Harmonic expectancy violations elicit not-just-right-experiences: A paradigm for investigating obsessive-compulsive characteristics?

Obsessive-compulsive disorder (OCD)-like symptoms are commonly associated with sensations of incompleteness and not-just-right experiences (NJRE). Although NJRE have gained much attention in recent years, most studies have not gone beyond a description of their phenomenology and prevalence also in healthy adults. We applied a validated harmonic expectancy violation paradigm to experimentally investigate NJRE evoked by deviant auditory perceptions. We assessed reaction times (RT) to harmonic and disharmonic chord sequences as well as their emotional appraisal in 64 healthy young adults. The participants clearly indicated disharmonic chord sequences as sounding not-just-right and incomplete and rated them as unpleasant, arousing, and irritating. The RT to disharmonic chord sequences was significantly shorter than the RT to harmonic chord sequences. This effect tended to be greater in those participants who reported stronger general experiences of incompleteness as an underlying core dimension of OCD-like symptoms. In addition, general experience of incompleteness was correlated to the difference between RT to harmonic and that to disharmonic chord sequences, indicating that the intensity of general experience of incompleteness was associated with a more readily activated processing of the deviant auditory perceptions.