Figure 4

Inter-individual differences in impulsivity measured in the delay-discounting task: A: distribution of individual scores of each rat (mean percentage of choice for the large reward after 5 to 30 min delays) and selection of rats with high choice for large reward (HIGH_CHX, scores > 75%) low choice for large reward (LOW_CHX, scores < 55%) and intermediate rats (INT_CHX). B: Percentage choice of the large reinforcement of the three groups according to the length of the delay before obtaining it: LOW_CHX had no preference for any lever at delays 5 to 15 min and then shifted their preference for the immediate reward, whereas HIGH_CHX preferred the largest reward whatever the delay. Comparisons with chance level (50%): significant difference with chance for scores above or below 50% show a preference for the large or the small reward respectively. Student t-test: ***, +++, °°°, p < .001; **, ++, °°, p < .01; *, +, °, p < .05.