Graded contribution of hippocampus to multifeature binding across temporal delay.

It is well accepted that all the elements of an episode are combined together by the hippocampus to form an episodic representation. In this study, we further investigated whether the activation pattern of the hippocampus during multifeatural episodic encoding with temporal discontinuities varies with recollective detail in a graded way. Specifically, in the present functional magnetic resonance imaging study, we manipulated two associative features, color and size, and presented the features and the item sequentially. Right hippocampal activation increased with the number of features successfully bound to the item, supporting a graded role of hippocampal activation in bridging temporal discontinuities for integrating multiple episodic features.