Across 18.5% (2,087/11,264) of hippocampal-LS cell pairs examined, spike trains of hippocampal neurons reliably predicted the firing of action potentials in LS neurons ... the median optimal timescale for peer prediction was 25 ms (Figure 5F)
Results, paragraph 7; Figure 5D to 5F
Changed from blocked in revision, at the verifier's request, by testing a random sample of pairs. Of 670 sampled pairs (of 70,898 hippocampal-LS pairs active in the same condition, counted per condition; 20,979 pairs of active units recorded together, against the paper's 11,264), 35 form an assembly of strength at least 4 (5.2%, 95% interval 3.7% to 7.2%), against 18.5%, and the median best window of the assemblies is 20 ms, against 25. Both are outside the criterion. The real gain beats all ten shuffles in 35.4% of pairs; this has no 1 in 11 reference, as the window is chosen on the real fit and the shuffles run only at that window. With thresholds of 1.5, 2 and 8 the fractions are 19.4%, 12.7% and 1.8%. Per rat 0% (DT7, 5 pairs) to 10.2% (DT5). With the LS unit's rate map at the current position added as a covariate, 5.5% (95% interval 3.9% to 7.5%), so the linear coding of position does not account for the low fraction.
How the test differed from the paper’s method
- A random 1% of the pairs, as all pairs need about 12 process-hours at about 0.6 s per pair measured in this run (1.2 s in the previous run).
- The bin size (1 ms), the Gaussian kernel, the window grid (13 windows from 1 to 150 ms) and the covariate coding are choices made here; the Methods do not give them and the paper's assembly code is not public. Shuffles are run at the best window only.
- Pairs are counted once per condition in which both units are active, as the Methods imply (one strength per pair and block of trials).