The effects of a simulated fMRI environment on voice intensity in individuals with Parkinson's disease hypophonia and older healthy adults

Premotor cortex is hypoactive during sustained vowel production in individuals with Parkinson’s disease and hypophonia

“…Our previous study ( Manes et al, 2021 ) suggested that our PD participants increased voice SPL to a greater degree than controls when laying supine and listening to MRI noise. Thus, to account for inter-subject differences in Lombard responses during fMRI, we calculated the difference in voice SPL between the “Mock Scanner + MRI Noise” (described above) and the “Upright” conditions in which participants were recorded while seated upright outside of the mock scanner ( Manes et al, 2021 ). This “Lombard response” measure was entered as a covariate in the fMRI analysis.…”

“…In addition, the observation of lower maximum phonation time in PD supports previous studies ( Yuceturk et al, 2002 ; Midi et al, 2008 ; Bauer et al, 2011 ) and may reflect reduced respiratory support for phonation and/or reduced glottal efficiency in PD. When participants performed the sustained vowel production task in a simulated fMRI environment, SPL values were higher than those typically observed during sustained vowel recording due to the effects of laying supine and listening to 90 dB acoustic noise ( Manes et al, 2021 ). The magnitude of the SPL difference between the groups (−4.712 dB SPL) was comparable to the difference of −4.734 dB SPL reported in our previous paper; however, unlike our previous paper, the mixed effects model did not yield a significant effect of group on SPL.…”

“…Recordings for the sustained vowel task were also collected with the participants seated upright and without the presence of fMRI noise. We calculated the difference in SPL between the Mock Scanner + Noise and Upright recording conditions to correct for group differences in the effects of the scanning environment on voice SPL ( Manes et al, 2021 ). The order of fMRI and speech testing was counterbalanced to control for the effects of practice and vocal fatigue.…”

“…Twelve of our thirteen PD participants received perceptual ratings of voice quality as part of a previous behavioral study ( Manes et al, 2021 ). Perceptual ratings were performed using the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V; Kempster et al, 2009 ), which uses a 100 mm analogue scale to rate voice deviance in 5 perceptual domains (roughness, breathiness, strain, pitch, and loudness).…”

“…To accomplish this, we recruited a group of PD participants with hypophonia and a group of age-matched OHC participants to perform a sustained vowel production task while undergoing fMRI. In order to obtain high fidelity measures of voice intensity, participants also performed the same vowel production task outside of the scanner in a simulated MRI environment ( Manes et al, 2021 ). We hypothesized individuals with PD and hypophonia would have significantly lower activity in the LPA, SMA, and premotor cortex compared to age-matched healthy controls and that our acoustic and perceptual measures of phonation would correlate BOLD activity in areas of hypoactivation.…”