Type of music influences exercise performance

If you work out, and you like to listen to music while you work out, you probably have a set of favourite songs or artists that you always listen to when exercising. You might even have a playlist on your iPod called ‘running music,’ ‘lifting tunes,’ or ‘workout beatz.’ Personally, as a heavy metal fan, music from bands like Metallica and Iron Maiden get me focused during a workout. I have a playlist called ‘Heart attack music’ for times that I need the heaviest of the heavy screamer bands to get me pumped up enough to run that extra mile.

But no matter what type of music you prefer, perceived beneficial effects of listening to your favourite music while exercising are probably real. A new study showed that men who cycled at high-intensity while listening to preferred music were able to go a greater distance and had lower ratings of perceived exertion than when they listened to non-preferred music or no music. The study was unfortunately limited in that it only included 15 subjects and all were male, but the findings are quite compelling – subjects were able to cycle for an average of 9.8km when they listened to preferred music as opposed to 7.1km when they listened to non-preferred music (they went 7.7km when listening to no music).

The researchers didn’t report what type of music the subjects preferred, but it is mentioned that faster tempos in songs (a mean rhythm of 117 beats/min) were selected over slower tempos (95 beats/min). These faster tunes were probably chosen to match the elevated heart rates induced by high intensity cycling. However, a fair comparison between ‘preferred’ and ‘non-preferred’ music should control for the effect of tempo, which is a factor that the authors of this study failed to take into account.

Regardless, music can have profound effects on emotion and mood, so it is believable that preferred music can pump us up and encourage physical activity. The authors of this study reason that music can distract an exerciser’s attention from perception of physical sensations, giving rise to feelings of less perceived exertion and less fatigue. Perhaps this is just what it is that keeps us going when listening to our favourite music as opposed to music we’re uninterested in. When music is non-preferred, we try to block it out or ignore it, leading to greater attention to pain and lactic acid build-up in our muscles. When we love the song we’re listening to, and we get really into the intricacies of the beat and melody, we ignore physical pain. If it were possible to put someone in a brain scanner while they exercise and listen to their favourite music, it would be predicted that their pain centres (e.g. the insular cortex) would be less active than during exercise with boring music.

So the lesson is this: bring your iPod to the gym, because listening to Justin Bieber’s latest hit (or other cheesy top 40 songs that are played at most facilities) while exercising can literally be painful.

References:
Nakamura PM, Pereira G, Papini CB, Nakamura FY, & Kokubun E (2010). Effects of preferred and nonpreferred music on continuous cycling exercise performance. Perceptual and motor skills, 110 (1), 257-64 PMID: 20391890

Empathy for pain in doctors versus synesthetes

A common warning given to students interested in a career in medicine is “you better have a tough stomach.” Luckily for physician-wannabes who tense up at the sight of blood, a new study published in NeuroImage suggests that it may be possible to change your brain’s response to watching pain being inflicted on others. The findings are nicely summarized at the BPS Research Digest blog:

Decety's team used electroencephalography (EEG) to monitor the electrical activity arising from the brains of 15 doctors and 15 controls while they looked at dozens of static pictures of people being pricked in various body parts by a needle or prodded by a cotton bud.

When a person looks at someone else in pain, their EEG response typically shows two distinct characteristics: a frontal component after 110ms, which is thought to reflect an automatic burst of empathy, and a more central, parietal component after about 350ms, which reflects a conscious evaluation of what's been seen.

As expected, the control participants showed an enhanced early and later phase EEG response to the needle pictures compared with the cotton bud pictures. The doctors, by contrast, showed no difference in brain response to the two categories of picture.

This means that doctors are essentially the opposite of people who experience synesthesia for pain, a condition I previously wrote about. Synesthesia for pain, the physical experience of pain induced by simply viewing pain in another, has mainly been identified in rare ‘phantom limb’ patients who have had an amputation but still experience sensations in the absent limb. If you can recall, certain areas of the brain are active when pain is felt: some areas involving emotion/affective processing, some areas involving cognition/evaluation, and other areas involving the actual sensation of pain. It is hypothesized that pain synesthetes have overly-sensitive responses to viewing pain in brain regions that are responsible for conscious pain perception.

In contrast, Decety’s new study suggests that doctors have under-active responses in the whole pain matrix. If this under-active response can be acquired by training (e.g. assisting surgeries in medical school), perhaps pain synesthetes could make their empathetic pain experiences go away by repeatedly viewing needles being pressed into others. However, this might not be the best treatment approach as it would probably be exceptionally painful for the synesthete.

Pain synesthesia is acquired (usually after injury/amputation), unlike most other identified forms of synesthesia in which people are supposedly born experiencing numbers as colours or sounds as tastes. Perhaps this means pain synesthesia can be cured as well.

Decety J, Yang CY, & Cheng Y (2010). Physicians down-regulate their pain empathy response: an event-related brain potential study. NeuroImage, 50 (4), 1676-82 PMID: 20080194

Fitzgibbon BM, Giummarra MJ, Georgiou-Karistianis N, Enticott PG, & Bradshaw JL (2010). Shared pain: from empathy to synaesthesia. Neuroscience and biobehavioral reviews, 34 (4), 500-12 PMID: 19857517

Synesthesia of empathy for pain

Synesthesia, the confusion of the senses, has fascinated artists and writers for centuries. However, the first medical description of a synesthete, who experienced “coloured hearing,” was not until 1812.

Now 61 different types of synesthesia have been identified, and new forms continue to regularly pop up in the scientific literature. The most common type is grapheme-colour synesthesia, in which an affected individual experiences letters and numbers as shaded or tinged with colour. There are also such things as “flavour-colour,” “sound-touch,” and “vision-temperature” synesthetes.

Interestingly, many of the more recently identified synesthesias involve emotion, a characteristic that has not traditionally been thought of as a primary “sense” but can be intimately linked to the senses. An example is synesthesia for pain, a condition in which the synesthete has so much empathy for the physical pain in others that the pain is actually experienced when it is observed. This variety of synesthesia was recently reviewed in a paper by Bernadette M. Fitzgibbon and colleagues that describes possible cognitive and neural mechanisms underlying the phenomenon.

Synesthesia for pain has mainly been found in rare phantom limb patients who have had an amputation but still experience sensations in the absent limb. This quality differentiates synesthesia for pain from many other forms of developmental synesthesia in that synesthesia for pain is acquired by experience. Although most of us (hopefully all of us?) feel empathetic towards those suffering from pain, it is thought that some phantom limb patients experience ‘uber-empathy’ for pain due to rewiring and reshaping of their brains.

The neural system that Fitzgibbon’s group mainly discuss as a possible underlying mechanism is of course our great unified theory of neuroscience: the mirror neuron system. Neuroimaging studies of non-synesthetes reveal that certain areas of the brain are active when pain is felt: some areas involving emotion/affective processing, some areas involving cognition/evaluation, and other areas involving the actual sensation of pain. When non-synesthetes observe pain being inflicted on another, the only activated component of the pain matrix is the emotional one. This finding has been interpreted as evidence for a mirror system of empathy (although this is hotly debated in the literature).

So the non-synesthetes feel bad for those experiencing pain but they don’t actual feel that pain (validating the claim “you’ll never understand my pain!!”).

Fitzgibbon’s group hypothesize that pain synesthetes have a “disinihibited” mirror empathy system, such that observation of pain elicits activity in all components of the pain matrix, including the areas involving the sensation of pain. This has not yet been tested, but neuroimaging studies could provide insight to the understanding of synesthesia for pain and possible treatments for this surely gruelling condition (imagine not being able to watch Scarface without feeling as though you are being dismembered by a chainsaw).

Interestingly – although this is pure speculation - further study of non-synesthetes could potentially help us understand synesthesia for pain. We all know people who cringe or feel tingly at the sight of blood. I know that I sometimes get goosebumps when viewing gory scenes in movies. Is this a less severe form of synesthesia for pain? Can these reactions be reduced with certain experiences, such as repeated exposure? Or with brain-altering interventions such as rTMS?

The synesthete may be viewed as abnormal, but perhaps we underestimate the interrelatedness of the senses that exists in us all.

References:

Fitzgibbon BM, Giummarra MJ, Georgiou-Karistianis N, Enticott PG, & Bradshaw JL (2010). Shared pain: from empathy to synaesthesia. Neuroscience and biobehavioral reviews, 34 (4), 500-12 PMID: 19857517