Figure 5.

Neurons acquire differential responses to valence during both acquisition and extinction. A, Acquisition neurons had selective tone responses (each row is one neuron, average response over trials ±SEM in shaded color) in the acquisition when compared with habituation (columns), and had either aversive-selectivity (top row), pleasant- selectivity (middle row), or generalizing across valence (bottom row). B, Similarly for extinction neurons. See Results, Different subpopulations selectively signal acquisition and extinction, for definition and statistics used to identify and categorize neurons. C, D, Proportions of acquisition (C) and extinction (D) cells for the three types of responses (±95% binomial confidence intervals). There were significantly more neurons than chance level in all groups (p < 0.05, binomial tests). There were significantly more aversive-selective neurons during acquisition, compared with all other groups (p < 0.01, ANOVA).