Musical Memory and Alzheimer's Disease

Memory is a vital aspect of identity; it enables individuals to have an enriched understanding of themselves and those most important to them. The most common form of dementia, Alzheimer’s disease, is characterized by the progressive damage of brain cells. The loss of memory because of this degenerative disease causes affected individuals to lose an aspect of their identity. Thus, I have an inherent interest in how any aspect of memory can be preserved in Alzheimer’s disease patients in hopes to improve their quality of life. Recent research progressions have highlighted the possible sparing of musical memory in Alzheimer’s disease, whereby patients remember and sing along to song’s they had heard in the past. Wilder Penfield (1963) was the first theorist to draw traction to the researching of musical memory when he studied the possibility of the temporal cortex having the role of encoding musical memory. The neural foundations of musical memory then became broadly researched, although it was not until later that the correlation between Alzheimer’s disease and the possible sparing of musical memory was studied. Severine Samson has become a prominent researcher in this field, as she theorised that musical memory may be intact in Alzheimer’s disease patients due to the brain regions involved possibly being spared from major damage (Baird & Samson, 2009). Samson also emphasised the difference between implicit and explicit forms of musical memory in a study where individuals diagnosed with Alzheimer’s disease were able to learn to sing a new song over eight different sessions, although they did not remember the sessions themselves: highlighting the likelihood that only implicit musical memory is spared in Alzheimer’s disease (Samson, Baird, Moussard & Clément, 2012). Susan Koger’s research (Brotons & Koger, 2000; Koger, Chapin & Brotons, 1999) into the positive effects of music on mood, language and memory in individuals with dementia has enabled a more broad understanding of the impact music has on improving the quality of life for people with diseases affecting memory. The preservation of musical memory in dementia- with a focus on Alzheimer disease- will be discussed below in detail, referring to three key studies that highlight and emphasise the positive impacts music has on the debilitating disease.

Cuddy and Duffin (2005) conducted a case study that aimed to investigate the possibility of musical memory being spared in dementia patients. The reason for conducting the study was due to the inconsistency between the large body of research concerning musical memory and brain damage, in comparison to the little investigation into the possible sparing of musical memory in dementia patients. This rationale was prevalent, as research often shy’s away from studying dementia patients directly due to the progressive nature of the disease coupled with the obvious issue of standard research methods not being applicable, due to the patient commonly being unable to remember instructions. The research question stemmed from the rationale and asked if the ability to remember previously familiar music is affected in individual’s diagnosed with dementia. A case study was employed which focused on an individual, EN, whom had been previously diagnosed with dementia probable of the Alzheimer’s type. The patient had a history of being deeply devoted to listening to music and was considered an amateur piano player, and anecdotal evidence from EN’s caregivers indicate that her ability to remember familiar music was intact. Three music perception tests from previous literature were adapted to formulate the data needed to test the hypothesis. First, the Familiarity Decision test was conducted, whereby ten familiar and ten unfamiliar song excerpts were played. EN did not respond to those rendered unfamiliar, and only missed one familiar melody which was of French origin and due to her being born and raised in England it is likely she may have not been previously been exposed to this. In comparison to the control data, EN’s scores are indicative of normal functioning musical memory. Secondly, the Distorted Tunes test was conducted where twenty-six popular melodies were played but seventeen of these were altered in pitch. EN responded to the distorted tunes by frowning or laughing. Her score of twenty-five out of twenty-six considers her to have functioning musical memory. Lastly, was the Famous Melodies test where EN was asked to indicate the level of familiarity and name of each song. EN scored just below average in this test, although results could be confounded by song choice as this test was developed for a Canadian sample so she may not have been exposed to all of the music. These findings support the research hypothesis that EN would display a normal functioning musical memory despite her diagnosis of Alzheimer’s disease. The data analysis was clearly correlated with the findings and made sense to what I had previously experienced. My great-grandmother who was diagnosed with Alzheimer’s disease displayed a coherent musical memory, she would often hum and sing songs that she had learned before her memory started to degrade. Thus, this study was particularly interesting to me as a theoretically quantitative research approach was applied to what I had only anecdotally witnessed. The findings were coherently presented with proficient language, and the use of three different tests enabled a broad array of data to be collected. As this research does come from a case study questions regarding whether EN’s results are typical or an exception do make generalising the findings difficult, as well as the inconsistencies with music choice. Although, overall this case study provided a thorough insight into the possibility of a positive correlation for the sparing of musical memory in Alzheimer’s disease.

Dassa and Amir (2014) conducted an observational study that aimed to explore the role of music in encouraging conversation amongst individuals diagnosed with middle to late stage Alzheimer’s disease. The interest in researching the correlation between these two variables stems from the researcher’s personal experience with people diagnosed with Alzheimer’s Disease who have lost the ability to speak because of cognitive decline. Yet, after one musical therapy session these people verbally responded to music. The research questions that guided the data collection focused on what the participants discussed in the sessions as well as what the connection is between the conversation and chosen music choice is. The six participants were randomly selected from residents in an Israeli nursing home, which posed as a limitation for population generalisation as the sample size was small. The qualitative data was collected from eight sessions whereby the therapist sang and encouraged participants to join in, and after each song open-ended questions were posed to facilitate conversation. The songs sang were of Israeli origins released when the participants were adolescent’s; this ensured that majority of the songs were familiar to participants. The participants responses and behaviour within the session was noted by the researcher, who also posed as the music therapist. This acted as another study limitation due to possible author bias as the existing knowledge surrounding Alzheimer’s Disease may have interfered with subjective data collection. Yet, a peer review of the data analysis was undertaken to attempt to control for this. Overall, the study concluded that singing familiar songs did encourage conversation amongst individuals with middle to late stage Alzheimer’s Disease, and participants concentration and engagement was promising due to the disease often inhibits the ability to hold and follow a conversation. As someone who has had a family member affected by this disease, the study was enjoyable to read and correlated with my own experience. There were days where my great grandmother was distressed and sat in silence, and we always knew that singing one of her favourite songs would cause her foot to tap along and slowly she would start commenting about the tune. This research is a promising insight into the positive effects of music on Alzheimer’s Disease patients, and recommendations for future research focused on perhaps studying the role of singing in all stages of the disease rather than middle to late, as well as looking into the emotional impact that music has and how this effects conversational patterns.

Using an alternative approach to the previously analysed studies, Jacobsen et al. (2015) investigated the neural areas typically understood to be involved in musical memory in people with probable Alzheimer’s Disease using functional Magnetic Resonance Imaging (fMRI). The rationale behind conducting this study was due to the lack of objective data collected on this topic, which was prevalent to me as most research investigating Alzheimer’s Disease and musical memory is presented in the form of observational data that is reliant on case studies. The study consisted of two experiments following the same procedure, although the difference was that the first experiment had a sample of thirty-two healthy participants, and the second experiments sample was thirty-four healthy participants and twenty subjects who were speculated to have Alzheimer’s disease: this posed a limitation of the study, as it the participants were not patients diagnosed with the disease. Participants in both experiments were exposed to three different conditions, the first being listening to unknown music, the second was listening to recently known music and the last was listening to long known music. The fMRI measured neural activity whilst the three conditions were conducted. The results supported the research hypothesis, finding that the regions typically involved in the encoding of musical memory are well preserved in Alzheimer’s Disease up until the very late stages. This study provided a good insight into the neural substrates behind the possible sparing of musical memory in Alzheimer’s Disease, and solidifies the need for more objective research to be made in this field rather than relying upon case studies. The language use throughout the study was proficient, although as a reader the reason behind conducting two separate experiments with the same method was not completely clear. The sample size was still small, although it does give a better insight into generalisation that a case study does. In comparison with the findings of the previously discussed observational studies, these findings do make sense and solidify understanding of the sparing of musical memory in Alzheimer’s disease on a neurological level.

The studies analysed support the theory that musical memory is spared in Alzheimer’s disease. Cuddy and Duffin’s (2005) case study enabled an enhanced understanding of this phenomenon through thoroughly focusing on one patient. This study design enabled immense detail to be extracted, although the problem of having a sample consisting of one participant is that generalising the findings to the broader population becomes extremely difficult. Until further research is conducted that reconfigures this method and alters sample size, it is unknown if EN’s results are typical, or if she was an exception. To extend upon this research in the future, Cuddy and Duffin propose that a new procedure that tests musical memory in Alzheimer disease patients needs to be developed that is reliable and quantitative, and considers all possible participants place of birth, age and culture. This will eliminate an element of questioning regarding whether the participants have actually been previously exposed to the music that is labelled as familiar. Dassa and Amir’s (2014) observational study also encounters the issue of small sample size, as this study consisted of six participants. Majority of research within this field has small samples due to the nature of the disease, emphasising the need for a new design to be implemented that enables a larger number of participants without confounding results. Dassa and Amir propose that to broaden the understanding of the relationship between Alzheimer’s disease and musical memory, future research should focus on the earlier stages of the disease to see if possible interventions can affect the progression and onset. To enhance the effectiveness of this research, an element of objective data could be implemented into the studies procedure. Jacobsen et al. (2015) have proposed that this area of research is heavily based on subjective data collection means, and to fuel understanding between variables methodology using non-invasive brain imaging techniques should become more common. The body of research concerning Alzheimer’s disease and musical memory is promising, although there is still so much more that needs to be understood.