Figure 3.

Effects of 45 min versus 15 min fear extinction training on the percentage of time spent in slow-wave sleep. These effects were observed during the 6 h sleep—wake recording period that immediately followed fear extinction training. Note the significant increase in slow-wave sleep during the first 2 h of sleep—wake recording in rats that received 45 min of fear extinction training (Ext, n = 8; Failed-ext, n = 6), and the significant decrease in slow-wave sleep during the same time period in rats that received only 15 min of fear extinction training (No-ext, n = 8). Error bars represent SEM; **p < 0.01, ***p < 0.001.