MVPA results
MVPA analyses showed that neural activity between the small and large
choice sets began to differ 128 ms after stimulus onset and persisted
until 1500 ms (p < 0.001, cluster-based correction;Fig. 4A ). Temporal generalization matrices indicated that
neural activity between the small and large choice sets during these
time periods (training time = [128,1488], testing time = [108,
1488], p < 0.001; Fig. 4B ) could be
predicted from one another. As depicted in the activation maps inFig. 4C , the posterior electrodes exhibited activation
(p < 0.001, cluster-based corrected) while the anterior
electrodes showed inhibition (p < 0.001, cluster-based
corrected) in the early stage. However, in the late stage, the posterior
electrodes were inhibited (p < 0.001, cluster-based
corrected) and the anterior electrodes were activated (p< 0.001, cluster-based corrected). No significant cluster of
electrodes was observed during the middle stage. Furthermore, the
decoding outcomes for four different choice set sizes were illustrated
in Supplemental Figure 1 . The significant time clusters between
the two adjacent choice sets (e.g., between 4 and 8) were relatively
small; however, as the number of choices that differ between them
increases, the significant time clusters become more expansive.