PREMUS comprised of four parallel studies exploring (i) the effects of ageing and singing experience on the neural processing of singing, speech, and music (Study 1), (ii) the long-term efficacy of choir singing on neurocognitive ageing (Study 2), the preservation of singing ability and the rehabilitative efficacy of a singing intervention in aphasia (Study 3), and (iv) the preservation of music-evoked emotions and memories in different stages of Alzheimer’s disease dementia (Study 4). Led by the Principal Investigator (Prof. Teppo Särkämö), the work in PREMUS is mainly carried out by the Music, Ageing and Rehabilitation Team (MART, link: www.helsinki.fi/en/researchgroups/music-ageing-and-rehabilitation-team) at the Cognitive Brain Research Unit (CBRU) in University of Helsinki.
During PREMUS, we successfully collected data from a total of 608 subjects (Study 1: 100 healthy adults, Study 2: 200 healthy older adults, Study 3: 79 persons with chronic aphasia & 55 family caregivers, Study 4: 144 persons with dementia & 30 healthy controls). The collected data were obtained from neuropsychological tests, questionnaires, electroencephalography (EEG) measurements, and structural (sMRI) and functional (fMRI) magnetic resonance imaging measurements implemented using cross-over (Studies 1 & 4), longitudinal (Study 2), and randomized controlled trial (RCT, Study 3) designs. In Study 4, the COVID-19 pandemic unfortunately delayed the onset of data collection, which is still ongoing, and no published results are reported yet from that study. Due to the lockdown period during the pandemic, the work in PREMUS also focused on further data analysis and reporting from a previous RCT focusing on the rehabilitative effects of daily vocal music listening during early stroke recovery, closely linked to the theme of Study 3.
The results of Studies 1-2 showed that in healthy older adults (i) the singing network of the brain undergoes less functional reorganisation (in terms of lateralization and engagement of the prefrontal cortex) in normal ageing compared to the speech network, especially when the task is cognitively demanding, (ii) regular choir singing is associated with better cognitive functioning (executive function, episodic memory) and emotional wellbeing (depression, social integration, quality of life) as well as with enhanced auditory processing of sound features relevant to choir singing (pitch and location) and structural connectivity in multiple left and right hemisphere white matter pathways, and (iii) music-evoked autobiographical memories are strongly linked to the emotional experience of the songs, mediated by same core musical (rhythmic, tonal, timbral) features, as well as to memories of music-related activities (e.g. singing, dancing, listening) from adolescence years.
The RCT results from Study 3 and our previous study on music listening provided novel evidence that (i) stroke patients with chronic aphasia can often retain their ability to produce words by singing, even in severe aphasia, facilitated by the preservation of left temporal lobe regions and structural connectivity in the left ventral stream, (ii) in chronic aphasia, a multicomponent singing intervention using choir singing, melodic intonation therapy, and home training improves communication, speech, social participation, and caregiver wellbeing and increases grey matter volume and structural connectivity in the frontal lobe parts of the language network, and (iii) in subacute aphasia, also daily listening to vocal (sung) music improves the verbal memory and language recovery and induces structural and functional neuroplasticity in the left language network, and (iv) musical deficits caused by stroke (acquired amusia) are linked to damage in right temporal regions and disconnection of the right ventral stream.
The outcomes of PREMUS have been published in 51 journal articles, 3 PhD theses, and 13 Master’s theses and disseminated in 45 conference/workshop presentations, 25 training lectures for professionals and students, 35 lectures for the general public and other stakeholders, and 55 media communications.