Figure 4.

The fidelity of hippocampal attentional states during encoding of novel information predicts goal-directed memory. (A) While undergoing high-resolution fMRI, individuals performed the “art gallery” task used in [50] and depicted in Figure 3. This part of the experiment (Phase 1) was used to extract activity patterns in the hippocampus related to attending to paintings and attending to room layouts — i.e., attentional state “templates” for each task. Participants then encoded a novel set of 3D-rendered rooms in Phase 2, attending to art in one block and room layouts in the other. Finally, in Phase 3, they were taken out of the scanner and tested on their memory for the goal-relevant aspect of images from Phase 2: paintings from the art encoding task and room layouts from the room encoding task. (B) To investigate how hippocampal attentional states related to memory formation, the activity pattern for each Phase 2 encoding trial was correlated with the task-relevant and task-irrelevant attentional state templates, defined from Phase 1. For example, the activity pattern for an art encoding trial would be correlated with the art state template (task-relevant) and the room state template (task-irrelevant). The difference between these pattern similarity correlations provided a measure of the extent to which the hippocampus was in the correct attentional state during encoding. (C) In CA2/CA3/DG (and in the hippocampus treated as a single region of interest), activity patterns more closely resembled the task-relevant vs. task-irrelevant attentional state during successful vs. unsuccessful encoding. * p < .05. Figure adapted from [56].