Extended Data Fig. 3: Stimulus–neural association is robust to different analytical procedures in the current study.

As the stimulus on each trial would elicit a pattern of neural activity, the neural similarity across trials can be accessed either at the trial level or at the item level averaged across trials (the left panel in the figure). It is known that this analytical choice would lead to different magnitudes of the stimulus–neural correlation, as the correlation metric tends to scale with the number of data points included in its calculation⁸⁹. It is therefore improper to directly interpret the magnitude of the raw correlation values or their Fisher’s transformation values (the middle panel in the figure) as effect size estimates. By standardizing these correlation estimates at each time point against data with shuffled trial labels (see Extended Data Fig. 2a for an example), we can obtain a proper effect size estimate of the stimulus–neural association strength given the across-trial variability within each participant at each time point (the right panel in the figure). This approach also does not scale or alter the distribution of the data, providing better estimates of standardized scores as compared with other procedures (for example, standardization across time points). Critically, regardless of the method chosen for the analysis (as also seen in Extended Data Fig. 4), the multivariate neural signals recorded from the MTL are clearly correlated with the cued item in the STM task, within the 500 ms following the offset of the task stimuli (that is, ~ 500–1,000 ms following stimulus onset). Noticeably, neural separation scores in the MTL for the cued color relative to other colors within this period across different adjacent time points are also robustly correlated with participants’ subsequent recall performance (Extended Data Fig. 2c). Combined, these results suggest that our findings during MTL recordings are robust to the different analytical procedures or parameter choices. Shaded areas in the current figure represent the s.e.m. across participants. Significant timepoints after cluster-based correction for multiple comparisons at the 0.05 level are marked in red (cued versus shuffled items) and green (cued versus both shuffled and uncued items) depending on the contrast performed.