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Reward modulation of cognitive function: the nucleus accumbens
Results
Discrimination training
A repeated measures GLM with the factor accuracy (correct vs. incorrect) confirmed that,
by the end of training, animals were able to reliably discriminate between the two auditory
stimuli (F(1,23) = 77.400, p < 0.001, η2 =0.771) and between the two visual stimuli (F(1,23)
= 19..949, p < 0.001, η2 = 0.464;
Table 6.3
). Reliable discrimination between the correct and
incorrect lever was achieved during day 2 of training on the auditory training and from day 8
onwards for the visual discrimination training (
Table 6.3
).
Reward context can alter task-switching performance
Importantly, animals were able to use the task cue to successfully discriminate between the
response-incongruent stimuli, which was reflected by a main effect of accuracy (correct vs.
incorrect lever presses: (F(1,23) = 4.667, p = 0.041, η2 = 0.169). We did not observe a main
effect of reward or of task-switching in terms of accuracy (F < 1).
The reward context affected task-switching performance. More specifically, animals were
better at switching between the auditory and visual modalities in each compound stimulus
a
-2
0
2
4
Switch
Repeat
(correct > incorrect)
High
Low
Reward
Switching
improved performance
Accuracy
Figure 6.2
Task switching differences in the high versus low reward context
A: For each reward context (high and low), the performance on switch and repeat trials is shown. The y
axis represents the number of correct vs. incorrect lever presses (per minute), recorded during the first
10s of each trial. Error bars represent standard errors of the difference between correct and incorrect
responses.