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. 2011 Jan 11;36(3):223–235. doi: 10.1093/chemse/bjq128

Figure 3.

Figure 3

Comparing innate behavior to associative learnability: AM–3OCT. (A) Innate preference: Experimentally naïve animals are given the choice between an odor and a no odor condition (EM). Larvae approach both undiluted AM and undiluted 3OCT when tested against EM (OSS tests: P < 0.05/2; N = 16, 16) and, statistically, do so to the same extent (MWU-test: U = 85.5; P = 0.11; N = 16, 16). The shading of the boxes indicates significant difference from chance level (OSS tests above). (B) Relative innate preference: When undiluted AM is tested against undiluted 3OCT in a relative choice situation, larvae strongly prefer AM over 3OCT (OSS test: P < 0.05/7; N = 22). Along a dilution series of AM, this preference for AM is lost at AM: paraffin dilutions between 1:3 and 1:30 (OSS tests: P > 0.05/7; N = 18, 16, 16, 18). At dilutions of 1:100 and 1:1000, larvae prefer 3OCT over AM (OSS tests: P < 0.05/7; N = 14, 20). The shading of the boxes indicates significant difference from chance level (OSS tests above). Based on these results, we chose a 1:20 dilution of AM for testing AM and 3OCT for learnability. (C) Learnability: Both odors, at the respective intensities, are learnable (OSS tests: P < 0.05/2; N = 22, 21). Higher associative performance indices are seen for AM than for 3OCT (MWU-test: U = 149.0; P < 0.05; sample sizes as above), even though their innate relative preference had been titrated against (see B). When after differential conditioning between AM and 3OCT, the better-learnable AM is omitted at test, associative performance indices are reduced (group 3 vs. 5, MWU-test: U = 122.0; P < 0.05/2; N = 24, 23); if, in turn, the less-learnable odor 3OCT is omitted, scores are not significantly reduced when using the warranted Bonferroni correction (group 3 vs. 4, MWU-test: U = 184.0; P = 0.05; N = 24, 23) (a KW test across the 3 groups yields: H = 11.14; degrees of freedom = 2; P < 0.05; sample sizes as above). Other details as in the legend of Figure 2. This figure appears in color in the online version of Chemical Senses.