Music and its impact on dementia
Music is an integral part of our lives, not only does it seems to ‘lift our spirit’ but also enhance our lives on so many levels. The same is true for people with dementia, where there has been an increasing focus on music, and specifically music therapy, to improve the quality of life of people with dementia or even improve their symptomology. But how does actually elicit music these positive aspects in our brain? And how does this potentially help people with dementia?
Let’s find out.
What is music?
There are very few people on this earth who do not like music. Indeed, one can see music as not only integral to our culture but also what makes us human. Researchers have claimed for a long time that humans are the only species, which has developed music as part of their cultural life. (Although I am always a bit wary of such anthropomorphic self-congratulation. Just remember when it was claimed that tool use was specific to humans but then was found that apes and even birds use tools all the time. The same might be true for music. Let’s not forget that birds ‘sing’ their songs.) Regardless, for now, let’s bask in our ingenious invention of music.
But what is actually music?
Music in its essence can be defined as consisting of two structural elements: i) the ‘beat’ (basically a rhythm) and ii) the scale (an organisation of pitches in ascending or descending order). In most cases, the beat and scale are interwoven, creating a rich tapestry of auditory information. Research has shown that a beat closest to our heartbeat seems to elicit a very strong response in humans, highlighting that music is not only eliciting an emotional or aesthetic response in us but also a physiological response, including movement (who could not stop themselves from tapping their foot to a song – even though you might actually not like the song). Indeed, the most popular time signature/beat across all songs is 4/4, which equates to 60 beats per minute – similar to our resting heart rate – indicating that we find this type of music most relaxing.
Another key aspect of music is that it has a strong social component. Yes, we can put on our headphones and enjoy music alone but listening to or performing music, including singing, with others seems to elicit the most profound connection we have to others. We can trace this from our earliest ancestors dancing rhythmically around a fire to singing along to the Last Night of the Proms or belting a rock hymn in a stadium. This social connection has also strong relevance for music as a therapy for dementia. But I am getting ahead of myself.
If there is one component that music elicits in us, it is emotion. Now emotion we often consider to be a feeling of joy, sadness, jealousy, anger and so forth but in fact, it is a bit more complicated. In terms of music, we can distinguish five different components of emotion which can be elicited by music:
1) Cognitive component: This is somewhat of a cerebral component, as it is our appreciation of a piece of music that can also raise positive or negative emotions (“I always loved/hated this piece”).
2) Motivational component: Music and in particular the beat can induce strong action tendencies. For example, we feel the urge to clap along to certain pieces or drumming our fingers on a table or even stomping our feet. In some cases, it even motivates us to dance, even though we may be not much of a dancing person, as anyone can attest who ever attended a ceilidh. We are literally ‘swept away’ by the music and cannot resist joining in – the urge is simply too strong.
3) Physiological component: Music can also influence our body’s physiology, making us more relaxed or aroused. Just think of the music piped through loudspeakers in shops, which is made us feel relaxed and spend therefore more time (and money) in the shop. On the opposite spectrum are the songs belted out at political conventions/party rallies which are meant to arouse us and get us going. Think again of the beats resembling our heart rate. If we want to relax people, we should play music close to their resting heart rate but if we want to arouse people we might want to play a faster beat which actually increases our heart rate. Even if we know all of this, it is hard to suppress tapping along to a great song, showing how the physiological component is largely subconscious with us having little control over it. Blast you Muzak!
4) Expression component: This component is more about the expression of our emotions while listening to music. We simply cannot help smiling at a song that reminds us of a good time or even crying to music that invokes sad memories. Admittedly the latter is rarer but feeling good after a song, is such a common phenomenon that it is no wonder the air- and internet-wave are full of best-of songs from the decades as the majority of people will have some memories associated with those songs.
5) Subjective feeling component: I guess the name gives us away from that this is much more about our subjective experience of music. The above components might be shared between many different people but the subjective component reflects more how a specific piece of music ‘speaks’ to us as an individual and which emotion it can elicit.
Now, these 5 emotion components relevant to music are somewhat arbitrary and of course, overlap as well. For example, we might be subjectively moved by a piece while at the same time being aroused and want to join in the dancing. The other interesting aspect of these components is that memory plays a key role in eliciting those emotions. If we cannot remember occasions in which certain songs remind us, how can we be moved by them emotionally? It is a relevant question for dementia to which we will come back below. But first, we need to understand which brain areas are relevant for music, as this will also be important for understanding how it can trigger emotions and memories in dementia with music.
Brain regions involved
Since music can elicit so many emotional and memory response, it should maybe not come as a surprise that there are a variety of brain areas involved in music processing in the brain. Of course, the first step is to get the auditory signals from our ears into our brain, which is done by the fittingly named ‘auditory cortex’, a superficial brain region lying just above our ears on each side of the head. Similar to visual input, the brain has to re-assemble the auditory information received from the ears (or more precisely, the cochlea of our inner ear which converts the sounds waves into electrical signals). The auditory cortex sends then processed auditory information to more specific brain areas for further analyses. For example, speech-related sounds are processed in language-specific brain areas while music is processed in a variety of brain areas. I am being deliberately vague with saying ‘a variety of brain areas’ since music has so many components, not only beat and melody but also emotion and memory, that it is processed across many different brain areas. Indeed, looking at the meta-analyses of brain imaging studies shows a plethora of brain areas, which I do not want to rattle down. Instead, let’s focus on a dominant model of music processing in the brain the so-called “‘Quartet Theory of Human Emotions”. This clever wordplay already highlights that four brain regions are highly relevant for the processing of the musical emotional components we explored above: 1) the brainstem, 2) the diencephalon, 3) the hippocampus and 4) the orbitofrontal cortex (see figure below).
Without going into too much detail, the brainstem and the diencephalon are very deep regions in the brain, responsible for many of our subconscious brain functions, such as heart rate, breathing, satiety, thirst and so on. However, they are also very important in our arousal and relaxation, so that if they get stimulated, we can get more easily aroused or relaxed and since the brain regions responsible for heart rate and breathing are close by it can even affect our heart rates. Think again back to how the musical beat close to our heart rate can influence whether we are relaxed or aroused. Further, those brain regions can often influence our motivational state. It makes therefore sense that the physiological, expression and motivational components of music influence these brain regions. In most dementias, these brain regions remain fairly intact until the very late stages of the disease, which means that musical stimulation via these brain areas remains a very feasible avenue even in the latter stages of dementia.
The orbitofrontal cortex is part of a larger ‘reward network’ in the brain, which lets us evaluate if an experience is pleasurable or not, including music. It clearly makes sense that this network is involved in the cognitive and subjective feeling components of our musical emotions as we can ‘feel’ the pleasure the music brings to us, as a reward. The orbitofrontal cortex is similar to the deeper brain regions, less affected in Alzheimer’s disease at the beginning of the disease, although it can be severely affected in other types of dementia such as frontotemporal dementia, affecting their reward perception.
Finally, a hippocampus-centred network is involved in our music listening. The hippocampus (Latin for ‘Seahorse’) is a key component of our memory systems for personal experiences. Since so much music is related to specific events, it again makes sense that the hippocampus is activated during our music listening. Not only can it retrieve memories elicited by the memories but also create new memories for new songs we might be listening to.
That’s all very well, but how is this all relevant for music and dementia?
We have now all the key elements to understand how potentially music can make people with dementia to ‘come alive’ and even elicit memories thought to be long lost.
How is that?
Music and memory
We now know that music is widely distributed across many brain areas and has very different emotional components. This wide distribution allows our brain to engage us with music on multiple levels. The relevant aspect for brain disease such as dementia is that even if certain brain areas are affected by the disease, the widespread functions of music still allow eliciting responses and emotion in people with dementia, or other brain diseases.
For example, the physiological response from music, which is mediated via the brainstem/diencephalon, can be still elicited in dementia until the very later stages of the disease, since these brain areas are – usually – the least affected by the disease. It explains, why there are so many astonishing videos on the internet showing people with advanced dementia who are completely passive at the beginning of the video but once the music becomes highly active again, even getting up or dancing around. It is wonderful to see this happening but after reading this article, we should not be astonished by this, since we now know that the arousal brain areas in the brainstem/diencephalon are still intact in people with advanced dementia and could be triggered by music that was played to them.
The other astonishing videos are when people with dementia while listening to music can ‘suddenly’ remember the words to the songs, while they seemingly cannot remember anything else. There is a common misconception that once people with dementia cannot recall memories that those memories are ‘lost’. But in fact, there is quite a lot of evidence that the memories remain in the brain but dementias such as Alzheimer’s disease affect more the access to those memories. The key component in this regards is the hippocampus as a brain structure. We should see the hippocampus as an indexing mechanism, which lays down indices for memories stored in different parts of the brain. During Alzheimer’s disease, the hippocampus gets affected by the accumulating proteins, which means that the indices are not laid down anymore properly, causing memories not to be stored at all or incompletely and the retrieval of memories via the indices is also affected. This might look on the outside as if the memories are forever lost, but in fact, the problem is more of accessing the memories. Access to ‘certain’ memories can often still be elicited, even in the latter stages of the disease.
What are those ‘certain’ memories?
One type of memory which remains accessible is older memories since they were laid down before the disease took hold of the hippocampus. It makes the person with dementia appear to be ‘living in the past’ as their older memories remain intact while more recent memories are not there at all or only the gist of it is remembered. The reason for the older memories to remain intact for longer is that their indices are much stronger than the ones of the recent memories. Older memories are just much longer in our brain and have been retrieved many more times, hence the indices for those older memories are much stronger. The other type of memories which remain accessible, as they have stronger memory indices are emotional memories. Emotional experiences are often of great importance to us and hence we want to remember them in as much detail and as long as possible.
It should now make sense why music is so powerful in eliciting memories in people with dementia, even in quite advanced stages. In particular songs from long ago which have strong emotional associations should elicit emotions in people with advanced dementia. It is a sign that the song triggered an emotional memory in the person with dementia, which was thought long lost. Due to the multi-faceted nature of music, which taps into our conscious and subconscious emotional components, it seems the ideal memory trigger for people with dementia. Indeed, the astonishing transformation of people with dementia through music has led to a plethora of music apps/stations and even therapies to improve their well-being and quality of life.
What is the scientific evidence that music as therapy can improve the well-being and quality of life in people with dementia?
Music therapy in dementia
Overall, there is good evidence that music therapy reduces significantly anxiety, depression and apathy (a loss of motivation) in people with dementia. This mirrors what anecdotal evidence is suggesting as well. Scientific evidence for a reduction in agitation, improvement in cognitive function and everyday functioning has been more mixed, with some studies showing positive evidence while others show no or little evidence. For now, we have to say the jury is still out for those factors. One complicating factor, which has been noted throughout the scientific literature is that there is little standardisation of music therapy, which can make it very difficult to determine whether the measured effects were really due to the ‘music therapy’. From the above, it makes sense to establish personalised playlists, since not everyone will have certain emotional memories with certain songs and indeed that has been already happening. However, the more subconscious relaxation and arousal component has been far less explored, even though we now know that it can make people ‘come alive again’. Since music has such an enormously beneficial impact on dementia, there is clearly an urgent need to investigate and standardise music therapy further, so that more people can benefit from its positive aspects.
In summary, music engages our brain on multiple conscious and subconscious levels, which makes an ideal therapeutical approach for brain disease such as dementia. The multi-faceted angles allow for people to overcome the challenges of their brain diseases, which in turn reduces their anxiety, depression and apathy symptoms. While there is anecdotal evidence that the quality of life is also improved in people with dementia, the exact scientific evidence is still outstanding for this point. Still, the benefits clearly show that there is no harm in enhancing our lives with music, regardless of whether we have dementia or not.
Get those tunes playing!
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