. Author manuscript; available in PMC: 2009 Feb 1.

Published in final edited form as: Behav Processes. 2007 Dec 3;77(2):199–209. doi: 10.1016/j.beproc.2007.11.009

Table 2.

Mean percentage of errors to the choice keys associated with the four different shapes during discrimination training in Experiment 1

Choice key	Presented stimulus
	Arch	Barrel	Brick	Wedge
Arch		24.4^!	42.0	21.6^!
Barrel	16.2^!		22.2	33.7
Brick	57.6^*	39.1		44.8^*
Wedge	26.1	36.6	35.9

Note: Asterisks and exclamation points signify values that were significantly above and below chance levels, respectively, according to two-tailed t-tests for proportions.