Article Figures & Data
Figures
- Figure 1.
Task design and behavioral results of Experiments 1 and 2. A, The trial structure of the AB task used in Experiments 1 and 2. Each trial consisted of a stream of rapidly presented letters in which predefined target letters had to be detected and then reported at the end of the stream. The first target (T1: a green G or H) always appeared at the fifth position. The second target (T2: D or K) was presented at varying SOAs (lags) after the first one and was marked by placeholders. The identity of T1 predicted which of the T2 targets was most likely to appear, thereby introducing validly and invalidly predicted T2 targets. On 20% of the trials no second target was presented and a random distractor letter was presented instead. B, Percentage correct T2 target detection at each of the T1–T2 lags for valid expectations, invalid expectations, and T2-absent trials in Experiment 1. Validly predicted T2s were significantly more often perceived than invalidly predicted T2s. C, Percentage of T2 target detection at each of the T1–T2 lags after a valid or invalid expectation or on a T2-absent trial for Experiment 2. Again, validly predicted T2s were more often perceived, in particular at short lags. Error bars represent SEM.
- Figure 2.
ERP effects related to T2 prediction validity. A, Topographic maps of the difference between validly and invalidly predicted T2s over time (0 corresponds to T2 onset). Cluster-based permutation tests were used to isolate the significant events, while correcting for multiple comparisons across time and (electrode) space. On each head map, channels with a significant effect for ≥50% of its time window are highlighted. B, The average ERP time course of the 10 channels shown on the head map on the left, shown separately for each validity condition. The significant time-window is marked by a black line above the x-axis. Invalidly predicted T2s were associated with greater frontocentral negativity than validly predicted T2s. C, Bar graphs showing the average amplitude of the four conditions (visibility × prediction) for the significant neural event shown in B. In all plots error bars represent SEM.
- Figure 3.
ERP effects related to T2 visibility analyses. A, Topographic maps showing the difference between seen and missed T2s over time (0 corresponds to T2 onset). Cluster-based permutation tests were used to isolate the significant events while correcting for multiple comparisons across time and (electrode) space. On each head map, channels showing a significant difference for ≥50% of its time window are highlighted. Three events were isolated based on the permutation tests. B, D, F, For each of the events individually, the average ERP time course of the 10 channels shown on the head map on the left, separately for T2-seen and T2-missed conditions is shown. The significant time-window is marked by a black line above the x-axis. C, E, G, Bar graphs showing the average amplitude of the four conditions (visibility × prediction) for the significant neural events shown in B, D, F. In all plots error bars represent SEM.
- Figure 4.
Task design and behavioral results of Experiment 3. A, Trial structure of the task used in Experiment 3. T1 visibility was staircased at ∼75% correct by manipulating its duration (on 20% of trials no T1 was presented). B, Percentage of correct T2 target detection at each of the T1–T2 lags after a valid or invalid expectation and on a T2-absent trials for trials where T1 was correctly reported (T1 seen). As in Experiments 1 and 2, when T1 was seen, validly predicted T2s were more often detected than invalidly predicted T2s. C, Solid lines show percentage of T2 target detection at each of the T1–T2 lags after a valid or invalid expectation and on T2-absent trials for trials where T1 was presented but missed. In contrast to T1-seen trials (B), when T1 was not seen, validity did not enhance T2 detection. However, a missed T1 still triggered a significant AB, compared with trials on which no T1 was presented (dotted line). Error bars represent SEM.
