Laurel-Yanny Percept Affects the Speech-to-Song Illusion, But Musical Anhedonia Does Not

Some spoken phrases, when heard repeatedly, seem to transform into music, in a classicfinding known as the speech-to-song illusion. Repeated listening to musical phrases can alsolead to changes in liking, attributed to learning-related reduction of prediction errors generatedby the dopaminergic reward system. Does repeating spoken phrases also result in changes inliking? Here we tested whether repeated presentation of spoken phrases can lead to changes inliking as well as in musicality, and whether these changes might vary with reward sensitivity. Wealso asked whether perceptual biases towards low versus high frequencies, as assessed usingthe Laurel/Yanny illusion, are linked to changes in musicality and liking with repetition. Resultsshow a general reduction in liking for spoken phrases with repetition, but less so for phrasesthat transition more readily into song. People who upweight low frequencies in speechperception (and so perceive Laurel rather than Yanny) are more susceptible to changes inmusicality with phrase repetition and marginally less susceptible to changes in liking. Individualswith musical anhedonia still perceived the speech-to-song illusion, but liked all spoken phrasesless; this did not interact with repetition. These results show a dissociation between perceptionand emotional sensitivity to music, and support a model of frequency-weighted internalpredictions for acoustic signals that might drive the speech-to-song illusion. Rather than treatingillusions as isolated curiosities, we can use them as a window into theoretical debatessurrounding models of perception and emotion.