◐Partially reproducedResults, Heading cells exhibit similar preferred directions during rotation of the animal or the environment; Figure 2E, Fverifier disagreed at firstrests on an assumption
Matched ROIs have on average the same preferred heading relative to the wall pattern whether the head is rotated in a fixed chamber or the chamber is rotated around a fixed head (V-test against 0 degrees, V = 14.1, p = 2.5e-4), though not all cells keep their preference.
matched ROIs on average have the same heading preference with respect to wall pattern across conditions ... (V32 = 14.1, p = 2.5 × 10−4, V-test for nonuniformity against 0°
Results, Heading cells exhibit similar preferred directions during rotation of the animal or the environment; Figure 2E, F
What the paper reports
- V-test for nonuniformity against 0 degrees, V32 = 14.1, p = 2.5 × 10⁻⁴ (n = 32 (the subscript of V, read as the number of matched cells), 5 recordings over 4 mice)
The criterion's test passes only under assumptions. Cells selective in both conditions, peak preference, chamber-rotation (CR) heading mirrored, the 5 pairs whose stored headings run in opposite directions, give V = 34.6, n = 228, p = 5.9e-04 ('fit' preference V = 36.0, p = 3.8e-04; cells selective in CR V = 47.7, p = 7.3e-05). 4 of 24 readings give p < 0.05 with V > 0. With all 7 pairs none does, and with the headings as stored every V is negative. Neither the mirroring nor the choice of 5 pairs can be checked against the data. The V is not the paper's 14.1 (n = 32), and no reading has n near 32. Matched ROIs do not keep their preference better than random pairs: pairing ROIs at random over the 5 pairs gives a larger V (mean 46.2, 95th percentile 57.6), and within every pair the real V lies inside its own random-pairing null (share of 1000 random pairings at or above it 0.222 to 0.998; SKKS116, the one pair with a large V, 58.9 against a null mean of 56.8). Head-rotation files have more selective cells (52 to 83% against 8 to 65%) and more activity (0.095 to 3.19 spikes/s against 0.063 to 0.114) than their CR partners, so heading-locked artefacts of derotation are not excluded. A 6-frame clock offset would move preferences by 4 to 8 degrees (head rotation) or 12 degrees (six of the CR files); the clock check of single_cue.ipynb peaks at -6 frames in one of four files, so the timing is not established. The seventh CR file, 210526 SKKS112-PlatformRotation-002, barely rotates (median step 0.12 degree per frame against about 2 in the others; 10 trials against 26).
How the test differed from the paper’s method
- Assumption. The stored headings of 5 of the 7 pairs run in opposite directions in the two conditions, while the paper says the cue moves across the visual field in the same direction in both (Figure 2B legend), so the CR heading is mirrored to put both in the frame of the wall pattern. The files do not say how either heading is defined.
- Assumption. The dataset holds 7 pairs over 5 mice; the paper reports 5 over 4, which matches the 5 opposite-direction pairs. Both sets are shown.
- Cells selected with the centred fit of fig1g-rotation-heading-fraction; spikes without neuropil correction.