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Abstract:
Situational stressors and anxiety impede performance on
"creativity" tests requiring cognitive flexibility. Previous
research has suggested that the noradrenergic system modulates
cognitive flexibility. However, whether this is specific to the
noradrenergic system or a nonspecific effect of anxiety is unknown.
In order to determine whether noradrenergic modulation of cognitive
flexibility is due to a nonspecific anxiety effect, we compared the
effects of propranolol (b-blocker), lorazepam (GABAergic
anxiolytic), and placebo on performance of the anagram task. Each
subject attended three test sessions, one week apart. Prior to each
test session, the subjects were given one of the three drugs.
Eighteen normals received a 1mg dose of lorazepam. Three subjects
received a 2mg dose. Time taken to complete each test item was
recorded. The natural log of each of the test item solution times
was summed for each test session. These test session scores were
compared across the drug conditions using analysis of variance
(ANOVA). Subjects receiving the 2mg dose of lorazepam performed
significantly worse than placebo (p=0.014). At the 1mg dose, for
subjects best able to solve the anagrams, lorazepam did not
significantly differ from placebo. However, solution times after
propranolol were significantly lower than after placebo (p=0.015).
This suggests that the modulatory influence of the noradrenergic
system on cognitive flexibility does not result from a nonspecific
effect of anxiety.
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