Table 1 Response variability decreases with stimulus size.

From: Neuronal variability reflects probabilistic inference tuned to natural image statistics

Experiment

FF decrease

(½ RF)–(1 RF)

FF decrease

(1 RF)–(2 RF)

p Value

Mean-matched FF decrease

(size < RF)–(size > RF)

p Value

1. Natural, awake

(N = 86; Fig. 2f)

18.7%

5.7%

0.0082

25.7%

<10−5

2. Gratings, awake

(N = 19; Supplementary Fig. S4)

31.7%

9.0%

0.05

47.7%

<10−3

3. Gratings, anesthetized

(N = 229; Supplementary Fig. S4)

14.2%

7.0%

<10−3

22.6%

<10−5

  1. Rows: separate experiments, with number of neurons selected in each experiment (inclusion criteria in Methods). Columns: Column 1, experiments. Columns 2–4, changes in FF with stimulus size. Columns 5 and 6, mean-matched (see Methods) change in FF with stimulus size. In all cases, a positive change denotes a reduction in FF for larger stimuli. Column 2: change in FF (Methods, Eq. 5) from the stimulus closest to ½ of the RF size (out of all tested sizes) to the RF-sized stimulus. Column 3: change in FF from the RF-sized stimulus to the large stimulus (closest to 2 × RF size). Column 4: the p value for the second column. Column 5: FF change from stimuli smaller to larger than RF size. Sizes are selected to match the mean spike count across neurons (spike count change <3%, p > 0.05, for all experiments). Column 6: p value for column 5. The p values were computed with a one-sided paired samples t test of the null hypothesis that the difference between the two conditions had mean ≤ 0.
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