Fig. 3: Attention strength fluctuates at around 11 Hz.
From: Rhythmic sampling of multiple decision alternatives in the human brain
a The distribution of the z-scored attention strength, i.e., vector length. The blue line indicates the average over trials and participants, the shaded area the standard error of the mean (SEM). Vertical dashed lines indicate the stimulus onset, framing cue onset and offset, as well as the stimulus offset (from left to right). b The average normalized pupil diameter during task execution. The thick line and shaded area indicate the average and the SEM over participants. c Single trial example traces of the normalized attention strength. The depicted trials are from participant 1, session 1. d Windowed normalized amplitude (Ampl.) spectra of attention strength fluctuations over the trial. Lines indicate the participant average, shaded areas display the SEM. The lines are color-coded according to the window onset (0.5 sec. window length) with regard to the framing cue, from early (blue) to late (pink) windows. e–g Frequency-specific change of attention strength amplitude relative to baseline. The frequency-wise amplitude strength values were normalized by dividing the average amplitude during the 0.5 s prior to stimulus onset and displayed in dB. e Time-frequency resolved (TFR) distribution of the amplitude of attention strength fluctuations. Red and blue colors indicate an increase or decrease relative to baseline, respectively. The values were statistically masked at pFDR < 0.01 within each frequency. Vertical dashed lines as in (a). f Average frequency-wise amplitude change (as in e) throughout the stimulus presentation period. Thick and thin lines display the average and single participant amplitude changes (nparticipant = 20), respectively. Colored bars denote change from baseline (two-sided t test(19), pFDR < 0.05, FDR-corrected over frequencies). g Attention strength fluctuation amplitude averaged for frequencies between 7–13 Hz, relative to baseline in dB. The shaded area indicates the SEM. h Correlation of trial-averaged amplitude envelopes of the neuronal signal (compare Supplementary Fig. S2) and attention strength fluctuation displayed on the cortical surface77. The correlation was computed for the broadband as well as frequency resolved signals. The values were statistically masked at pFDR < 0.05 within each panel.
