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. Author manuscript; available in PMC: 2021 Dec 22.
Published in final edited form as: Neuron. 2021 Jul 22;109(17):2767–2780.e5. doi: 10.1016/j.neuron.2021.06.020

Figure 1. Experimental design, intracranial recordings, and ripple detection.

Figure 1.

(A) Intracranial electrodes were implanted in the hippocampus and cortex as part of a neurosurgical treatment for medically intractable epilepsy.

(B and C) Participants were instructed to make true/false judgments about a series of visually presented statements, requiring either autobiographical memory (autobio), arithmetic processing, or semantic knowledge (in a subgroup of 11 subjects).

(D) Hippocampal electrodes in 1 example patient. Red circles indicate recording sites where ripples were detected. To see the map of hippocampal coverage across all subjects, see (I).

(E) Schematic diagram of a typical depth iEEG electrode used in our study (see also Table S3).

(F) Example of hippocampal ripples as they appear in a CA1 recording site (see black arrow in D). Orange triangles mark ripple events that met the detection criteria (see STAR Methods).

(G and H) Mean peri-ripple field potential and wavelet spectrogram for the same CA1 site described in (F), showing the typical spectrotemporal signature of human hippocampal ripples (n = 521 ripples, peak frequency: 94 ± 1.71 Hz).

(I) Overview of ripple rate computed over the entire experiment, for each hippocampal site included in our analysis (112 sites from 20 patients). Inset: distribution of ripple rates across electrodes.