Pitch as a Shared Code for Music and Speech: Behavioral and Neural Evidence From Stroke Patients

INTRODUCTION: Accurate pitch processing, including the ability to discriminate small differences in pitch, is essential for interpreting the melodic structure of both music and speech. However, the extent to which pitch discrimination is a shared auditory-perceptual processing component in these domains remains unclear. METHODS: This clinical study explored pitch discrimination, musical pitch perception, and linguistic and affective prosody perception in 39 stroke patients. Behavioral testing was performed during both early subacute (within 3 weeks of stroke) and late subacute (3 months post-stroke) stages, and whole‑brain white matter connectome analyses of early acute stage diffusion MRI data were conducted to identify shared neural substrates of these auditory functions. In addition, prognostic analyses were carried out examining whether early subacute white matter integrity predicted late subacute pitch‑related outcomes. RESULTS: Across both stages, pitch discrimination showed robust associations with musical pitch perception and both linguistic and affective prosody perception. Deviation-specific analyses indicated that the 50-cent pitch discrimination threshold was the most sensitive index of individual differences, showing the strongest and most consistent associations with musical and prosodic abilities. Early subacute cross-sectional connectome analyses revealed overlapping neural substrates: better performance across all four auditory domains was linked to greater integrity of the right inferior fronto‑occipital fasciculus (IFOF) and corticospinal tract, with additional associations in the right arcuate and uncinate fasciculi for musical pitch and prosody measures. In prognostic analyses, integrity of the IFOF and uncinate fasciculus at < 3 weeks significantly predicted 3‑month performance across all measured pitch parameters. CONCLUSION: These results point to overlapping behavioral and neural associations related to pitch-based perception, underscoring its importance in both music and speech domains.