Figure 2.

Decoding the content of episodic retrieval from medial temporal lobe activity patterns. (A) Selected frames from one of three movie clips viewed by participants prior to scanning. During each trial of the scanning session, participants closed their eyes and attempted to recall one of the three clips as vividly as possible. (B) Illustration of the spherical searchlight analysis approach. High-resolution fMRI data were collected from the MTL, and classification analyses were run on the data from small spherical cliques of voxels to evaluate the accuracy with which local activity patterns could be used to decode which episode was recalled on each trial. (C) Frequency heat maps for the left and right hippocampi illustrating the number of participants (out of 10) for whom searchlights centered at each voxel showed above-chance mnemonic decoding performance. High across-participant consistency was observed in bilateral anterior and right posterior hippocampus. (D) Comparison of classification performance within the hippocampus (HC), entorhinal cortex (ERC) and parahippocampal gyrus (PHG) revealed above-chance (dashed line: 33%) classification in all three ROIs, with decoding accuracy being significantly higher within the HC. Adapted from Chadwick et al. (2010) and Hassibis et al. (2009).