Key Points:
- We provide a dataset obtained from iEEG
- A total of 5 participants completed the tasks that involved an audio-visual spatial memory task with memory associated sounds played during sleep.
- The data is fully preprocessed and ready for analysis in three unique frequency bands; Theta (4-8Hz), sigma (12-16Hz), and gamma (20-100Hz). We followed up by testing low gamma (20-50 Hz), mid-gamma (50-80 Hz), and high gamma (80-100 Hz) as well as a separate ripple analysis. and Research Overview:
Here, we investigated overnight memory change by measuring electrical activity in and near the hippocampus. Electroencephalographic (EEG) recordings were made in five patients from electrodes implanted to determine whether a surgical treatment could relieve their seizure disorders. One night, while each patient slept in a hospital monitoring room, we recorded electrophysiological responses to 10-20 specific sounds that were presented very quietly, to avoid arousal. Half of the sounds had been associated with objects and their precise spatial locations that patients learned before sleep. After sleep, we found systematic improvements in spatial recall, replicating prior results. We assume that when the sounds were presented during sleep, they reactivated and strengthened corresponding spatial memories. Notably, the sounds also elicited oscillatory intracranial EEG activity, including increases in theta, sigma, and gamma EEG bands. Gamma responses, in particular, were consistently associated with the degree of improvement in spatial memory exhibited after sleep. We thus conclude that this electrophysiological activity in the hippocampus and adjacent medial temporal cortex reflects sleep-based enhancement of memory storage.
Citation to related publication:
Creery JD, Brang D, Arndt JD, Bassard A, Towle VL, Tao JX, Wu S, Rose S, Warnke P, Issa NP, Paller KA (in press). Electrical Markers of Memory Consolidation in the Human Brain when Memories are Reactivated during Sleep. Proceedings of the National Academy of Sciences.
