Feature-specific neural reactivation during episodic memory

• Published in: Nature communications Vol. 11; no. 1; p. 1945
• Main Authors: Bone, Michael B, Ahmad, Fahad, Buchsbaum, Bradley R
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 23.04.2020; Nature Publishing Group UK; Nature Portfolio
• Subjects: Activation; Adult; Brain Mapping; Cortex (frontal); Decomposition reactions; Feature recognition; Female; Functional magnetic resonance imaging; Humans; Magnetic Resonance Imaging; Male; Mapping; Memory; Memory, Episodic; Neocortex - diagnostic imaging; Neocortex - physiology; Neural networks; Neural Pathways - physiology; Object recognition; Pattern Recognition, Visual - physiology; Photic Stimulation; Semantics; Target recognition; Visual cortex; Visual Perception - physiology; Visual tasks; Young Adult
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-15763-2

We present a multi-voxel analytical approach, feature-specific informational connectivity (FSIC), that leverages hierarchical representations from a neural network to decode neural reactivation in fMRI data collected while participants performed an episodic visual recall task. We show that neural reactivation associated with low-level (e.g. edges), high-level (e.g. facial features), and semantic (e.g. "terrier") features occur throughout the dorsal and ventral visual streams and extend into the frontal cortex. Moreover, we show that reactivation of both low- and high-level features correlate with the vividness of the memory, whereas only reactivation of low-level features correlates with recognition accuracy when the lure and target images are semantically similar. In addition to demonstrating the utility of FSIC for mapping feature-specific reactivation, these findings resolve the contributions of low- and high-level features to the vividness of visual memories and challenge a strict interpretation the posterior-to-anterior visual hierarchy.