Infected by earworms, what Mozart does for the mind, plus are creativity and delusions linked?
In this episode
Why are song lyrics so easy to memorise?
Professor Ian Cross, Director of the Centre for Science and Music tackled this question! Ian thinks it's due to the structure of poetry and music.
Ian - That gives us a hook to hang the words on. We know that if the words don't match with that temporal structure they can't be the right words. So, it kind of narrows down the problem space, narrows down the search space. Lyrics to a piece of music is probably even more so because there's not only the rhythmic structure, but there's also melodic structure - the tune, the ups and downs, and the pitch that the words accompany. Put all these together, and that gives you a very powerful set of cues that help you remember, much more perfectly than just remembering random stretches of takes for speech.
Hannah - And Carly Pease has been in touch asking, how does perfect pitch work and how come some people have it and others don't? Is it something that you can learn?
Ian - Well, we tend to prefer to see absolute pitch rather than perfect pitch because it's not perfect. It is absolute. That is when you hear a note, you know it's, "Oh, that's an E, that's a B, whatever." Absolute pitch is something you probably do learn or perhaps better unlearn. It's quite likely that in early infancy, we're attuned to absolute pitch as a useful way of distinguishing events in the world. But as we develop, as we grow, it becomes less and less useful and the frequency relationship in variance - in musical intervals if you like become more significant as ways of differentiating between events in the world than the absolute pitches at which those frequency intervals occur. However, some people do retain and develop their capacity to identify absolute pitches absolutely. Typically, if they start learning piano age 4 or 5, there was an interesting study done a few years ago where the incidence of absolute pitch in the Japanese conservatoire and in Greek conservatoire was compared. The incidence of absolute pitch in the Greek conservatoire was about 3%. 3% of the student had absolute pitch, in the Japanese conservatory, 57%. Why the difference? Well, the research will look quite closely at a number of things and suggested - actually, it was a question of the age at which people started learning instruments, the likelihood that they were learning piano first, and the amount of practice that they put in, the amount of hours. The Greeks apparently seem to be much more laid back, "Whatever!" Whereas the Japanese were, "Hmm, must do this, must do my 8 hours a day." There was a researcher called Paul Brady who tried to learn absolute pitch, gave himself absolute pitch. In his mid-40s I think and he eventually did learn to be able to identify pitches absolutely, but it was always effortful for him, and it was much, much slower than someone who has developed absolute pitch "naturally".
Hannah - Thank you, Professor Ian Cross from Cambridge University and he'll be back again later in the show to tackle some more of your questions.
04:32 - Contagious earworms!
Contagious earworms!
with Dr Lauren Stuart from Goldsmiths at the University of London
And what exactly is happening in the brain when you listen to music that you like? Well last month, published in the Journal Science, Valerie Salimpour and colleagues at McGill University Montreal imaged the brains of volunteers whilst playing them soundbites of music and found that perhaps unsurprisingly, when the participant rated that they liked a particular new tune then a bit of their brain called nucleus accumbens which is buried deep in the brain, lit up with activity. It's involved in reward during addiction, eating and sex.
The response of the nucleus accumbens that could predict whether the people were likely to buy that new piece of music that they haven't heard before, but scientists think that the individual's previous exposure to different environments and different musical scenes might affect those connections which then connect with the nucleus accumbens and drive the reward or pleasure response to the music.
So, we've learned a little bit about what happens when our brain reacts to music that we like, but what about, earworms? So, songs that you don't necessarily like! Why do particular songs get stuck in people's heads? I started by asking a few people what music plagues them.
Male - My current earworm is Tonight's the Kind of Night and that's by a band 
called Noah and the Whale. (Singing)"Tonight's the kind of night when everything could change" and I get this earworm when I'm driving or when I'm walking somewhere because it's quite a good pace for walking and I think as I'm walking, the song goes round and round in my head. (Singing) "Tonight's the kind of night when everything could change".
Male Two - Well, I actually have a different problem because there were these really cliché bits of music like Pachelbel's Canon that you hear all around the place. Whenever I hear it, for about a day afterwards, I just can't get it out of my head.
Female - The most annoying singer currently is Rihanna. I regularly have earworms about her songs. Every once in a while, you have a singer who don't like the tone of their voice, the content of the songs, and there's other ones that always stick with you.
Hannah - To find out about the science behind this phenomena, I spoke to Dr Lauren Stuart from Goldsmiths at the University of London who has been collecting thousands of reports from BBC 6 Music listeners. I started by asking what's the most common earworm?
Lauren - That's the question that we started to ask. Lady Gaga was coughing up quite a bit, but you might well say, well, that's probably because she had a lot of airtime.
Hannah - Yeah, she's being listened to a lot by the listeners and so, of course, it's going to be going around and round, and round.
Lauren - Exactly, but we were interested, are there any structural features of songs that are reported many times that distinguish those tunes. So, we want to say, what are the structural features that are left over, once you've accounted for recently and popularity? We're still in the process of refining a formula, but we can say that actually, many, many songs are reported as earworms. There's only a very small number that are reported a handful of times. So, it seems that the tunes in our heads are quite idiosyncratic.
Hannah - Everyone has their own individual earworm going on, yeah. At the moment, I've got the Beatles' "Here Comes the Sun" going round and round, round, which is lovely.
Lauren - Absolutely.
Hannah - Do you think there's any reason why we have these earworms?
Lauren - So, of all the questions that fascinates the general public in terms of music in the brain and the psychology of music, the question of why we have earworms and whether or not they have a purpose was one that really seem to pop up a lot and nobody was answering it. So, we thought we could try to at least have a go at doing so and it's harder than you might think to start addressing such question because it's a completely subjective phenomenon. All the studies that have been done on earworms have relied on people telling us, "Yeah, I have a tune in my head" but you know, that's very antithetical to how we normally measure things in science. We normally like to have something objective, some proof that there is something going on in the head. Some brain measurement or reaction time or accuracy measure, not just somebody saying, "Yeah, I've got Lady Gaga "Bad Romance" going on in my head". "Have you really? Should we trust you?" But one hypothesis that I'm particularly interested in looking at is whether or not earworms are a kind of unconscious form of self-regulation. So, by that time, I mean, in the same way when we actually choose real music to listen to from our iTunes library perhaps, we can be very deliberate and conscious about the type of music that we pick out to listen to. And it would be very context dependent. It will be very related to current mood, the mood that we would like to be in.
Hannah - Or maybe the people we're around?
Lauren - Yeah, exactly. The situation that you know, are we doing up some boring task at that time or are we doing the household chores, are we having a bath.
Hannah - And do you think that people consciously or subconsciously pick their earworms?
Lauren - Yes. That's exactly where I was going with this.
Hannah - So, I'm picking my "Here Comes the Sun" because the sun has arrived this weekend.
Lauren - Well, yeah. I mean, we have published a paper, looking at the various triggers that seem to precede earworms and there are many of them. The example that you gave, "Here Comes the Sun" is some kind of them in the lyrics has got resonance with some aspect of your environment or your life. But then there are many other triggers as well. So, there could be recent exposure to a particular song. When we have an earworm, it might be that our brain is unconsciously selecting for us a tune that matches our current mood state or perhaps more interestingly, a tune that matches our desired state of mind.
Hannah - So, if you're feeling down, you may pick an earworm that's quite nice and cheery and jolly because you want to be in the good mood?
Lauren - Exactly or for instance, I was getting ready to pick my son up from nursery and I started getting like a nursery rhyme in my head. Now, it's difficult to say whether or not because I'm thinking about him and that's something really closely related to him, or it could be it was serving the function of getting me in a very sort of energetic state of physical arousal.
Hannah - Getting prepared to pick up your son and spend time with him and be energetic?
Lauren - Just run around and play, yes.
Hannah - So, you were priming your mind in some way?
Lauren - Exactly. Some people say, but surely, there can't be any reason for it because you know, I have these really uncool songs. I get Bananarama or Mr. Blobby and that's surely not going to do me any good for my mood or whatever. So, to them, they think, "This is really just irritating." I think that it could be something that's specific to the tempo of these earworm songs that is serving the function of getting you to a particular energy level if you like. From your brain's perspective, it doesn't care about what's cool and what's not cool. It perhaps just selects a tune in the right tempo range to get you into that state. So, it's kind of complicated because it also depends on - you know, some people might have these earworms that are less prone to noticing them. In that case, you could say, well, maybe you don't have to consciously notice them for them to do their job of regulating your energy level. So, these are things that we probably have to think about and factor in as well.
Hannah - So, some people are possibly better at tuning out their earworm?
Lauren - It could be that, yeah. Just as we have to tune out like real music sometimes if we're in public places and there's music that's distracting us from what we're actually doing. So sometimes, yes. Perhaps that also is the case with internally generating music as well.
Hannah - That was Dr. Lauren Stuart from Goldsmiths at the University of London.
Will listening to Mozart make you brainier?
Ian - In 1993, there was an experiment conducted that appeared as a letter to nature and it was an experiment where the bunch of students did visual-spatial intelligence test. Then either sat in a room quietly for 15 minutes or listen to a piece of Mozart for 15 minutes, and then read their visual-spatial intelligence test. And lo and behold! The ones who were in their Mozart listening condition improved their scores by 3 percentage points which is pretty high. So, Mozart makes you smarter? Well actually, that study was then explored and people try to replicate it, and some worked and some didn't. And they tried it with the rats and it seem to work on rats. So, if it worked on rats, it probably wasn't just something to do with Mozart or even music or whatever. And eventually, someone worked out, well, it could be that listening to Mozart is just more interesting or arousing than sitting in a room doing nothing for 15 minutes. And so, they explored this hypothesis and got people to do either interesting things or boring things between the two versions of intelligence test and when they did interesting things, they got better. When they did boring things, they perform about the same. So, it's not Mozart effect. It's a boring effect. This however didn't stop the governor of Georgia, the US state in the mid-1990s, issuing a governor's edict that every new born infant in the state of Georgia would go home with a CD of Mozart. And I think as far, that's still the case, great for sales of CDs of Mozart, but not much scientific measures.
Hannah - And they certainly haven't been doing any studies on expectant mothers and then following up their children 20 or 30 years later?
Ian - As far as I'm aware, there hasn't been a major impact on the IQ of the students in Georgia, but who knows?
Hannah - Darth Joe has been touch via Twitter saying, "Are humans the only ones that appreciate music or what about other animals such as dolphins or other primates? Do they like music too?"
Ian - Dolphins is a bit difficult. I don't know if anybody has ever asked them really. There has been some stuff done with farm animals study from many years ago as far as I can recall - explored that the difference in weight gain I think it was in pigs when played a music from Radio 1 - this is in the days when Radio 1 played rock music as opposed to Radio 2 - the days when Radio 2 played pop. And they found that the pigs who listened to Radio 2 gained quite a lot of weight. The pigs who listen to Radio 1 however became thin and nervous. That has probably got more to do with the noise levels and the fact that if you listen to a piece of death metal, it sounds more like an animal in pain than does Andy Williams although again, that's perhaps a question of perspective. Trying to get back on to serious track, death metal, if you actually analyse the spectrum, it's very jagged, very noisy. It's quite characteristic of the sort of sound that in the real world would have some biological significance for a whole range of species, indicating that something was in a degree of pain or undergoing some distress, or was being aggressive. All of those possible attributes would be likely to raise the arousal level, raise the stress level of the individual who's hearing the signal. Whereas Andy Williams, not much stress unless you have a loud music.
Hannah - Thanks, Ian Cross and if you've got any burning questions about your brain and the nervous system, you can just email them to neuroscience@thenakedscientists.com, you can tweet us @nakedneuroscience, or you can post on our Facebook page, and we'll do our best to answer them for you. You're listening to the Naked Neuroscience podcast with me Hannah Critchlow brought to you in association with the Wellcome Trust and in partnership with the British Neuroscience Association.
17:20 - Could music help people with stroke?
Could music help people with stroke?
My first paper this month comes from a group of Spanish scientists investigating how music could be of benefit to stroke patients. Julia Amengual and his colleagues at the Cognition and Brain Plasticity Group in Barcelona have been looking at a recently-developed rehabilitation technique called Music-Supported Therapy, which has been designed to help stroke-sufferers with their motor skills, ie increasing their control of the muscles in their arms and fingers.
Stroke is caused by starving the brain of oxygen and is typically the result of 
reduced blood flowing to the brain. The resulting brain damage can have an impact on a variety of brain functions, from deficits in speech and language, to fine motor control. Following a stroke the brain undergoes a prolonged period of re-organisation where parts of the brain attempt to take on the functions of lost parts of the brain, a process often known as cortical plasticity. Previous studies have shown that considerable plasticity is required to regain motor control following stroke but evidence from recent years has suggested that musical training could also have long-term effects on the brain's motor systems.
To test whether a music-based rehabilitation therapy could therefore improve the outcome of stroke patient's motor skills, the researchers of this study assessed Music-Supported Therapy in a group of stroke patients. The therapy involves 20 30-minute music sessions over a four week period. The patients are guided through exercises, playing musical phrases on a keyboard and on an electronic drum pad with their affected hand.
The researchers found that stroke patients undergoing Music-Supported Therapy showed significant improvements in their motor functions, in both the range of their movements and the quality of these movements. Furthermore the scientists also found increased electrical activity in the motor cortex, the part of the brain involved in controlling movements, and a re-organisation of the brain circuits within this area. The study does require some more rigorous controlled repeats but the results seem to show that Music-Supported Therapy is an engaging and fruitful way for stroke patients to retrain their muscles and their brains.
20:24 - How does individuality develop?
How does individuality develop?
Hannah - And now, my paper this month where it's been published in the journal Science and it's really trying to uncover how are our personalities and our individualities shaped.
Well, scientists have been interested in this for a very long time and there's a number of ways that you can start to glean information about it. So, you can look at monozygotic twins that are pretty much identical in terms of their genetic makeup and you can look at twins that have been adopted at birth, and there are cases where there are striking similarities between those adopted monozygotic twins. They may laugh in exactly the same way or have the similar sense of humour, but then conversely, there's also cases of identical twins that have been brought up in the same environment, by the same parents, and yet, they've got very, very different personalities. So, what's going on there?
David - So, even that these people have got the same genetic makeup, they 
may turn out differently and even if they've got the same genetic makeup, they might turn out the same. So, it's very difficult to know what's causing these different behaviour traits. Is it genetics or is it environment?
Hannah - Exactly and so, scientists in this study wanted to get a little bit closer to trying to understand that. So, they looked at mice that were kind of from the same inbred strain. So, they were genetically incredibly similar and they put them all together in a very large cage. They're 40 of these mice that had a very rich environment. So, lots of things for these mice to play with. At the same time, the researchers were able to tag each of these mice with a GPS system so they could monitor how much of the mice run around and whether they were exploring lots of different levels within this massive cage, and they collected this data over 3 months. And then after that 3-month period, they started to peer into the brains of these mice and they looked at a particular area of the brain called the hippocampus which is buried deep in the brain and it's involved in learning and memory, and also navigation. And they looked specifically within the hippocampus and even smaller region called the dentate gyrus which is one of the few areas of the brain where new brain cells are being born throughout life. And it's thought that the birth of these new brain cells is involved in how we can create new memories and also cope with novelty in our environment. And they found that the mice that were in enriched environment had lots of play, had a higher number of nerve cells being born in this dentate gyrus. In fact, it was over twice as many new nerve cells being born within this 3-month extended period. And then they zoomed in even further and they looked at this set of 40 mice that were in the enriched environment.
Now, there's a great degree of variation between those mice that roamed around and explored a lot and then there was some mice that were not fast about exploring. And again, they saw a correlation between the amount of new nerve cells that were being born and the amount at which these mice were roaming around.
Really, the next logical question to me is, what is it about these very genetically similar mice that were kept in the same environment, why did some explore more than others? And that's something that scientists haven't really fully got the grips with. But what the researchers are saying in this paper is that when viewed from an educational and psychological perspective, the results of this experiment suggests that an enriched environment fosters a development of individuality. And it's also maybe important to note that in humans, smaller hippocampi have been found in adults who suffered from neglect or stress as children, and that might be related to this fewer new nerve cells that are born in the dentate gyrus of the hippocampus.
23:44 - Seeing music everywhere
Seeing music everywhere
The last paper is something a little bit different and comes from Oliver Sacks, the neurologist and author of several popular books, including 'The Man Who Mistook His Wife for a Hat', in which he outlines some of his more unusual cases. Publishing a piece recently in the journal Brain, Sacks describes the visual musical hallucinations of 8 people who have contacted him regarding their unusual experiences. These people, suffering from a variety of different medical conditions, from glaucoma to Parkinson's Disease, describe seeing phantom musical staves and notation in the world around them: boldly replacing the text in books, floating in the air and over the walls and even, in one case, becoming the printed border on a bathmat.
Remarkably, although 8 of the 9 people outlined in the article have a musical background, it does not appear to be required to experience these unusual phenomena. Christy C, who reports seeing music under a high fever, describes herself as a non-musician.
But what is occurring in the brain during these experiences. Well the advent of 
accurate brain-scanning technology has allowed us to investigate the neural basis for a variety of functions; reading text for example appears to be associated with a region called the left inferotemporal cortex, but given the differences between text and musical notation, in form and complexity, we can't take for granted that brain areas involved with reading are also employed in the reading of music. Moreover a study from 1992 showed activation of a distinct brain region, the left occiitopareital junction, where the visual cortex at the back of the brain meets the parietal cortex, on the top of the head.
So while the neuroscience behind these highly irregular symptoms is unknown is does give us a sense that our brains are highly impacted by our experiences and interests. The article is wonderfully well written and is packed full of interesting comments about our interpretations of musical text.
I think readers who enjoyed this article might like to take a look at Oliver Sacks' 2007 book Musicophilia: Tales of Music and the Brain, which is a beautifully written account of Sacks' interactions with patients experiencing the power of music. It really highlights the effect that music can have on the brain turn how this influence plays out when our brains are damaged.
26:46 - What gets a researcher up and away?
What gets a researcher up and away?
with Dr Phil Corlett, Yale School of Medicine
Phil - Hi. I'm a Cognitive Neuroscientist and I'm fascinated by the tricks that the brain pulls to help it deal with all of the information coming in from the world, tricks that we can see in action when we observe optical illusions like the rotating hollow mask. The face on the mask rotates and the back end of the hollow mask always seems to point outwards because in our experience, faces point out. These illusion on the lines, how our expectations and our beliefs scope how we see the world.
Sometimes these tricks fail and when they do, people perceive the world in a 
very different way. I'm talking here about patients with psychotic illnesses like Schizophrenia. These patients seem less able to use their past experiences to appropriately constrain what's happening to them currently. A little bit of this can help with creativity, but too much can lead to experiences in beliefs, what we call hallucinations and delusions that aren't shared by other people and then are bizarre, intrusive, and distressing. For example, sometimes patients' brains might predict sounds when there aren't any, manifest those auditory hallucinations.
Other times, their brain might fail to use predictions to screen out the things that the rest of the world would ignore, imbuing those things with a meaning and a significance that patients form delusions in order to explain.
I recently received the International Mental Health Research Organisation Rising Star Award. This organisation funds new research into the causes, treatments, and prevention of mental illness, and the award will help fund a pilot project on the role of potassium channels in how predictions are specified in the brain. Nerve cell membrane excitability is one mechanism through which predictions might be instantiated in the brain and we think that potassium channels might regulate that excitability.
We're going to try to find out whether altering potassium channel function in the brain using a drug called retigabine might help patients with psychosis make better predictions about their world. We hope that this work will inspire new treatments for psychotic illness, treatments that are grounded in cognitive neuroscience.
I'm a Neuroscientist because I'm interested in how the brain forms beliefs, what happens when that belief formation mechanism goes array, and what we might do to try to help.
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