Local brain hyperconnectivity, synaesthesia, autism, music, the temporal lobes and perfect pitch: some interesting reading

Douglas, Ed Perfect pitch. New Scientist Issue 2801 Feb 26th 2011 p. 46-49.

Online title of the article: Finely tuned minds: the secret of perfect pitch. http://www.newscientist.com/issue/2801

This is a most interesting science magazine article about perfect pitch, otherwise known as absolute pitch, the “ability to name or sing any note on demand”, written by someone who himself has perfect pitch. Ed Douglas reports on the findings of studies that have been published in six different science journals, and research scientists mentioned include Daniel Levitin, Sarah Wilson, Elizabeth Theusch, Analabha Basu, Jane Gitschier, Maria Teresa Moreno Sala, Eugenia Costa-Giomi, Patrick Bermudez, Psyche Loui, Diana Deutsch, Luca Tommasi and researchers at the RIKEN Brain Science Institute in Japan.

Douglas explicitly speculates that there could be an association between synaesthesia, autism, and perfect pitch ability, caused by an “excess of wiring in the brain” or hyperconnection. Douglas cites as evidence the study by Psyche Loui and colleagues listed above, and another New Scientist article that reported the interesting “intense world” theory of autism in 2008.

In this article the names of four famous musicians who either had perfect pitch or possibly had it, Beethoven, Ella Fitzgerald, Mozart and Jimi Hendrix are mentioned. The author Ed Douglas does not mention that two of these musicians also experienced coloured music synaesthesia (drug use could have been the cause of Hendrix’s colours). We do not know if Mozart had synaesthesia (my intuition tells me he did), but there has been much speculation over the years that Mozart might have had a range of different neurological peculiarities or disorders. Douglas mentions that Hendrix and Mozart both had an extraordinary savant-like memory for music. Hendrix, Mozart and possibly also Beethoven were left-handed.

Enhanced Cortical Connectivity in Absolute Pitch Musicians: A Model for Local Hyperconnectivity. Psyche Loui, H. Charles Li, Anja Hohmann and Gottfried Schlaug Journal of Cognitive Neuroscience. April 2011, Vol. 23, No. 4, Pages 1015-1026.
(doi: 10.1162/jocn.2010.21500) http://www.mitpressjournals.org/doi/abs/10.1162/jocn.2010.21500

This is one of the studies discussed in the above New Scientist article. Don’t ask me how a journal paper dated “April 2011” can be cited in a science magazine dated “Feb 26th 2011”. The world of science journals is a futuristic world.

Twelve musicians with absolute pitch (AP)/perfect pitch and a matched control group of twelve musicians without perfect pitch were studied. Volume and fibre numbers in some tracts in the left and right hemispheres of the brain were found to be significantly higher in the study subjects who had perfect pitch, but hyperconnectivity was not found all over the place; “Heightened connectivity among AP musicians appears to affect local structures specific to the temporal lobe.” Figure 4 in this paper strikingly shows the difference between the tracts of three groups of study subjects. This paper shows that people with perfect pitch appear to have greater connectivity in the white matter of parts of the temporal lobes that associate and perceive pitch. It looks to me as though greater connectivity in the left hemisphere might be more important regarding perfect pitch. I am not pretending to be a qualified scientist in interpreting this paper.

I believe that greater connectivity in the white matter has been found in grapheme-> colour synaesthetes, in other parts of the brain, so I would not be surprised if music-related synaesthesia might be particularly common in musicians who have perfect pitch. It is no surprise that this paper mentions synaesthesia and has two studies of a synaesthete musician with perfect pitch among its references (see below). Unfortunately synaesthesia is discussed with some negative language in this April 2011 paper; “these disorders” and “abnormal white matter connectivity”. In the discussion of this paper the case is argued that perfect pitch has hyperconnectivity in common with conditions such as synaesthesia, autism and heightened creativity, and the authors identify “increased local connectivity in temporal regions” as a feature that perfect pitch, synesthesia and autism share.

Hänggi Jürgen; Beeli Gian; Oechslin Mathias S; Jäncke Lutz The multiple synaesthete E.S.: neuroanatomical basis of interval-taste and tone-colour synaesthesia. NeuroImage. 2008;43(2):192-203. http://www.ncbi.nlm.nih.gov/pubmed/18692578

This is a journal paper that was mentioned in the 2011 journal paper above. A brain scan study was done comparing E. S., who has perfect pitch and some musical tone-related types of synaesthesia, with other professional musicians and with normal controls. Bilateral areas of hyperconnectivity in the temporal lobes of E. S. were found.

Synaesthesia: when coloured sounds taste sweet. Beeli G, Esslen M, Jäncke L. Nature. 434, 38 (3 March 2005) doi:10.1038/434038a Published online 2 March 2005. http://www.nature.com/nature/journal/v434/n7029/abs/434038a.html

http://www.ncbi.nlm.nih.gov/pubmed/15744291

Another journal article that was mentioned in the 2011 journal paper. Female synaesthete musician E.S. is compared with five non-synaesthete musicians. E.S. experiences flavoured musical tone intervals, which she uses to identify these intervals. It appears that this paper is about the same musician synaesthete with perfect pitch as the one described in the 2008 NeuroImage paper above.

I’m satisfied that there is a real association between synaesthesia and perfect pitch, based on what I have read in the above article and papers, and also based on the fact that perfect pitch seems to be unusually common among musicians who have or had synaesthesia. I believe this association between synaesthesia and perfect pitch is a direct effect of the physical localised hyperconnection within the synesthete brain that gives rise to the synaesthesia and also the increased perception ability, even though I do acknowledge that a type of synaesthesia that gives musical sounds individual colours or flavours could obviously aid in the identification of individual sounds. The question remains though – by what mechanism are the individual sounds identified then each given an identifying taste or colour? Surely a conscious or an unconscious identification of the sounds must precede the allocation of colours to the musical notes.

There is plenty of scientific evidence that various types of synaesthesia give rise to various types of superiority in perception, and it appears that perfect pitch is another example. I do not know if I have any capacity for perfect pitch as I had only the most rudimentary musical education (the same true of my synaesthete close relatives). I’m happy to conclude that simply being synaesthetes makes us especially “at risk” for possessing special powers of perception, including perfect pitch, being a super-recognizer or a superior reader, but it is also clear that specific types of special abilities and specific types of synaesthesia are associated with higher connectivity in specific parts of the brain. So far, my inquiries appear to suggest that the hyperconnectivity in the brains of my kin and I could be limited to the right hemisphere, while perfect pitch might well have as its physical basis higher connectivity in the left, so I guess we could dip out on perfect pitch. If there exists any cost-free test of the capacity for perfect pitch that can be taken by people who do not have musical training, I would love to have a crack at it.

I don’t know about perfect pitch, but I wouldn’t be surprised if there is something a bit atypical about the way our brains process sounds. The enjoyment of music is very important to a number of people in our family, which I’m sure has something to do with the temporal lobes. A lot of the music that we enjoy is sung in non-English languages, languages from all corners of the world. I’m not sure how unusual our taste in music is, but there does seem to be a hunger in our family for listening to exotic phonemes. None of us are language savants like the famous British synaesthete Daniel Tammet, but there is a consistent line of descent in our family of bilingual or multi-lingual people. I also seem to have a thing about unusual voices. I choose to have people in my life who have unusual voices and I love to listen to distinctive singing voices of a range of types. For me, singing voices are easily categorized as interesting or not interesting, and I much prefer the former. The gravel-voiced rap singers Everlast and Tone Loc have interesting voices, and so do all counter-tenors. I recently read an interesting observation about the extraordinary sound of the counter-tenor voice in a newspaper interview article about German counter-tenor Andreas Scholl. “I think these days the audience knows what a countertenor is, but it’s that inability to readily categorise the voice that makes for better communication – you listen with fresh ears, and focus more on the words.” I believe this is an important element of my enjoyment of the voices of countertenors and other singers with interesting voices. The strangeness of the sound draws attention closely, finely, and it also destroys any set of simple musical expectations. I find strange sounds compelling and interesting, and I’m not sure why I find this so very enjoyable, but I do know from experience that when people enjoy doing anything involving thought, they are most likely utilizing some particular area of cognitive strength.

Beth Gibbons from Portishead and Kate Bush are some female singers who have interesting voices. For me, many interesting voices have a colour. Today a rellie and I were having an argument at a supermarket about the colour of the music that we were listening to, as Wuthering Heights by Kate Bush, one of the strangest bits of music to ever hit the top of the charts, was playing on the PA system among the aisles of groceries. Don’t worry about us. We are just a little bit different.

Link between face recognition and synaesthesia becoming obvious – interesting new article about tone-deafness and prosopagnosia in Scientific American magazine

This interesting recent article explains the many similarities between tone-deafness and face-blindness, and how both conditions can be caused by “structural disconnection” rather than damage to the specific parts of the brain that “do” face recognition or musical perception. The distinction between the developmental and congenital forms of these conditions are explained.

You don’t need to be a genius to see that the “structural disconnection” discussed in this article could be seen as the opposite of synaesthesia, but just in case that isn’t completely obvious, synaesthesia is mentioned at the very end of the article, in the notes about the author of this article, who is a scientist at Trinity College in Ireland who studies “the genes involved in wiring the brain and their possible involvement in psychiatric disorders and perceptual conditions, including synaesthesia.” Indeed!

A word of caution – I don’t think there is anything in this article that says that prosopagnosics are more likely to be tone-deaf, or vice versa. Although it would seem a sensible assumption that a group of traits should be found together: good face recognition should be found with intact or great or maybe even excellent ability to consciously comprehend musical notes (perfect pitch or absolute pitch), should be found with synaesthesia, but this is not always the case. Apparently there are synaesthetes who are also very poor at face recognition, and the synaesthete author Vladimir Nabokov has been reported by Oliver Sacks to have possibly had “a profound amusia” (Sacks 2007, 2008 p. 109-110), based on a passage that Nabokov wrote in his memoir Speak, Memory. I think amusia is a fancy word for tone-deafness. In the book Musicophilia Oliver Sacks describes a number of different types of amusia, and interestingly, this prosopangnosic author also describes in his book some episodes of  amusia that he experienced which were a part of the aura of his  migraine headaches. There are so many connections here that it’s almost like looking at a plate of spaghetti!

Are people who have perfect pitch better than average at face recognition? Are super-recognizers synaesthetes? Is perfect pitch unusually common in synaesthetes? Are the opposite deficits associated with each other? Get to work, researchers!

Mitchell, Kevin The Neuroscience of Tone Deafness: The strange connection between people who can’t sing a tune and people who are “face blind”. Scientific American. January 18^th 2011. http://www.scientificamerican.com/article.cfm?id=the-neuroscience-of-tone

Mitchell, K. J. Curiouser and curiouser: genetic disorders of cortical specialization.Current Opinion in Genetics & Development. 2011 Feb 4. [Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/21296568

Sacks, Oliver Musicophilia: tales of music and the brain. Revised and expanded edition. Picador, 2007, 2008.

Tranel, D. Damasio, A. R. Knowledge without awareness: an autonomic index of facial recognition by prosopagnosics. Science. 1985 Jun 21;228(4706):1453-4. http://www.sciencemag.org/content/228/4706/1453.abstract  http://www.ncbi.nlm.nih.gov/pubmed/4012303

 

Postscript 2013 – I’ve had comments from at least one person who is apparently a definite and high-profile super-recognizer to the effect that she is not a synaesthete, so that’s a strike against the idea that supers are synaesthetes. Regardless, I reserve the right to point out that some researchers have found that some study subjects who claim to not have synaesthesia have returned test results that suggest that they are, so it appears to be possible to be a synaesthete and not know it.