Studies on the effects of music on spatial reasoning report conflicting results. Some studies show slight effects, and others show no effects but few seem to replicate the strong findings of the first study published in Rauscher et al. Nature, 365(6447), 611-612, (1993). Nonetheless, the debate about the performance enhancing "Mozart effect" remains to be of great interest. In this study, we manipulated different physical parameters of sound traces (amplitude and frequency) to investigate whether particular dimensions may explain the enhancement effects found in spatial tasks following music listening. To this end, we asked 179 undergraduates and 183 older adults to listen to 5-min sound traces (Mozart KV 448, amplitude modulation tone, frequency modulation tone, white noise) and then complete a spatial reasoning task. In particular, results showed that repetitive frequency changes, as occurring in Mozart's melodies or in a frequency modulation tone, enhance performance.
