APOE and Alzheimer disease: Given that SPG is associated with voice severity in essential tremor (De Lima Xavier and Simonyan 2020), auditory integration for vocal pitch regulation (Chen et al. 2021), and long‐term delayed recall (Ma et al. 2023), we speculate that APOE ε4 allele may cause inflexible connectivity between the right SPG/PCUN/brodmann area 7 and neighboring brain regions during the integration, processing, and analysis of cognitive information in AD patients.