This study investigates the functional neuroanatomy of harmonic music perception with fMRI. We presented short pieces of Western classical music to nonmusicians. The ending of each piece was systematically manipulated in the following four ways: Standard Cadence (expected resolution), Deceptive Cadence (moderate deviation from expectation), Modulated Cadence (strong deviation from expectation but remaining within the harmonic structure of Western tonal music), and Atonal Cadence (strongest deviation from expectation by leaving the harmonic structure of Western tonal music). Music compared with baseline broadly recruited regions of the bilateral superior temporal gyrus (STG) and the right inferior frontal gyrus (IFG). Parametric regressors scaled to the degree of deviation from harmonic expectancy identified regions sensitive to expectancy violation. Areas within the BG were significantly modulated by expectancy violation, indicating a previously unappreciated role in harmonic processing. Expectancy violation also recruited bilateral cortical regions in the IFG and anterior STG, previously associated with syntactic processing in other domains. The posterior STG was not significantly modulated by expectancy. Granger causality mapping found functional connectivity between IFG, anterior STG, posterior STG, and the BG during music perception. Our results imply the IFG, anterior STG, and the BG are recruited for higher-order harmonic processing, whereas the posterior STG is recruited for basic pitch and melodic processing.

Persistent developmental stuttering affects close to 1% of adults and is thought to be a problem of sensorimotor integration. Previous research has demonstrated that individuals who stutter respond differently to changes in their auditory feedback while speaking. Here we explore a number of changes that accompany alterations in the feedback of pitch during vocal production. Participants sustained the vowel /a/ while hearing on-line feedback of their own voice through headphones. In some trials, feedback was briefly shifted up or down by 100 cents to simulate a vocal production error. As previously shown, participants compensated for the auditory pitch change by altering their vocal production in the opposite direction of the shift. The average compensatory response was smaller for adults who stuttered than for adult controls. Detailed analyses revealed that adults who stuttered had fewer trials with a robust corrective response, and that within the trials showing compensation, the timing of their responses was more variable. These results support the idea that dysfunctional sensorimotor integration in stuttering is characterized by timing variability, reflecting reduced coupling of the auditory and speech motor systems.

Speech timing deficits have been proposed as a causal factor in the disorder of stuttering. The question of whether individuals who stutter have deficits in nonspeech timing is one that has been revisited often, with conflicting results. Here, we uncover subtle differences in a manual metronome synchronization task that included tempo changes with adults who stutter and fluent speakers. We used sensitive circular statistics to examine both asynchrony and consistency in motor production. While both groups displayed a classic negative mean asynchrony (tapping before the beat), individuals who stutter anticipated the beat even more than their fluent peers, and their consistency was particularly affected at slow tempi. Surprisingly, individuals who stutter did not have problems with interval correction at tempo changes. We also examined the influence of music experience on synchronization behavior in both groups. While music perception and training were related to synchronization behavior in fluent participants, these correlations were not present for the stuttering group; however, one measure of stuttering severity (self‐rated severity) was negatively correlated with music training. Overall, we found subtle differences in paced auditory−motor synchronization in individuals who stutter, consistent with a timing problem extending to nonspeech.

https://doi.org/10.23641/asha.5895997.