Interpretation of correlated neural variability from models of feed-forward and recurrent circuits
Fig 8
Effect of correlations on stimulus discrimination.
A: Signal-to-noise ratio S, dots correspond to pairs of stimuli. Value from observed covariance matrix versus value based on shuffled trials, for different populations (different colors) in the same animal. B: Same data, distribution of S(shuffled)/S(original). Broad distribution, but mean value greater than one for all populations (tics) indicates that shuffling increases information on average. C: Distribution of cosine of angle between diagonal and average-response difference, across stimulus pairs for different neural populations. Large cosines/small angles are most frequent. D: Scatter plot of effect of correlations on discrimination. Small dots correspond to stimulus pairs. Connected large dots indicate average value in a bin centered at the corresponding location on the x-axes. E: The distribution of mean values across all measured populations shows that correlations are on average unfavorable, for almost all populations. F: Average effect of noise correlations is stronger for larger signal correlations.