Trial timing and pattern-information analyses of fMRI data.

摘要: Pattern-information approaches to fMRI data analysis are becoming increasingly popular but few studies date have investigated experimental design optimization for these analyses. Here, we tested several designs that varied in the number of trials and trial timing within fixed duration scans while participants encoded images animals tools. Trial conditions with onset-to-onset ranged from slow 12-s two repetitions each item quick 6-s four per item. We also a jittered version 4-8s trials. assessed effect on three dependent measures: category-level (animals vs. tools) decoding accuracy using multivoxel pattern analysis, item-level (e.g., cat dog lion) information estimates similarity memory effects comparing scores across individual items subsequently remembered forgotten. For single estimates, category was equal all were better detected timing. When modeling events an item-by-item basis given item, larger quick, regularly spaced provided advantage over fewer comparable conditions. Jittered non-jittered versions did not differ significantly any analysis. These results will help inform choices future planning employ pattern-information analyses demonstrate guidelines developed univariate necessarily optimal condition-rich designs.