Preserved musical working memory and absolute pitch in posterior cortical atrophy

Working memory for nonverbal auditory information is essential for everyday functioning but its cognitive organisation is not well understood. Here we addressed this issue in a musician, YA, with absolute pitch (AP, the uncommon ability to categorise and label individual musical pitches without an external reference) who developed posterior cortical atrophy. We assessed YA's AP ability and her working memory for pitch and rhythmic patterns using procedures modelled on a standard test of auditory verbal working memory (digit span), referenced to age-matched, cognitively-normal AP and non-AP possessing musicians. YA had retained AP and performed comparably to healthy older AP and non-AP musicians on all musical working memory tasks, despite impaired auditory verbal working memory. These findings suggest that the cognitive mechanisms for auditory verbal working memory, nonverbal (pitch and rhythm) working memory and AP are at least partly dissociable, and both musical working memory and AP can be spared despite posterior parietal degeneration.