Monthly Archives: July 2012

It’s a bit like that science fiction movie with the blonde children

In the course of my normal internet and print reading, I’ve come across a photo of an accomplished lady who has a career that encompasses technology, science and narratives. She has straight pale blonde hair and blue eyes. She’s clearly very smart. She has a surname that originated from one of those nice, neat little Baltic nations. She is also a dead-ringer for Jean (not her real name).

Don’t forget the parietal lobe – the connections are interesting

If you have been reading this blog for a long time you’d know I’ve been trying to figure out which parts of my brain are responsible for my synaesthesia and related experiences. I’ve found that the right fusiform gyrus is a part of the brain that comes up over and over again, in relation to synaesthesia and also face recognition I experience many types of synaesthesia and also have achieved scores in face recognition tests consistent with being a super-recognizer, so this combination seems significant, and despite a lack of any evidence from other case studies linking synaesthesia with superior ability in face recognition, I still think it is a possible relationship that should be scientifically investigated, especially in light of a pattern of associations which I believe suggests that synaesthesia might be a neuropsychological condition that could be seen as the opposite of Benson’s syndrome, which is a type of dementia that involves a loss of visual perception, apparently including a loss of face recognition ability. While synesthesia is generally an inborn developmental condition, and Benson’s or PCA a neurodegenerative condition with a typical onset late in life, I’ve still got to wonder whether inborn factors contribute towards Benson’s. While Benson’s is considered to be a variant of Alzheimer’s, I don’t think anyone knows why it causes deterioration in different areas of the brain as are affected by Alzheimer’s, apparently the same parts of the brain (at the rear) that appear to be enhanced or hyperactive in my brain, and I also doubt that anyone knows why Benson’s has an onset earlier than Alzheimer’s disease. I’m sceptical of the idea that Benson’s is just Alzheimer’s of the back-end of the brain. I suspect that immune system elements microglia and complement might be central to an explanation for Benson’s syndrome. Reading Dr B. Croisile’s paper about Benson’s I’m struck by the many very strange effects of Benson’s on perception, and I wonder at the ways in which a study of it might inform science about  the workings of the brain. I think it is at least as interesting as synaesthesia, which attracts a lot of attention from researchers. Apparently people with Benson’s cannot imitate movements. Does this mean that the mirror-neuron system which so many neuroscientists have gotten so excited about is located at the rear of the brain? I note that the inferior parietal cortex is one of the parts of the brain that are thought to house mirror neurons.

When I set out to write this post I had actually planned to write about a fairly recent review journal paper focusing on recent research about the most common and well-known types of synaesthesia: coloured hearing, coloured graphemes and time units in space synaesthesia. I really like the paper cited below by Professor Karsten Specht from the University of Bergen in Norway, and I’d recommend it to anyone who wants to learn about the latest knowledge about synaesthesia from just one paper. I only have a couple of gripes about he paper. I wouldn’t describe synaesthesia as “rare” as Specht does. Ward, Sagiv and Butterworth wrote in 2009 that around 12% of the population have number forms, and that estimate doesn’t surprise me. Synaesthesia in general can’t be rare if it includes one type that isn’t rare. Time-space synaesthesia or number forms is one type of synaesthesia which the synaesthete can have but not suspect that it is synesthesia, or anything out of the ordinary, so I’d guess it could be very much under-reported and under-estimated. My other gripe with Professor Specht’s paper is this bit; “In recent years, several studies have attempted to investigate whether synaesthesia is primarily a perceptual or conceptual phenomenon.” I think Specht is here presenting the reader with a false dichotomy. In some of the types of synaesthesia and related phenomena which I experience sensory perception, memory and conceptual thinking are connected with synaesthesthetic linkages, so I doubt that there is much point in trying to characterise synaesthesia as one or another type of phenomenon. I was very excited when I read the book Beyond Human Nature by philosopher Jesse Prinz. Professor Prinz argued that we think in mental images rather than in language. He wrote that “It used to be thought that the back part of the brain is used for perceiving and the front is used for thinking. But we now know that the back part of the brain, where most of the senses are located, is very active when people think. Moreover, we know that the front part of the brain does not work on its own, but rather coordinates and reactivates sensory patterns in the back. Recent evidence from Linda Chao and Alex Martin has shown that reading activates the same areas as looking at pictures, suggesting that we visualize what we read.” In a post that I wrote a while ago I described involuntarily “seeing” in my mind’s eye visual images of landscapes and building interiors from imagination and memory while listening to an autobiographical audio-book. I thought it was probably related to synaesthesia, but it appears that everyone’s brain illustrates text with images when reading. Perhaps synaesthetes do this to a greater degree or in a way that is more available to conscious awareness.

Anyway, back to Specht’s paper. Having read it I now suspect that the parts of my brain that are bigger or better connected or more active or something are: the right fusiform gyrus (including the FFA), the left parietal lobe including the left intraparietal sulcus, the right inferior parietal lobe, the hippocampus (I’m sure is involved with IMLM) and the parahippocampal gyrus. I’d guess that these are the places where interesting things are happening. It appears that the role of the parietal lobe in synaesthesia has been understated in the past. It is now thought that synaesthesia does not solely involve the cross-activation of two different sensory areas (as if it was ever that simple!), but it also requires a “binding” process to happen in the parietal lobe. There is no underestimating the importance of this binding.

If you are as interested in synaesthesia and bits of the brain as I am, you might also like to read a much longer journal paper by Rouw, Scholte and Colizoli that was published last year. It is available in full text at no cost, but I don’t think it covers non-colour types of synaesthesia. Details can be found below. One part of the parietal lobe mentioned in that paper, which is cited by a few studies as involved with synaesthesia is the inferior parietal lobule (IPL, Brodmann areas 39 and 40). It is also known as Geschwind’s territory because the neurologist Geschwind predicted in the 1960s that the parietal lobe played a role in language, and was proven right when the IPL was found to include a second connection between Broca’s area and Wernicke’s area, which are of central importance in language. The IPL is very interesting as a part of the brain involved in synaesthesia because according to a 2004 article in New Scientist magazine the IPL matures at a late age, between the ages of five and seven years, which just happens to be time in life when children typically learn the ability to read and write, and it is also the age range in which some children develop grapheme-colour synaesthesia. I find this very interesting because in my family we have at least three closely related grapheme-colour synaesthetes who are unusually high achievers in reading and writing in testing and academic achievement. Two of these synaesthetes were early readers and also talented at language learning. What’s the betting that some gene that alters the development of the IPL is behind this? The author of the most interesting little science magazine article that brought me this news, Alison Motluk, is herself a synaesthete. Is it just a coincidence that a journalist with a well-connected brain has pointed out a number of interestingly related facts that are connected around the conceptual hub of the inferior parietal lobule?

Specht, Karsten Synaesthesia: cross activations, high interconnectivity, and a parietal hub. Translational Neuroscience. Volume 3 Number 1 (2012), 15-21, DOI: 10.2478/s13380-012-0007-z
http://www.springerlink.com/content/512306132j162437/

Croisile, Bernard Benson’s syndrome or Posterior Cortical Atrophy. Orphanet. September 2004. http://www.orpha.net/data/patho/GB/uk-Benson.pdf

Ward, Jamie, Sagiv, Noam and Butterworth, Brian The impact of visuo-spatial number forms on simple arithmetic. Cortex. Volume 45 Issue 10Pages 1261-1265 (November 2009). http://www.cortexjournal.net/article/S0010-9452(09)00213-5/abstract

Rouw, Romke, Scholte, H. Steven, Colizoli, Olympia Brain areas involved in synaesthesia: A review. Journal of Neuropsychology. Special Issue: Synaesthesia. September 2011 Volume 5 Issue 2 p.214-242. Article first published online: 16 SEP 2011 DOI: 10.1111/j.1748-6653.2011.02006.x  http://onlinelibrary.wiley.com/doi/10.1111/j.1748-6653.2011.02006.x/full

Motluk, Alison Two links good for kids’ language comphrehension. New Scientist. Issue 2478. December 18th 2004. p.12. http://www.newscientist.com/article/mg18424784.300-second-link-discovered-in-human-language-circuit.html

Some unusual types of synaesthesia which I have experienced only rarely or during a limited period in my life

Coloured flavour / Coloured smell synaesthesia / taste – colour synaesthesia

Most taste experiences are an amalgam of taste sensation on the tongue and smell sensations in the nose, so to be completely correct this isn’t purely triggered by a taste, smell is certainly an element, but in plain-language terms, the trigger is a novel taste or flavour.

This only happens during the unusual situation in which I am at a public swimming pool or some other place where I have the smell of chlorine in my nose and I am also drinking iced coffee, and there is some kind of chemical reaction between the chlorine and the coffee in my mouth/nose resulting in a peculiar smell/taste that is somewhat like a floral or perfume smell. It is a black-coloured smell/taste. Sometimes the image of a black-coloured flower flashes into my mind, shaped something like a simple lily. Upon reflection I believe that it is the surprise or novelty of the modification of the usual flavour of iced coffee that is the synaesthesia trigger or inducer. Often as an afterthought after this experience I realise that the normal taste of iced coffee is a brown-coloured taste, but I never notice this as it is such an ordinary thing that it kind of stays below the level of consciousness.

Viewed facial expression – flavour synaesthesia

It is hard to know for sure what the exact trigger was. It was only ever triggered by one person when they were preschooler-aged, giving me one of those big hugs that parents get when they pick a young child up at the end of a kindy day, the kind of hug that has a run-up with open arms, involving an incredibly cute young child wearing a huge smile, not your average hug situation at all. What was the exact trigger? The emotion? The situation? The hug? The child? The time in our lives? I think it was the image of that incredibly cute individual young child’s face with a big smile on it, but I’m not really sure. I have a number of kids. This experience only ever happened in relation to one child, and I believe this is because of facial appearance. The period in time when this used to happen was many years before I had ever heard about the concept of synaesthesia, and I had no idea why I was experiencing a pleasant phantom taste in my mouth in this type of situation, and I thought it was most odd, but also rather nice. Sometimes this very rare experience included a kind of other-worldly feeling, like a very short visit to a rather nice alternative reality. It has been many years since I had this experience and I don’t expect I will ever experience it again. Why do children have to grow up?

The Strange Phenomenon or image of one person’s face evoked by viewing another’s face in a synaesthesia process

Described in great detail here: https://superrecognizer.wordpress.com/2010/12/04/a-most-peculiar-experience/

Smell/taste – concept synaesthesia

Two different pleasant and specific sensory experiences have triggered the same subtle and rather vague conceptual experience. I’m not completely sure what the synaesthesia trigger (inducer) and the synaesthesia anomalous experience (concurrent) are. It’s a vague and subtle and quite mysterious thing. A couple of years ago I started drinking tea more than I had been in the past. It was Twinings tea, because that was the only brand on the market offering a range of different types of teas, genuine old tea varieties made from different types of tea leaves from different countries, not the modern ridiculous teas with synthetic fruity flavouring added. I had been drinking some of the more popular tea varieties like the breakfast teas and Orange Pekoe, and then I tried out Prince of Wales tea, which is a black tea with a quite different and a much more refined and subtle taste. For a short period of time, perhaps a few weeks, my first sip of Prince of Wales tea would reliably trigger an idea that would spontaneously jump into my head, a strange nostalgic feeling that is hard to describe. The  image and the smell of old, pale-coloured paper notes of currency (which is hard to identify) would come to mind, along with ideas of my maternal grandmother, the fine, old French perfume that she wore, finely scented old varieties of roses (which might have once grown in her now-demolished rose garden), an old saying that she used to use “I wouldn’t trade you for all the tea in China”, notions of fine things from the Orient in the “olden days”, the concept of exotic delicacies from foreign lands, and a generally nostalgic feeling of having visited a better world for just a small moment.

Upon reflection, I think this very specific variety of tea (Twinings Russian Caravan tea has a very similar taste to the Prince of Wales variety but does not act as a trigger for my synaesthesia) is not the only sensory experience that has triggered this weird nostalgic sensation/concept. Many years ago on a beautiful day I was testing the scents of different varieties of roses at a specialist plant nursery, and I recall that the subtle but beautiful smell of the Buff Beauty variety of rose, a pale yellow-pink hybrid musk rose that was bred in 1939, was unusually evocative, triggering thoughts of pale old paper bank notes and a peculiar sense of nostalgia that seemed to extend beyond my own years on Earth. This interesting experience was not enough to sway my purchasing decision, and I ended up buying a similar variety of hybrid musk rose which had a stronger smell and a prettier colour, but with fairly limited powers of evoking conceptual thinking.

It appears that sadly this is another type of rare synaesthesia which I will never be able to experience again, because a few years ago something changed.  My first sip of Prince of Wales tea no long packs a beautifully subtle punch. It no longer evokes anything but a tea flavour. Perhaps the trigger of the strange experience had actually been the contrast between the taste of this type of tea and the more full-flavoured varieties of tea that I had become accustomed to back then. The trigger might have been the novelty of the new taste of a more refined tea, but I’ve got to wonder why I experienced no synaesthesia triggered by drinking a full-flavoured tea after drinking Prince of Wales for a while. I’m inclined to think that the quality of the Prince of Wales variety of Twinings tea dropped off or changed, causing the end of the odd phenomenon. I’ve tried countless other varieties of tea to see if they evoke that odd experience to no avail, and even though boutique tea shops are popping up all over Perth stocking all manner of horrible brews, none of them carry any Prince of Wales variety tea. I give up! I just give up!

Touch – emotion synaesthesia

When I was a teenager I had the habit of wearing a favourite item of clothing almost non-stop till it fell apart. I guess that as a result of this practice, by brain built up a substantial touch-memory of how my favourite garments felt when I wore them, an unusual type of memory which I possibly don’t possess these days and which most people never possess.  Back in those days I found that something weird would happen when I was in the change room of a department store or boutique trying on new clothes. As I put on the new garment I would feel a spontaneous, involuntary, unexpected, weird, sudden, dramatic wave of something like a hybrid of an emotion and a bodily sensation. It was something like a shudder. Even the emotion itself was hybrid-like and hard to describe, perhaps dread, perhaps intense homesickness, maybe it was a sense of adventure, or maybe loneliness. Weird! At the time I assumed that this thing happened because it violated my unconscious expectation of the familiar touch-memory of my old, well-worn clothes. As is often the case with types of synaesthesia that I rarely experience, sensory novelty or change appears to be the real trigger or the synaesthesia inducer. I’m not sure how often or for what period of time I would have this odd experience while trying on new clothes, but I am sure it was limited to my teenage and possibly early adult years. It is no longer experienced, presumably because I no longer in the habit of wearing a favourite items of clothing constantly, or conceivably it could be because I have less sensitive senses these days.

Added an afterthought to a recent post

Did the police and everyone else get it wrong? http://wp.me/p1dnAW-qH

Another aspect of interest in the above linked post is one comment in it, which is off the topic of the post, but I don’t mind. It is a comment from Michael who wrote that he experiences a type of coloured face / aura synaesthesia that involves emotions, similar to the other fascinating cases described in the synesthesia study by Spanish researchers published this March in the journal Consciousness and Cognition, which I wrote about in a post at this blog, and would like to find the time to write more about, but probably wont.

Other cases of synaesthesia involving face perception – I’m certainly not the only one.  https://superrecognizer.wordpress.com/2012/05/06/other-cases-of-synaesthesia-involving-face-perception-im-certainly-not-the-only-one/

Time-blind, face-blind, smell-impaired, touch-disabled, dyslexic – there’s an amazing variety of disabilities of perception

It goes to show how common synaesthesia is, when a host of a radio show episode about super-recognition that I have referred to previously at this blog just happens to be a synaesthete. I know this because she was on the radio yesterday morning promoting her latest pop psychology book, which looks like it will be an interesting read. The BBC broadcaster, author and psychologist Claudia Hammond experiences the days of the week as having their own colours and insists that Monday is a pillar-box red, an assertion which to my mind does not seem odd but simply incorrect. Sure enough, the letter M is red (but certainly not pillar-box red) but surely it is plain to anyone that Mondays are white? Hammond and the cheery radio show host Natasha Mitchell also discussed other varieties of synaesthesia: time-space synaesthesia and mental number lines. Hammond’s new book is about the perception of time and it looks like it will include discussion of disability in perceiving time, and will also probably cover time-space synaesthesia.

I’ve had a look on the internet for more info about Hammond’s new book titled Time Warped, and while reading an excerpt of the book at Amazon I’ve found yet another obscure and highly specialized type of disability of perception, an inability to sense the passing of time, a condition which appears to be so obscure that it still has no name. Hammond gives a fascinating description of Eleanor, who has a deficit in sensing the passing of time that goes way beyond poor time management skills, and also has dyslexia, probably not coincidentally.

In this blog which is primarily about exploring possible links between synaesthesia and high ability in face perception and also an exploration of the opposite condition of prosopagnosia or face-blindness, I have discovered that prosopagnosia is by no means the only highly specialized disability of perception. Prosopagnosia is only one of a range of visual agnosias, which is a sub-set of the agnosias, which are a huge range of brain-based diabilities (not associated with memory loss) in recognizing specific things such as people, voices, shapes, smells, time, faces, colours, classes of objects, images of objects, pain, speech, text, body language, intonation, etc. Prosopagnosia appears to be often associated with another agnosia which is a disability in establishing visual memories of scenes, including things like streetscapes and buildings, and it seems possible that it could be linked with other better-known disabilities such as dyslexia. Each case is different, and prosopagnosia and other agnosias can be caused by genetics or damage in the brain, so one should not make sweeping generalizations. There appears to be no standard term or definition of the issue with place memory, with a variety of terms in use. I guess most people would be aware of the sensory and perception disabilities of blindness, deafness, paralysis and dyslexia, but there is also a huge range of other specific disabilities and disorders of perception and understanding, some affecting taste, smell, balance, mathematical and number sense, touch, music and tone perception. Many of these can be naturally-occuring or the result of brain injury. New Scientist magazine reported a while ago that a deficit in the sense of touch appears to be genetically linked with deafness. Scientists are only now beginning to establish knowledge about the nature of these disabilities and possible relationships between them. On top of this bewildering range of agnosias and disabilities are sensory disorders and visual disturbances that can be asociated with mental illness or are similar to mental illness. And on top of that are sensory-cognitive experiences that are simply odd or unusual but not disordered or a deficit. Synaesthesia fits into this category, of which there are more types than any sensible person would claim to know.

I find these things endlessly fascinating because it gives an insight into the significant fact that there can be many important differences between the way that apparently normal, intelligent people percieve and understand what appear to be simple sensory inputs from the world around us. The more I study this subject, the more I understand that there is nothing simple about perception and the understanding of sensory inputs. This kind of brain-work is hugely complex and it is no wonder that many areas of the brain are involved in this kind of work, and that sensory processing is very much involved in thinking in general. It is impossible to guess how many different ways that the person sitting next to you on the train might differ from you in perception and sensing, and it isn’t only about disability. For many of the agnosias and diabilities of perception and sensing there are conditions that are opposites or give rise to superior abilities that are like opposites. Does the old bloke across the way see violet mauve in his mind’s eye when he hears the train driver sound her horn, because the horn is at a pitch that his mind links with this colour, in an interaction between his perfect pitch and his coloured sound synesthesia? Does the super-recognizer in the carriage feel a tingle of familiarity from looking at two of the faces in the carriage? Is the super-taster still recovering from the second-rate coffee that he paid too much for at a fancy cafe? Is one passenger watching the screen display of info about which station the train is at like a hawk, instead of using her spare time to catch up on some reading, because she was born without any sense of time passing and can’t remotely judge the duration of her planned train journey?

Time warped: changing your perception of time. Life Matters. Radio National. July 2 2012. http://www.abc.net.au/radionational/programs/lifematters/claudia-hammond/4100994

Added to old post

I have just added more text to an old post about sculptures in a park/playground in the Perth suburbs and synaesthesia. I have briefly described some types or nuances of synaesthesia that I experience, which could be things that are new to synaesthesia research. To me they are pretty ordinary experiences.
http://wp.me/p1dnAW-ju

Fascinating stuff!

I believe there might be some very interesting things to be learned about prosopagnosia, super-recognition and types of synaesthesia that I’ve experienced, from the study of cognitive problems experienced by astronauts as the result of weightlessness. Will I find the time in my busy day to write about this? I hope so.