Table 2.

Enrichment odors and drug regimens for the 8 experimental groups of Experiment 2.

Group number	Enrichment odors	Drug regimen	Age (months)
1	(+)-limonene, (−)-limonene	Saline vehicle	2–5
2	(+)-limonene, (−)-limonene	Physostigmine	2–5
3	No odor	Saline vehicle	2–5
4	No odor	Physostigmine	2–5
5	(+)-limonene, (−)-limonene	Saline vehicle	11–14
6	(+)-limonene, (−)-limonene	Physostigmine	11–14
7	No odor	Saline vehicle	11–14
8	No odor	Physostigmine	11–14