SENSORY PRECONDITIONING
Avoidance but not aversion following sensory preconditioning with flavors:
A challenge to stimulus substitution
Supplementary Data:
From pre-exposure, aversion training, and test expressed as a function of solution type.
D.M. Dwyer, K.V. Burgess, & R.C. Honey
Cardiff University
Short Title: SENSORY PRECONDITIONING
Submitted in May 2012 to:
Journal of Experimental Psychology: Animal Behavior Processes
Address for correspondence:
School of Psychology
Cardiff University
Tower Building, Park Place
Cardiff
CF10 3AT, UK
Tel: +44 (0)29 2087 6285
Email: DwyerDM@cardiff.ac.uk, BurgessK1@cardiff.ac.uk, Honey@cardiff.ac.uk
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SENSORY PRECONDITIONING
Experiment 1
Data from exposure (AB and CD pairing trials) and aversion training (A+ and Ctrials) are shown in Supplementary Table 1. The exposure data (consumption and lick cluster
size separately) were subjected to mixed ANOVAs with a within-subject factor of trial type
(AB or CD) and a between-subjects factor of solution assignment (AC = Suc/Malt or AC =
Salt/Lem). For consumption, there were no significant main effects or interactions (all Fs <
1). For lick cluster size, there were also no significant main effects or interactions (largest
F(1,22) = 1.75, p = .199, MSE = 84.61, for the interaction).
The aversion training data were also subjected to mixed ANOVAs with a withinsubject factor of trial type (A+ or C-) and a between subjects factor of solution assignment
(AC = Suc/Malt or AC = Salt/Lem). For consumption, there was a significant effect of
solution assigment, F(1,22) = 17.57, p < 0.001, MSE = 5.40, reflecting lower consumption
when the A/C solutions came from the salt and lemon pair rather than the sucrose and
maltodextrin pair. There was no main effect of trial type, or interaction (largest F(1,22) =
1.03, p = .321, MSE = 13.68, for main effect of trial type). For lick cluster size, were no
significant main effects or interactions (largest F(1,22) = 1.49, p = .235, MSE = 214.51, for
the interaction).
Data from the test trials with stimuli A-D, split as factor of whether A and C were
sucrose and maltodextrin or salt and lemon, are shown in Supplementary Table 1. These data
were subjected to mixed ANOVAs with within-subject factors of aversion condition (i.e.
whether the stimuli should be subject to an aversion or not: A & B versus C & D) and
training type (direct conditioning or sensory preconditioning: A & C versus B & D), plus a
between-subjects factor of solution assignment (AC = Suc/Malt or AC = Salt/Lem). The
main manuscript reports the analysis of this data collapsed over the factor of solution
assignment (see data in Figure 1 and inferential analyses in the result section of Experiment
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SENSORY PRECONDITIONING
1), thus only the effects of solution assignment and its interactions will be considered here.
For consumption, the the interaction between solution assignment and training type was
significant, F(1,22) = 25.57, p < .001, MSE = 0.91, but no other main effects or interactions
involving the solution assignment factor were significant (all Fs < 1). The significant
interaction reflects that fact that less of the A and C solutions was consumed than of the B
and D solutions, but that this difference was smaller when A and C were sucrose and
maltodextrin. There were no significant effects or interactions involving the solution
assignment factor for the analysis of lick cluster size (Fs < 1).
In summary, the counterbalancing factor of whether the solutions sucrose and
maltodextrin, or lemon and salt, were assigned to be stimuli A and C or stimuli B and D
influenced the amount of A and C consumed during aversion training, and the amount of A
and C consumed relative to B and D during test. Critically, it did not interact with aversion
conditioning in any way and so there is no suggestion that it could have influenced the
analysis of aversions produced by direct or sensory preconditioning as described in the main
manuscript. The absence of any effects of solution assigment on the lick cluster measure
suggests that, possibly due to due to water deprivation enhancing the value of all fluids,
unconditioned differences between solution types had relatively little impact on this factor.
Experiment 2
Data from exposure (AB and CD pairing trials) and aversion training (A+ and C- trials)
are shown in Supplementary Table 2. The exposure data (consumption and lick cluster size
separately) were subjected to mixed ANOVAs with a within-subject factor of trial type (AB
or CD) and between-subjects factors of LiCl strength (Low or High) and of solution
assignment (AC = Suc/Malt or AC = Salt/Lem). For consumption, the main effect of trial
type approached standard levels of significance, F(1,44) = 2.93, p = .094, MSE = 6.22,
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SENSORY PRECONDITIONING
reflecting the numerically greater consumption during AB than CD trials. No other main
effects or interactions were significant (largest F(1,44) = 1.40, p = .243, MSE = 6.22, for the
trial type by solution assignment interaction). For lick cluster size, there was a significant
effect of LiCl strength, F(1,44) = 4.24, p = .045, MSE = 112.16, reflecting the fact that rats in
the group to be injected with high doses of LiCl had lower lick cluster sizes than rats in the
group to be injected with low doses of LiCl. The effect of solution assignment approached
significance, F(1,44) = 2.84, p = .090, MSE = 112.16, reflecting the fact that rats in the AC =
Suc/Malt sub-group showed numerically lower lick cluster sizes. No other main effects or
interactions were significant (largest F(1,44) = 1.80, p = .186, MSE = 88.19, for the trial type
by solution assignment interaction).
The aversion training data were also subjected to mixed ANOVAs with a within-subject
factor of trial type (A+ or C-) and between-subjects factors of LiCl strength (Low or High)
and of solution assignment (AC = Suc/Malt or AC = Salt/Lem). For consumption, there was
a significant effect of solution assigment, F(1,44) = 27.96, p < 0.001, MSE = 6.71, reflecting
lower consumption when the A/C solutions came from the salt and lemon pair rather than the
sucrose and maltodextrin pair. There were no other significant main effects or interactions
(largest F(1,44) = 1.74, p = .194, MSE = 6.71, for the LiCl strength by solution assignment
interaction). For lick cluster size, there were no significant main effects or interactions
(largest F(1,44) = 2.49, p = .122, MSE = 118.06, for the main effect of LiCl strength).
Data from the test trials with stimuli A-D, split as factor of whether A and C were
sucrose and maltodextrin or salt and lemon, is shown in Supplementary Table 2. These data
were subjected to mixed ANOVAs with within-subject factors of aversion condition (i.e.
whether the stimuli should be subject to an aversion or not: A & B versus C & D) and
training type (direct conditioning or sensory preconditioning: A & C versus B & D), plus
between subjects factors of LiCl strength (Low or High) and solution assignment (AC =
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SENSORY PRECONDITIONING
Suc/Malt or AC = Salt/Lem). Again, the main manuscript reports the analysis of these data
collapsed over the factor of solution assignment (see data in Figure 2 and inferential analyses
in the result section of Experiment 2), thus only the effects of solution assignment and its
interactions will be considered here. As in Experiment 1, for consumption, the interaction
between solution assignment and training type was significant, F(1,44) = 37.60, p < .001,
MSE = 3.60, but no other main effects or interactions involving the solution assignment
factor were significant (largest F(1,44) = 1.69, p = .201, MSE = 10.40, for the main effect of
solution assignment). Again, the significant interaction reflects that fact that less of the A
and C solutions was consumed than of the B and D solutions, but that this difference was
smaller when A and C were sucrose and maltodextrin. For the analysis of lick cluster size
data, there was a signifcant interaction between LiCl strength and solution assignment
F(1,44) = 6.66, p = .013, MSE = 350.85 (reflecting the fact that for the Low LiCl group the
AC = Suc/Malt group had numerically lower lick cluster sizes than the AC = Salt/Lem group
and that this was reversed for the High LiCl group), and also a significant 3-way interaction
between solution assignment, aversion condition and training type, F(1,44) = 5.06, p = .030,
MSE = 187.12. This reflected a modulation of the 2-way interaction between aversion
condition and training type, whereby difference between cluster sizes for A and C was
smaller for the AC = Suc/Malt than the AC = Salt/Lem group (though still significant in both
cases, F(1,44) = 11.79, p < .001, MSE = 16.13 and F(1,44) = 48.77, p < .001, MSE = 16.13,
respectively) and the differences between cluster sizes for B and D was larger for the AC =
Suc/Malt than the AC = Salt/Lem group (though not approaching standard levels of
significance in either case, largest F(1,44) = 1.08, p = .303, MSE = 13.82).
In summary, the counterbalancing factor of whether the solutions sucrose and
maltodextrin, or lemon and salt, were assigned to be stimuli A and C or stimuli B and D
influenced the amount of A and C consumed during aversion training, and the amount of A
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SENSORY PRECONDITIONING
and C consumed relative to B and D during test. Critically, it did not interact with aversion
conditioning in any way. Although there were effects of solution assignment on lick cluster
size in this experiment, the critical result whereby there was an effect of this measure for
direct conditioning, but not sensory preconditioning, was present in both of the
counterbalancing subgroups. Again, there is no suggestion that the assignment of stimulus
conditions to flavour stimuli could have influenced the analysis of aversions produced by
direct or sensory preconditioning, as described in the main manuscript.
Experiment 3
Data from exposure (AB and CD pairing trials) and aversion training (A+ and C- trials)
are shown in Supplementary Table 3. The exposure data (consumption and lick cluster size
separately) were subjected to mixed ANOVAs with a within-subject factor of trial type (AB
or CD) and between-subjects factors of LiCl delivery (immediate or trace), and of solution
assignment (AC = Suc/Malt or AC = Salt/Lem). For consumption, there were no significant
main effects or interactions (largest F(1,28) = 1.05, p = .315, MSE = 11.69, for the trial type
by LiCl delivery interaction). For lick cluster size, no main effects or interactions were
significant (largest F(1,28) = 2.67, p = .113, MSE = 108.72, for the trial type by solution
assignment interaction).
The aversion training data were also subjected to mixed ANOVAs with a within-subject
factor of trial type (A+ or C-) and between-subjects factors of LiCl delivery (immediate or
trace) and of solution assignment (AC = Suc/Malt or AC = Salt/Lem). For consumption, the
effect of solution assigment approached conventional levels of statisitcal significance,
F(1,28) = 3.96, p = 0.057, MSE = 8.33, and there was a signifcant interaction between
solution assignment and LiCl deivery, F(1,28) = 7.20, p = 0.012, MSE = 8.33. This reflected
lower consumption when the A/C solutions came from the salt and lemon pair rather than the
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SENSORY PRECONDITIONING
sucrose and maltodextrin pair in the trace group but not the immediate group. There were no
other significant main effects or interactions (Fs < 1). For lick cluster size, there were no
significant main effects or interactions (largest F(1,28) = 2.87, p = .101, MSE = 452.00, for
the three way interaction between trial type, LiCl delivery, and solution assignment).
Data from the test trials with stimuli A-D, split as factor of whether A and C were
sucrose and maltodextrin, or salt and lemon, are shown in Supplementary Table 3. These
data were subjected to mixed ANOVAs with within-subject factors of aversion condition (i.e.
whether the stimuli should be subject to an aversion or not: A & B versus C & D) and
training type (direct conditioning or sensory preconditioning: A & C versus B & D), plus the
between-subjects factors of LiCl delivery (immediate or trace) and solution assignment (AC
= Suc/Malt or AC = Salt/Lem). Again, the main manuscript reports the analysis of this data
collapsed over the factor of solution assignment (see data in Figure 3 and inferential analyses
in the result section of Experiment 3), thus only the effects of solution assignment and its
interactions will be considered here. For consumption, the interaction between solution
assignment and training type was significant, F(1,28) = 13.62, p = .001, MSE = 3.66, but no
other main effects or interactions involving the solution assignment factor were significant
(largest F(1,28) = 2.23, p = .146, MSE = 13.52, for the interaction between LiCl delivery and
solution assignment). As in the previous experiments, the significant interaction reflects that
fact that less of the A and C solutions was consumed than of the B and D solutions, but that
this difference was smaller when A and C were sucrose and maltodextrin. There were no
significant main effects or an interaction involving the factor of solution assignment for the
analysis of lick cluster size (Fs < 1).
In summary, the counterbalancing factor of whether the solutions sucrose and
maltodextrin, or lemon and salt, were assigned to be stimuli A and C or stimuli B and D
influenced the amount of A and C consumed during aversion training, and the amount of A
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SENSORY PRECONDITIONING
and C consumed relative to B and D during test but did not interact with aversion
conditioning in any way. Again, there is no suggestion that the assignment of stimulus
conditions to flavour stimuli could have influenced the analysis of aversions produced by
direct or sensory preconditioning that were described in the main manuscript.
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SENSORY PRECONDITIONING
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SENSORY PRECONDITIONING
Supplementary Table 1: Experiment 1
AB
CD
A+
C-
Exposure &
Aversion
Training
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
9.3 (0.8)
28.6 (1.9)
8.7 (0.6)
29.5 (2.8)
11.6 (0.6)
33.1 (3.0)
12.7 (0.4)
41.4 (3.3)
AC = Salt/Lem
8.9 (0.8)
31.2 (3.9)
8.5 (0.6)
25.1 (2.3)
8.8 (1.1)
33.5 (3.6)
9.9 (1.2)
35.5 (5.5)
A
B
C
D
Test
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
2.5 (0.4)
16.6 (1.8)
7.8 (1.1)
36.4 (5.4)
12.4 (0.7)
44.8 (3.7)
10.5 (1.4)
41.5 (5.9)
AC = Salt/Lem
2.5 (0.7)
16.2 (3.8)
9.4 (0.5)
31.0 (3.3)
11.3 (1.0)
42.6 (5.6)
11.6 (0.5)
38.9 (4.3)
Note: A-D refer to the test solutions (see Table 1 of the main manuscript for the exact design). AB and CD refer to the data averaged across the
three AB and CD exposure sessions. A+ and C- refer to the data from the aversion training sessions (where LiCl was injected following
consumption of A but not C). A, B, C, and D refer to data from the test sessions. AC = Suc/Malt refers to the solution counterbalancing where
animals received sucrose and maltodextrin as either A or C (and thus received salt and lemon as B or D). AC = Salt/Lem refers to the solution
counterbalancing where animals received salt and lemon as either A or C (and thus received sucrose and maltodextrin as B or D).
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SENSORY PRECONDITIONING
Supplementary Table 2: Experiment 2
AB
CD
A+
C-
Exposure &
Aversion
Training
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
10.6 (0.4)
35.9 (3.3)
9.3 (0.6)
32.5 (2.9)
11.8 (1.1)
34.6 (3.9)
11.5 (0.5)
34.2 (2.7)
AC = Salt/Lem
9.7 (0.4)
36.8 (3.9)
9.3 (0.7)
34.0 (3.2)
8.3 (1.2)
29.6 (3.8)
7.8 (0.9)
28.4 (3.1)
AC = Suc/Malt
10.4 (0.6)
27.3 (2.3)
8.8 (0.9)
27.3 (2.1)
11.2 (0.5)
39.5 (3.7)
10.4 (0.5)
29.8 (2.0)
AC = Salt/Lem
9.9 (0.6)
31.4 (1.6)
9.7 (0.7)
35.4 (3.1)
8.8 (1.3)
35.0 (3.0)
8.7 (1.0)
36.5 (5.4)
Low LiCl
High LiCl
A
B
C
D
Test
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
5.6 (1.0)
28.6 (2.9)
8.0 (0.9)
38.1 (5.2)
10.6 (0.9)
39.7 (4.2)
9.1 (1.0)
42.6 (4.0)
AC = Salt/Lem
3.8 (1.1)
17.8 (3.9)
10.1 (0.8)
29.4 (1.8)
10.5 (1.0)
36.7 (2.9)
10.9 (0.6)
31.5 (2.1)
AC = Suc/Malt
4.5 (1.0)
20.0 (4.0)
7.0 (1.2)
33.7 (4.9)
10.1 (0.5)
36.5 (3.0)
8.3 (0.7)
36.9 (4.1)
AC = Salt/Lem
2.6 (0.8)
13.2 (2.5)
8.4 (1.1)
43.5 (5.6)
9.7 (0.8)
50.5 (7.5)
12.1 (0.6)
42.1 (4.8)
Low LiCl
High LiCl
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SENSORY PRECONDITIONING
Note: A-D refer to the test solutions while Low and High refer to the LiCl doses used (see Table 1 of the main manuscript for the exact design).
AB and CD refer to the data averaged across the three AB and CD exposure sessions. A+ and C- refer to the data from the aversion training
sessions (where LiCl was injected following consumption of A but not C). A, B, C, and D refer to data from the test sessions. AC = Suc/Malt
refers to the solution counterbalancing where animals received sucrose and maltodextrin as either A or C (and thus received salt and lemon as B
or D). AC = Salt/Lem refers to the solution counterbalancing where animals received salt and lemon as either A or C (and thus received sucrose
and maltodextrin as B or D).
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SENSORY PRECONDITIONING
Supplementary Table 3: Experiment 3
AB
CD
A+
C-
Exposure &
Aversion
Training
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
9.7 (1.0)
28.2 (4.6)
9.1 (0.7)
30.1 (3.8)
11.1 (1.9)
49.5 (6.1)
11.6 (1.2)
37.7 (6.1)
AC = Salt/Lem
10.9 (1.2)
24.7 (4.0)
9.6 (1.3)
33.5 (3.9)
11.8 (2.0)
38.0 (4.5)
11.8 (2.1)
55.2 (14.4)
AC = Suc/Malt
9.4 (0.9)
28.9 (8.0)
10.9 (1.0)
25.4 (3.4)
14.1 (0.8)
42.1 (5.7)
13.5 (0.6)
37.0 (8.2)
AC = Salt/Lem
9.6 (0.9)
27.7 (3.3)
9.9 (1.4)
34.5 (6.1)
10.1 (1.8)
47.4 (9.0)
10.7 (1.7)
35.3 (6.8)
Immediate
Trace
A
B
C
D
Test
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
Consumption
Cluster Size
AC = Suc/Malt
2.3 (0.5)
10.1 (2.1)
7.5 (1.4)
40.4 (7.5)
12.5 (0.9)
45.9 (5.6)
9.6 (1.4)
38.4 (4.8)
AC = Salt/Lem
2.9 (0.9)
15.0 (3.3)
9.7 (0.9)
39.6 (4.7)
12.4 (2.2)
51.0 (8.3)
12.8 (1.2)
37.7 (5.2)
AC = Suc/Malt
4.9 (1.0)
14.9 (5.2)
8.5 (1.9)
44.1 (12.7)
14.7 (1.5)
40.5 (6.5)
12.1 (1.9)
33.9 (5.3)
AC = Salt/Lem
5.1 (1.7)
15.5 (5.5)
10.2 (0.6)
38.7 (8.9)
11.0 (1.1)
38.0 (5.2)
12.0 (0.7)
32.3 (6.1)
Immediate
Trace
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SENSORY PRECONDITIONING
Note: A-D refer to the test solutions while Immediate and Trace refer to the interval between the presentation of A and injection with LiCl (see
Table 1 of the main manuscript for the exact design). AB and CD refer to the data averaged across the three AB and CD exposure sessions. A+
and C- refer to the data from the aversion training sessions (where LiCl was injected following consumption of A but not C). A, B, C, and D
refer to data from the test sessions. AC = Suc/Malt refers to the solution counterbalancing where animals received sucrose and maltodextrin as
either A or C (and thus received salt and lemon as B or D). AC = Salt/Lem refers to the solution counterbalancing where animals received salt
and lemon as either A or C (and thus received sucrose and maltodextrin as B or D).
14