Extended Data Fig. 5: Spike clusters of object-vector cells with two discrete firing fields.
Separation of spikes from object-vector cells with two firing fields from spikes of other simultaneously recorded MEC cells. a, Examples of cell separation in 2D projections of multidimensional cluster diagrams. First and third columns, colour-coded rate maps showing two distinct object-vector cells, with mouse and cell ID numbers (top) and peak rates (bottom) indicated. Second and fourth columns, scatter plots showing relationship between energy (square of signal) for spikes recorded from two selected electrodes of a tetrode in the recording that contains the object-vector cell in the rate map to the left. The electrode numbers in each pair are indicated on axis labels. Each dot represents one sampled signal. Clusters are likely to correspond to spikes that originate from the same cell. The cluster giving rise to the rate map to the left of each scatter plot is shown in black; remaining signals in grey. L-ratio and isolation distance31 for cluster in black are indicated above the scatter plot. Note clear separation of the object-vector cell from other spikes, which suggests that it is unlikely that second fields reflected contamination of spikes from other cells. b, Distribution of L-ratio and isolation distance for all object-vector cells with one field (dark blue boxes; n = 102 cells; median L-ratio 0.06 (25th–75th percentiles 0.02–0.19); median isolation distance 31.2 (18.0–49.7)), and all with two or three fields (light grey boxes; n = 60 cells; median L-ratio 0.06 (0.02–0.14); median isolation distance 31.7 (21.4–49.2)). Black line between box edges indicates median, box edges indicate 25th and 75th percentiles, whiskers extend to the most extreme point that lies within 1.5 × IQR, and data points larger than 1.5 × IQR are considered outliers (red crosses).
