Table 2.

HAD rats are more sensitive to delayed or probabilistic outcomes.

	Delay Discounting		Probability Discounting
	Bias	k	Bias	k
HAD1	1.28 ± 0.04***	0.53 ± 0.07**	1.14 ± 0.10*	0.76 ± 0.19*
HAD2	1.36 ± 0.09***	0.40 ± 0.07**	1.12 ± 0.09*	0.53 ± 0.19*
LAD1	0.99 ± 0.09	0.20 ± 0.06	1.00 ± 0.12	0.25 ± 0.04
LAD2	0.80 ± 0.11	0.25 ± 0.04	0.76 ± 0.14	0.44 ± 0.30

Data shown are the mean ± SEM for bias (b) and discount parameter (k) values as derived from the hyperbolic discount function (Equation 1). Higher values of k indicate greater sensitivity to delayed or probabilistic outcomes. Bias values above one indicate a preference for the cost (uncertain or delayed) lever and bias values below 1.0 indicate a preference for the certain or immediate lever. HAD1 n = 6, HAD2 n = 6, LAD1 n = 6, LAD2 n = 5. Significant line differences are denoted as follows,

^*p < 0.05,

^**p = 0.001,

^***p < 0.001