Table 1.

Generalized Linear Mixed Effects Models (GLMM) of performance measures on the Cylinder and Barrier tasks. Non-significant interactions (NS) were removed from models prior to determining the test statistic.

model	explanatory variables	Baseline Worm latency	Reward Worm latency	Pecks
1	(a) Opaque versus transparent	X2 = 2.92, p = 0.09	X2 = 72.61, p < 0.01	X2 = 549.07, p < 0.01
1	(b) Task (Cylinder)	X2 = −0.06, p = 0.79	X2 = −372.56, p < 0.01	X2 = −82.91, p < 0.01
1	(c) Improvement across trials	X2 = −10.47, p = 0.01	X2 = −97.10, p < 0.01	X2 = −69.37, p < 0.01
2	(a) Experience (yes)	X2 = −8.26, p = 0.004	X2 = −27.86, p < 0.001	X2 = −14.74, p = 0.0001
3	(a) Persistence	X2 = −1.33, p = 0.25	X2 = 0.65, p = 0.42	X2 = 8.58, p = 0.003
3	(b) Dietary breadth	X2 = −1.50, p = 0.22	X2 = 1.27, p = 0.26	X2 = 5.62, p = 0.018
3	(c) Body Condition	X2 = −0.01, p = 0.92	X2 = 0.91, p = 0.34	X2 = −0.02, p = 0.90
3	(d) Sex (male)	X2 = 1.11, p = 0.29	X2 = −3.08, p = 0.08	X2 = −0.21, p = 0.65
3	(e) Sex (male) * Body Condition	n.s.	n.s.	n.s.