Table 2.

Structure of sample list and test list in DNMS

	List position
	1	2	3	4	5	6	7	8
Sample list	A	B	C	D	E	F	G	H
Test list	H versus N1	G versus N2	F versus N3	E versus N4	D versus N5	C versus N6	B versus N7	A versus N8

Note: Eight samples were presented one after another, and monkeys touched each object in the sample list to proceed to the next. The delay between sample objects was 5 s. Having worked through the list of samples, monkeys worked through the test list. The choice stimuli in the test list was presented in reverse order to the list of samples such that the hypothetical alphabetical list of samples A through H, shown above, would be followed by choices H versus N1, G versus N2, F versus N3, E versus N4, D versus N5, C versus N6, B versus N7, and A versus N8, where N1–N8 are always novel objects. The delay between choice trials was always 10 s.