. 2000 Jul 15;20(14):5526–5537. doi: 10.1523/JNEUROSCI.20-14-05526.2000

Table 2.

Slopes of firing rates over progressive ratio and fixed ratio sessions

LPE cells	Window	Slope (PR)	Slope (FR)
	Before lever pressing	3.50^*	−0.33
	During lever pressing	3.92^*	−0.62
	After reward	3.67^*	0.07
LPI Cells	Window	Slope (PR)

	During lever pressing	2.84
	Around peak	1.02

Slope units are percent increase per reward. Asterisk indicates slope is significantly different from 0 (linear regression,p < 0.001). For LPE cells, ANCOVA to compare PR slopes resulted in F_(2,875) = 0.054,p > 0.9, indicating that slopes did not significantly differ. ANCOVA to compare FR slopes was not performed because none of the slopes were significantly different from 0 (linear regression,p > 0.05).