Fig. 4.

Nlgn1^−/− mice show reduced motivation to overcome response effort for rewards. a Fixed ratio task required a fixed number of nose-pokes (e.g., 5 responses, FR5) for a single reward. Responses to FR1, 5, 20, and 40 were measured. b Total number of responses averaged over three sessions per ratio requirement. Bars indicate 1st, 2nd (median), and 3rd quartiles. c Nlgn1^−/− mice made fewer responses in the higher ratio requirements (effect of genotype < 0), quantile regression (median), **p < 0.005, values represent estimated effect of genotype on response counts ± 95% CI. d Post-reinforcement pause (time to the first response after consuming a reward, seconds) averaged over three sessions per ratio requirement. e Median inter-response interval (time spent per response after an animal made the first response of a trial, seconds per response), averaged across three sessions per ratio requirement. See Additional file 1: Fig. S11 for response-by-response breakdown of raw inter-response intervals. f Nlgn1^−/− mice also made fewer responses for water rewards on fixed ratio 20 (FR20), linear regression, **p < 0.005 values represent means ± SEM. g Number of responses made for milk rewards positively correlated with number of responses made for water rewards on FR20 for both WT and Nlgn1^−/− mice, linear regression, **p < 0.005