Article Figures & Data
Figures
- Figure 1.
Behavioral performance measures. Mean across subjects and sessions for accuracy (A), RT (B), and RT variability (C) in each of the four tasks. Error bars: SEM across subjects. Asterisks: significant differences across experiments (post hoc Tukey’s tests,
). One asterisk: significant differences between CB experiment and choice reaction time (CRT) or GNG experiments. Two asterisks: significant differences between 2B experiment and all other experiments. CB, Checkerboard; GNG, go-no-go; 2B, 2-back. - Figure 2.
Temporal and spatial dynamics of trial-by-trial neural variability. Each time course represents the changes in relative trial-by-trial variability (percentage-change units relative to the prestimulus period, mean across the four selected electrodes) during the first (black) or second (gray) experimental session, which were separated by one year. Each panel displays the results of a different experiment. Gray background: 150- to 400-ms poststimulus period with sustained variability quenching that was selected for further analyses. Insets, Topographic maps of variability quenching magnitudes during the 150- to 400-ms window, demonstrating that quenching was strongest in occipital electrodes across all four experiments.
- Figure 3.
Individual neural variability magnitudes were consistent across experimental sessions separated by one year. Scatter plots present the magnitudes of variability quenching (A), prestimulus variability (B), and poststimulus variability (C) in individual subjects during the first and second experimental sessions for each of the four experiments. The unity line is drawn for reference in each panel. Each point represents a single subject. Asterisks: significant correlation as assessed by a randomization test (
). Pearson’s correlation coefficients and p values are noted in each panel. - Figure 4.
Individual variability quenching magnitudes were consistent across experiments. Scatter plots demonstrate the relationship between variability quenching magnitudes in each pair of experiments. Each dot represents a single subject. The linear fit is drawn for reference in each panel. Asterisks: significant correlation as assessed by a randomization test (
). Pearson’s correlation coefficients and p values are noted in each panel. - Figure 5.
Scalp maps representing the correlation between measures of neural variability (quenching, prestimulus, or poststimulus) and behavioral measures: accuracy (A) or RT (B). Color bar: magnitude of Pearson’s correlation coefficients.
- Figure 6.
Temporal dynamics of the CV in percentage change units relative to prestimulus period. Each panel presents results from a single experiment in the first (black) and second (gray) experimental sessions. Gray background: time window (150-400 ms) of sustained variability quenching that was selected for the previous analyses.
Tables
- Table 1.
Individual magnitudes of prestimulus (top row) and poststimulus (bottom row) neural variability were strongly correlated across experiments
CB-CRT CB-GNG CB-2B CRT-GNG CRT-2B GNG-2B Prestimulus r = 0.86
p = 0.5*10−7r = 0.93
p = 0.8*10−10r = 0.86
p = 0.8*10−7r = 0.96
p = 0.3*10−13r = 0.89
p = 0.6*10−8r = 0.93
p = 0.8*10−10Poststimulus r = 0.9
p = 0.1*10−8r = 0.9
p = 0.2*10−8r = 0.89
p = 0.4*10−8r = 0.95
p = 0.1*10−11r = 0.9
p = 0.1*10−8r = 0.94
p = 0.1*10−10Pearson’s correlation coefficients and p values are noted for each pair of experiments. CB, Checkerboard; CRT, choice reaction time; GNG, go-no-go; 2B, 2-back.
Accuracy Mean RT RT variability Quench Pre Post Quench Pre Post Quench Pre Post CB r = 0.17
p=0.43r = −0.21
p = 0.3r = −0.12
p = 0.57r = 0.12
p = 0.55r = −0.05
p = 0.8r = 0
p = 0.98r = −0.02
p = 0.92r = −0.06
p = 0.77r = −0.13
p = 0.54CRT r = 0.13
p = 0.55r = −0.05
p = 0.82r = 0.07
p = 0.75r = 0.14
p = 0.5r = −0.05
p = 0.8r = 0.17
p = 0.4r = −0.1
p = 0.63r = 0.2
p = 0.35r = 0.22
p = 0.29GNG r = −0.03
p = 0.88r = −0.15
p = 0.48r = −0.18
p = 0.38r = 0.08
p = 0.7r = 0.04
p = 0.86r = 0.17
p = 0.41r = 0.02
p = 0.93r = 0.14
p = 0.5r = 0.29
p = 0.162B r = −0.13
p = 0.54r = 0.13
p = 0.53r = 0.21
p = 0.32r = −0.2
p = 0.35r = 0.1
p = 0.62r = 0
p = 0.96r = −0.36
p = 0.09r = 0.22
p = 0.3r = 0
p = 0.99Pearson’s correlation coefficients and p values for each behavioral (accuracy, mean RT, or RT variability) and each variability (quenching, prestimulus, or poststimulus) measure. CB, Checkerboard; CRT, choice reaction time; GNG, go-no-go; 2B, 2-back.
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