Schedule of Events | Search Abstracts | Invited Symposia | Symposia | Poster Sessions | Data Blitz

A Spectral T+A-G+ of Memory

Poster Session D - Monday, March 9, 2026, 8:00 – 10:00 am PDT, Fairview/Kitsilano Ballroom

Adam Broitman¹ (), Michael Kahana²; ¹University of Pennsylvania

Spectral analysis of invasive and non-invasive electroencephalographic (EEG) recordings have revealed consistent frequency-specific power modulations that predict successful episodic memory performance. Across a broad range of encoding and retrieval tasks, mnemonic success is marked by a pattern we refer to as spectral T+A-G+, characterized by increased low-theta power (~3-5 Hz; T+), decreased alpha power (~8-10 Hz; A-), and increased gamma power (30+ Hz; G+). Here, we synthesize evidence for T+A-G+ from scalp and intracranial EEG experiments, evaluating its robustness across tasks and contrasts. We review mechanistic accounts linking theta oscillations to hippocampo-cortical coordination, alpha suppression to reduced inhibition, and gamma activity to local computation supporting neural representations. Finally, we consider whether T+A-G+ reflects the activation of memory-specific processes, as opposed to a task-general marker of cognitive effort and engagement. Converging evidence suggests that, although each component of T+A-G+ is involved in task-general cognitive processes, their combined expression emerges most reliably during memory tasks. This supports the view that T+A-G+ represents the joint activation of neurocognitive processes which are critical for episodic memory.

Topic Area: LONG-TERM MEMORY: Episodic