✕Not reproducedResults, Correlated activity in GPi-VLa cell pairs is rare and unbiased, paragraph 1; Fig 4A-F; Table 2
Short-time-scale spike-to-spike correlations between simultaneously recorded GPi and VLa units are rare (3.5% of 427 pairs over whole recordings, 2.2% of 183 at rest, 5.2% of 172 during movement) and their peaks are not larger than those of jittered controls (p = 0.975, 0.675 and 0.998).
only 3.5% of the CCFs showed any statistically significant modulation (15 of 427 cell pairs; ... the overall distribution of the peak absolute correlation values was not greater than the distribution of control peak absolute correlations
Results, Correlated activity in GPi-VLa cell pairs is rare and unbiased, paragraph 1; Fig 4A-F; Table 2
What the paper reports
- peak absolute correlations against jittered controls, whole recordings: one-sided permutation test, p = 0.975 (n = 427 pairs)
- peak absolute correlations against jittered controls, rest: one-sided permutation test, p = 0.675 (n = 183 pairs)
- peak absolute correlations against jittered controls, movement: one-sided permutation test, p = 0.998 (n = 172 pairs)
By the KS permutation test the peak CCFs exceed those of jittered controls over whole recordings (338 pairs, p = 0.003) and during movement (306 pairs, p = 0.045), not at rest (298 pairs, p = 0.705). Significant pairs are 5.6%, 3.4% and 6.5%, none above 5% by a binomial test, and mostly positive (15 of 19 whole, 15 of 20 movement). The shift is small (median peak 0.042 against a control median of 0.038). The part of the statement that correlations are rare holds; the part that peaks are not larger than controls does not. Keeping only pairs with an approximate c0 of at most 0.3 leaves 332, 121 and 172 pairs (paper 427, 183 and 172) with KS p = 0.003, 0.333 and 0.025; one file per pair of presumed neurons gives 0.003, 0.627 and 0.037. The significant peaks fall at lags spread over 0 to 10 ms, and GPi and VLa spikes share a sample as often as independent trains would (11,376 against 11,435 expected), so shared artefacts do not explain the excess. Spike times are at the sample resolution (24414.0625 Hz) in every file. With the paper's records, paired when a GPi and a VLa record share a file (329, 298 and 301 pairs), the peaks exceed the controls over whole recordings (p = 0.005) and at rest (p = 0.033), not during movement (p = 0.203), so the outcome would be the same. Neither pair set matches the paper's 427 whole-recording pairs (338 on the dandiset rule, 329 on the paper's records); this attempt did not find out how the paper counted its pairs.
How the test differed from the paper’s method
- The paper's exclusion of pairs with a minimum detectable correlation c0 above 0.3 is not applied in the main test, which the criterion fixed before the analysis; the paper's simulation is not in its deposit. It is shown as a variant, with c0 approximated by a simulation on the CCF counts (independent Poisson counts at the pair's expected count, plus an injected peak).
- Only VLa spikes are jittered; the Methods do not say which train.