  The Mozart effect refers to scientific data on short-term improvement on
certain mental tasks after listening to Mozart, and also to its popularized
version that listening to Mozart makes you smarter (Tomatis, 1991; Wikipedia,
2012). Does Mozart effect point to a fundamental cognitive function of music?
Would such an effect of music be due to the hedonicity, a fundamental dimension
of mental experience? The present paper explores a recent hypothesis that music
helps to tolerate cognitive dissonances and thus enabled accumulation of
knowledge and human cultural evolution (Perlovsky, 2010, 2012). We studied
whether the influence of music is related to its hedonicity and whether
pleasant or unpleasant music would influence scholarly test performance and
cognitive dissonance. Specific hypotheses evaluated here are that during a test
students experience contradictory cognitions that cause cognitive dissonances.
If some music helps to tolerate cognitive dissonances, then first, this music
should increase the duration during which participants can tolerate stressful
conditions while evaluating test choices. Second, this should result in
improved performance. These hypotheses are tentatively confirmed in the
reported experiments as the agreeable music was correlated with better
performance above that under indifferent or unpleasant music. It follows that
music likely performs a fundamental cognitive function explaining the origin
and evolution of musical ability considered previously a mystery.
