Fig. 5: Cortical responses to targets predict behavioral performance and exhibit contrast adaptation.

a Schematic of chronic recordings during behavior. Tetrode drive images are adapted from ref. ⁸⁵. b Spike raster from a neuron recorded during the task with average PSTHs. Inset: area under the ROC curve (AUC) for each level ±bootstrapped 95% CI. c Neurograms of populations of simultaneously recorded neurons in low (left) and high contrast (right) sessions. Color bars indicate the difference in firing rate between the noise-only condition and each target level. The arrow indicates the cell in b. d Upper left: schematic for estimating the population coding direction (CD). Lower right: probability distributions of CD projections for noise-only trials (gray) and the highest-level target trials (blue). The vertical red line indicates the criterion for the decoder. e Neurometric performance and behavioral performance in representative low contrast (top) and high contrast (bottom) sessions. Dark dots are decoder performance, while light dots indicate behavioral performance, overlaid by logistic function fits. The arrow indicates the decoder performance for the distributions in d. f Average psychometric and neurometric performance ±SEM over sessions. Formatting as in e. g Behavioral performance as a function of neurometric performance for n = 102 sessions. Each point is performance at a single target level in a single session. Point color indicates contrast, while point size indicates target level. Dots joined by gray lines were collected in the same session. Inset: Same data as in g, with the effect of target level regressed out (!L). The black line indicates the model fit and 95% CI. h Behavioral performance as a function of neural performance split by target levels. Text indicates the correlation coefficient and its significance value. i Top: the linear model used to predict behavior. Bottom: model coefficients ±standard error for target level (L), contrast (C), neurometric performance (N) terms, and the interaction between the latter two terms (C*N). Asterisks indicate significant predictors (n = 102 sessions). j Neurometric thresholds ±SEM for sessions in low (n = 82) and high contrast (n = 35). Asterisks indicate significant two-way rank-sum test (p = 1.34e−6). k Same as j, but for neurometric slopes (two-way rank-sum test: p = 0.029). l Left: Neurometric performance ±SEM as a function of target delay over sessions (n = 87). Formatting and statistical tests are the same as Fig. 3f. Right: Adaptation time constants ±SEM fit to the neurometric response from n = 12 mice. Asterisk indicates a significant two-way sign-rank test (p = 0.016). Source data are provided as a Source Data file.