Fig. 1: Neuropixels implantation procedure and analysis.

a, Picture of Neuropixels insertion with robotic guidance. b, The probe entry site for p8 warped onto the canonical brain, illustrated with a crimson dot within the hippocampus (shown in yellow). Code from ref. ⁵¹ used to generate the image. c, In one patient (p8), we extracted the probe along with the tissue. Shown is a 3D reconstruction (micro-computed tomography) identifying the probe within resected hippocampal tissue (left) with coronal slice identifying the probe penetrating the hippocampus (right). The superior globule is fibrin glue adhering to the ependymal lining. d, Axial (left) and coronal (right) sections of T1 magnetic resonance imaging for p8. The crimson dot indicates the probe entry site, and the arrows show the trajectory of the probe. e, Example waveforms from units collected in our recording. The thin lines are individual spikes (n values are listed in the panel); the thick line represents the median. f, Photograph of the hippocampal brain tissue with the inserted Neuropixels probe during intraoperative recording (middle right), with the anatomical orientation indicated below. g, Example waveforms from all units (n = 127) within a single hippocampal recording (p5). Each unit is represented by the waveforms at the three channels with greatest magnitude. The x axis refers to each of the four columns in the columnar arrangement of sensors. The y axis shows the position along the electrode shank. h, The analysis pipeline; we transcribed individual words with precise temporal alignment. Vertical lines are spike times, and magenta lines show the smoothed firing rates. i, Drift maps illustrating the low drift rates and high stability of Neuropixels recordings in human hippocampus. The x axis shows the time across the session. The y axis shows the depth along the electrode shank. The points (black marks) indicate individual spikes. The banding pattern reflects degree of motion before (top) and after (bottom) motion correction. For c, scale bars, 1,000 μm (left) and 300 μm (right).