Pre-attentive auditory processing of non-scale pitch in absolute pitch possessors

- We investigated MMN elicited by non-scale note in absolute pitch (AP) possessors.
- MMN elicited by non-scale note was distinct compared to scale note in AP group.
- AP group could discriminate non-scale note from scale note pre-attentively.
- Non-AP group processed scale note and non-scale note in the same way.
- AP may be characterized as preattentive discriminability of non-scale note.

Absolute pitch (AP) refers to the ability to identify the pitch of sound without reference. To clarify the neurophysiological characteristics of AP, we compared mismatch negativity (MMN) elicited by scale and non-scale notes between AP possessors and non-AP individuals. Eight individuals who were able to identify pitch with perfect accuracy were defined as AP possessors. Eighteen participants who failed to achieve perfect accuracy were included in the non-AP group. We presented participants with two tone pairs, in a scale condition and a non-scale condition. The frequency ratios of the two pairs were the same. MMN over the frontal region in the non-scale condition was larger in the AP group than the non-AP group. In contrast, no such difference was observed between the two groups in the scale condition. The results suggest that pre-attentive processing of non-scale note sounds in the auditory cortex is a salient neurophysiological characteristic of AP.