, participants adjusted the orientation of a probe bar to match that of the memorized bar that had the same color as the probe. During the 5 s delay period, participants performed a central fixation task while three task-irrelevant flickering disks of the same color as each of the memorized bars (blue, red, green) were presented simultaneously, with their luminance continuously modulated by three 5 s temporal sequences (Leader, Follower1st, Follower2nd), respectively. The color, spatial location, and Leader–Follower conditions were counterbalanced across trials. B, The Leader temporal sequence was a 5 s white noise randomly generated per trial, and the Follower1st and Follower2nd sequences were created by circular shifting the Leader sequence 150 and 300 ms rightward, respectively. C, The Leader–Follower1st and Leader–Follower2nd cross-correlation over time as a function of temporal lag, peaking at 150 and 300 ms, respectively. D, Memory performance. Grand averaged (mean + SEM) memory precision for Leader (purple), Follower1st (turquoise), and Follower2nd (yellow) conditions. Dots denote individual participants. E, Same as D, but for normalized target probability. Extended Data Figure 1-1 shows target probability without normalization. Extended Data Figure 1-2 shows additional parameter results (nontarget and random guess probability).
- Figure 4.
Memory-irrelevant Leader–Follower dynamic perturbation (experiment 4, N = 30). A, Task-irrelevant dynamic perturbation paradigm. Experiment 4 was the same as experiment 3, except that participants needed to memorize the orientations and locations (left/middle/right) of the three bar stimuli regardless of their color features. During the memory test period, a location cue was first presented; based on this participants rotated the horizontal white bar to the corresponding memorized orientation. Critically, a Leader–Follower dynamic perturbation as in experiment 3 was applied during the delay period; that is, three disks of the same color as each of the memorized bars (blue, red, green) were presented simultaneously, with their luminance continuously modulated by the Leader, Follower1st, or Follower2nd sequence, respectively. B, The Leader temporal sequence was a 5 s white noise randomly generated per trial, and the Follower1st and Follower2nd sequences were created by circular shifting the Leader sequence 150 and 300 ms rightward, respectively. C, The Leader–Follower1st and Leader–Follower2nd cross-correlation over time as a function of temporal lag, peaking at 150 and 300 ms, respectively. D, Memory performance. Grand averaged (mean + SEM) memory precision for Leader (purple), Follower1st (turquoise), and Follower2nd (yellow) conditions. Dots denote individual participants. E, Same as D, but for normalized target probability. Extended Data Figure 1-1 shows target probability without normalization. Extended Data Figure 1-2 shows additional parameter results (nontarget and randomly guess probability).
Extended Data
Figure 1-1
A, Target probability for the Leader (purple) and Follower (turquoise) conditions, with dots denoting individual subjects in experiment 1. B–D, Same as A, but for experiments 2–4. Correction for multiple comparisons was applied to experiments 3 and 4. Download Figure 1-1, TIF file.
Figure 1-2
A, Left, Nontarget probability for the Leader (purple) and Follower (turquoise) conditions, with dots denoting individual subjects in experiment 1. Right, Random guess probability in experiment 1. B–D, Same as A, but for experiments 2–4. Correction for multiple comparisons was applied to experiments 3 and 4. Download Figure 1-2, TIF file.
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