Medical Synesthesia, some people perceive individual symbols, characters, numbers

[fuzzyfelt]

Included in the explanation of my last post here would be evidence of typical early cortical interactions and other cross-modal interactions with feed-forward/feed-back possibilities, not restricted by requirements of sensory deprivation. Included here are more recent papers-

"These findings demonstrate that audiovisual integration and spatial attention jointly interact to influence activity in an extensive network of brain areas, including associative regions, early sensory-specific visual cortex and subcortical structures that together contribute to the perception of a fused audiovisual percept."
http://www.ncbi.nlm.nih.gov/pubmed/19302160 (Oxford Journals Cerebral Cortex)

"Both the topography and timing of these interactions are consistent with multisensory integration early in the cortical processing hierarchy, in brain regions traditionally held to be unisensory.
http://www.ncbi.nlm.nih.gov/pubmed/10978694"

"our study demonstrates that even short-term crossmodal training of novel AV associations results in integration-related cortical plasticity and training-induced congruency effects for artificial AV stimuli in cortical regions especially of the frontal and (to a lesser degree) the temporal lobes, adding novel aspects to the understanding of object-related AV integration in the human brain."
http://ukpmc.ac.uk/classic/articlerender.cgi?artid=1765134#bib11

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WNP-4JJ87X6-1&_user=10&_coverDate=07%2F01%2F2006&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1377795782&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3c090a130b251b32850b7eeb73cb7a00

This may add clarity to the assessment of findings here and to an assessment of speculations concerning different pathways, to explain “higher” and “lower” synaesthete variations which Ramachandran has written of (although there are changes with the new paper that VoM has linked to) generally applied to "associator" and "projector" types.-

“In lower synesthetes, we suggest that crossactivation may occur between adjacent regions of the fusiform gyrus involved in letter recognition and color processing, whereas higher synesthesia may arise from crossactivation in the parietal cortex, particularly in the region of the angular gyrus, the ventral intraparietal area, and the lateral intraparietal area (Hubbard et al., 2005b).
http://www.unicog.org/publications/H...onReview05.pdf “
(Posted in Post #87, and referred to subsequently.)

Here is the latest research on synesthesia.



The link (url) provided above is from the U.S. National Library
of Medicine- National Institutes of Health. You can review from
that website to the right of the page related citations pertaining
to the topic: synesthesia.

This is very interesting, thanks VoM!

Interestingly it only tests the "projectors" (of grapheme-colour) which had been generally termed "lower" synaesthetes. Also interesting that the cross-activation results have been interpreted, following Dehaene, to incorporate hierarchical feature ananlysis processes, and that this is mentioned as occurring at the grapheme level and other levels with excitatory and inhibitory connections, both bottom-up and top-down, and allows for other processes beyond the early cross-activation implicated in the study. The paper states the critical next move is further research of “associator synesthetes” . Also further investigation of “the extent to which the cascaded cross-tuning model of synesthesia applies to other variants of the condition or instances of acquired synesthesia” is required. Interesting that the terms “projector” and “associator” are used here.


Regarding posts about new synaesthetic responses, it is also interesting to note that the paper also mentions that during the component stage of this processing would be the provision of a “putative mechanism for the acquisition of new synesthetic percepts”.

 

[rhody]

Fuzzy,

The paper states the critical next move is further research of “associator synesthetes” . Also further investigation of “the extent to which the cascaded cross-tuning model of synesthesia applies to other variants of the condition or instances of acquired synesthesia” is required. Interesting that the terms “projector” and “associator” are used here.

and

Included in the explanation of my last post here would be evidence of typical early cortical interactions and other cross-modal interactions with feed-forward/feed-back possibilities,

This is very cool stuff, a further parsing, identification, localization, association and labeling of the synesthesia experience. So far, we recognize, upper, lower, projector, associator, implicit (not experienced but showing activation on scans), explicit (experienced and reported), bi-directional, bottom up (perceptual), involvement of early pre-attentive processes, involvement in later attentive processes, possible cross-activation, possible simultaneous activation, possible cross tuning model.

Crap, I gave myself a headache trying to condense it. I am sure I missed some descriptions ! lol. It must be the computer science nerd in me trying to reduce all of it into data structures. You can see what I am trying to do here, take a step back, condense, consolidate.

I have been trying to find accurate graphics and or videos where the "normal" five senses (in a non-senesthetic individual) are thought to be processed for perspective. So far haven't come up with a good set of graphs and/or videos to address this. It would be nice to have for discussion and reference. I will keep looking.

Rhody...

 

[ViewsofMars]

I'll make it fast since I have a project to finish up. I think my last two postings from the previous page provided valuable information, especially "A Whole-Genome Scan and Fine-Mapping Linkage Study of Auditory-Visual Synesthesia Reveals Evidence of Linkage to Chromosomes 2q24, 5q33, 6p12, and 12p12."

Let's look at this scenerio: A child grows up with a parent that has synesthesia. Don't you think the parent has a major influence on how the child perceives his/her environment? I do.

Here are two items for thought which you can explore. I have provided a snippet from each. They are from The National Institute on Deafness and Other Communication Disorders -"The National Institutes of Health—The Nation's Medical Research Agency—includes 27 institutes and centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases." Here are two snippets:

1. "Dr. Patricia K. Kuhl is the William P. and Ruth Gerberding Professor at the University of Washington and the Co-Director of the UW Center for Mind, Brain, and Learning.

"Her research has focused on the study of language and the processing of language by the brain. The work has played a major role in demonstrating how early exposure to language alters the mechanisms of perception. The work has broad implications for critical periods in development, for bilingual education and reading readiness, for early brain development, and for research on computer understanding of spoken language.

"In 1997, Dr. Kuhl was awarded the Silver Medal of the Acoustical Society of America. In 1998, she was elected to the American Academy of Arts and Sciences. And in 1999, she became President of the Acoustical Society of America, and received the University of Washington's Faculty Lectureship Award.

"Dr. Kuhl was one of six scientists invited to the White House in 1997 to make a presentation at President and Mrs. Clinton's Conference on "Early Learning and the Brain." In 2001, she was one of three scientists invited to make a presentation at President and Mrs. Bush's White House Summit on "Early Cognitive Development: Ready to Read, Ready to Learn." Her work has been widely covered by the press. In 1999, she co-authored The Scientist in the Crib: Minds, Brains, and How Children Learn (Morrow Press)."
http://www.nidcd.nih.gov/news/meetings/02/earlylanguage/kuhl.asp

2. “Smounds” Delicious! Smell and Sound Converge in a Little-Known Part of the Brain
"Recent NIDCD-sponsored research shows that cells in a part of the brain called the olfactory tubercle not only discriminate odors -- they also respond to sound. Scientists found that 65 percent of tubercle cells were activated by at least one of five odors. In the same area, about 20 percent of cells were activated by an audio tone. Further, 29 percent of the cells had either an enhanced or suppressed response to different mixes of odors and tones, depending on whether or not the tone was present with the odor. This discovery may provide the first neural evidence for a sensory crossover in the brain where smell and sound converge. It could also help explain clinical reports of sound-smell synesthesia (in which someone “smells” sounds), as well as the ability to relate auditory pitch with specific odors. It also brings to light a relatively unexplored area of the brain that could play a key role in conditions which are accompanied by disorders of sensory processing, such as schizophrenia and Alzheimer’s disease."
http://www.nidcd.nih.gov/news/releases/10/04_19_10.htm

Also, I would like to mention if someone is experiencing symptoms of synesthesia then he/she should consult a doctor.

I realize that I have another topic on another forum. Hope to return to that tomorrow. I have to admit I like it hanging up there.

 

[rhody]

2. “Smounds” Delicious! Smell and Sound Converge in a Little-Known Part of the Brain
"Recent NIDCD-sponsored research shows that cells in a part of the brain called the olfactory tubercle not only discriminate odors -- they also respond to sound. Scientists found that 65 percent of tubercle cells were activated by at least one of five odors. In the same area, about 20 percent of cells were activated by an audio tone. Further, 29 percent of the cells had either an enhanced or suppressed response to different mixes of odors and tones, depending on whether or not the tone was present with the odor. This discovery may provide the first neural evidence for a sensory crossover in the brain where smell and sound converge. It could also help explain clinical reports of sound-smell synesthesia (in which someone “smells” sounds), as well as the ability to relate auditory pitch with specific odors. It also brings to light a relatively unexplored area of the brain that could play a key role in conditions which are accompanied by disorders of sensory processing, such as schizophrenia and Alzheimer’s disease."
http://www.nidcd.nih.gov/news/releases/10/04_19_10.htm

Also, I would like to mention if someone is experiencing symptoms of synesthesia then he/she should consult a doctor.

I realize that I have another topic on another forum. Hope to return to that tomorrow. I have to admit I like it hanging up there.

VOM,

Sound, smell convergence, I understand what you are saying 65% of cells respond to one of 5 odors, and about 1/3rd of those same cells respond to audio, and that 29% had enhanced/suppressed to a mix of smell and sound, which explains the "crossover effect". I fully get that. I have a few questions, first the short finding in the link provided was done by: National Institute on Deafness and Other Communication Disorders (NIDCD), and I believe on a population of test subjects which which may include non-synesthetes and synesthetes alike. How do we know if they were synesthetes or not unless they were tested independently for smell/sound synesthesia before taking the test with results presented here ?

I will answer your question by asking another, you said, " I would like to mention if someone is experiencing symptoms of synesthesia then he/she should consult a doctor." to which I respond, why don't you ask waht or chi meson who are following this thread if they feel they need to see a doctor about their form of synesthesia, and if it in any way inhibits their normal daily lives ?

Lastly, you said, "It also brings to light a relatively unexplored area of the brain that could play a key role in conditions which are accompanied by disorders of sensory processing, such as schizophrenia and Alzheimer’s disease." I don't know how having sound/smell synesthesia correlates to having schizophrenia or alzheimer's disease. I would like to see hard evidence, in the absence of which I would tend to doubt it.

I am not a research scientist but do not believe that the most common forms of synesthesia are "disorders". See quote from zooby in https://www.physicsforums.com/showpost.php?p=2723961&postcount=153" above:

Since synesthesia is not considered to be a pathological condition requiring treatment, I suspect there's probably no urgency about consensus on criteria. Also, it's only been seriously researched for a pretty short time so I'd suppose all the researchers want to keep things open ended until more is known.

Rhody...

 

[Rasalhague]

Hey, cool, a synaesthesia thread!

I have fixed colour associations for letters, numbers, days, months, compass directions and the concepts of left and right. I associate triangles, squares etc. with the colour corresponding to the number of their sides. Like Waht, my A is yellow. My B is a very dark maroon. But we differ on C. Mine is light green.

When I look at a page of writing and I’m not particularly thinking about the individual letters, I don’t see bright and distinct colours superimposed on each letter. But as soon as I let my attention drift from the meaning to the shapes of the letters, I can’t help becoming aware of their “natural” colours: not projected over the real colours in a way that blots out the real colours with imagined ones, but somehow “present together with” the real colours in my mind’s eye, sometimes more strongly present than at other times.

I’m probably not explaining it very well, but I hope my clumsiness of expression doesn’t make it sound too exotic or ineffably mysterious! It’s similar to the way I can picture a scene from memory or imagine something while looking at a real scene without getting the two mixed up, except that the real letters localise the colours somehow, and these colour associations are regular, automatic and spontaneous, compared to the freeform nature of other kinds of associations. If I think of a letter without looking at one, it tends to have its own synaesthetic colour by default, especially if I only think of a fairly abstract idea of the letter without imagining an example of it written down, in which case I can picture it how I choose, although I’ll probably still have a lingering impression of its synaesthetic colour.
For me, yellow is an aspect or attribute of A, part of its nature, and a blue A is an A in disguise! An A in drag?! When I think of the idea now, I have to make a conscious effort to banish the impression of yellow, otherwise saying “a blue A” creates a similar visual impression to “a blue yellow”--I see both colours.

If I need two Greek letters to represent angles, I prefer not to use the traditional theta and phi, as these are both a smoky blue colour, albeit theta a little lighter than the pigeon-blue phi. Alpha and beta, which--like most of the Greek alphabet--have the same colours as their Roman counterparts make a much better contrast. (I should say my first language is English.) A while ago I watched a video--The Mechanical Universe?--that showed electrons as blue and protons as red, the opposite of the colours I associate with the letters E and P. I found this mildly distracting; it meant I had to concentrate slightly harder. It just felt like they were the “wrong” colours. Other than that sort of thing, it’s no trouble.
These colour associations can be handy for recalling numbers or letters, although occasionally if I’m trying to remember a name, say, I might guess it begins with a K when really it begins with T, which are slightly different shades of dark green. “Oh, T,” I think when I find out, “well, I knew it was something green...”

*

My first memory of these associations is from when I was about six and writing on the cover of a school project, being careful to use the right coloured crayon, or the best match, for each letter. I didn’t think there was anything exceptional about this. I didn’t think much about it, and it wasn’t till I was 16 that it occurred to me to ask whether other people had a similar experience. My siblings do. My parents don’t. My siblings have different associations for letters, numbers etc. to me. I first heard the word synaesthesia when I was 19. I never knew there was a word for it till then.

I haven’t followed up on many of the links yet, but I was particularly intrigued by the abstract of Simner et al. (2008) ‘Non-random associations of graphemes to colours in synaesthetic and non-synaesthetic populations’, Cognitive Neuropsychology 22:8 [ http://www.informaworld.com/smpp/content~db=all?content=10.1080/02643290500200122
]. One of the first things I did when I got to thinking about these associations, was to collect lists from people of their colour associations, and the few I got seemed pretty random on casual inspection. I don’t think I really realized, at the time, that not everyone has a special fixed set of associations. I just assumed at first that everyone had it, more or less--which undermined the exercise a bit.

*

I have strong individual colour associations for each of the single digits, and ten is a clear amber colour, eleven is white like 1, and 12 is a paler, more muted blue than two. Beyond that, the colour of the number depends on those of the digits it’s made of. I was intrigued by the mention from Rhody’s anonymous correspondent in #175 of “letter/number-color-gender” as I also think of numbers as having gender. Some are more sharply distinguished in this way than others. By default, I think of odd numbers as female, but there are some exceptions that are male, and some that could be either. (I’m male myself.) When I was 7 or 8, I used to draw comics in which all the characters were numbers and had their own personalities.

Sadly I’m not aware of any convenient encoding of sophisticated mathematical relationships in my colours for numbers, such as Daniel Tammet describes. I don’t have any special connection such as Waht mentioned between numbers and their squares. When I read StarkRG’s comments on the first page of this thread about adding colours, I was all ready to say it didn’t work like that for me, but weirdly, when I got to thinking about it, I noticed the following correspondences:

3+4=7
RED+YELLOW=ORANGE

2+4=6
BLUE+YELLOW=GREY-GREEN

2+3=5
BLUE+RED=VERY DARK BLUE/BLACK/PURPLE

Oh, and arguably, 3+3+3=9 (RED+RED+RED=DARK RED), if you think of three as a translucent liquid like wine getting darker as more of it is poured into a glass. Which is nice... but in general, the sum of my colours is not the colour of my sums!

When it comes to whole words, with me too, as with Waht, the colour of the initial letter usually predominates. My first, quickest, strongest, readiest association for colour words such as RED, GREEN, BLUE depends on the meaning. That’s the association I have when I just glance at the word or think of it as a whole without paying much attention. But as I look now at the letters I’ve just typed, paying more attention to them, I can’t help but “see” the colours of individual letters emerging.

R, yellow
E, reddish orange
D, black

G, dark, greyish brown
R, yellow
E, reddish orange
E, reddish orange
N, dark red

B, dark maroon
L, white
U, dark grey
E, reddish orange

I suppose it’s a bit like looking at a wire-frame drawing of a cube and seeing one corner as alternately concave or convex, I can switch perspectives by either focusing on the word as a whole, or considering its letters. That said, writing them all out vertically like this does bring out the colours of the individual letters more and make it harder to see picture the colour of the word as a whole without the colours of the letters intruding.

*

Sometimes when I’m on the verge of falling asleep, I’ll either experience a small muscle twitch or hear some small real noise, such as a creak or a click, which triggers a very short flash of visual experience, most often like a burst of TV snow.

I often have coloured reveries while listening to music, but in a freeform and voluntary way. I don’t know anything technical about music, and I don’t have colour associations with particular notes, apart from their letter names, but I do have a looser tendency to think of high notes as light, bright, small, sharp and cold/hot, while low notes are dark and big and warm. (But I don’t think that’s uncommon.) Some music gives me tingles [ http://www.cogsci.msu.edu/DSS/2008-2009/Huron/HuronFrisson.pdf ].

I like to speculate: if this smell, sound etc. was a colour or texture... But again, that's a voluntary and playful thing for fun and curiosity, and not like the automatic associations I have between colours and things like letters. Not that they aren’t fun and curious too!

 

[ViewsofMars]

"

VOM,

Sound, smell convergence, I understand what you are saying 65% of cells respond to one of 5 odors, and about 1/3rd of those same cells respond to audio, and that 29% had enhanced/suppressed to a mix of smell and sound, which explains the "crossover effect". I fully get that. I have a few questions, first the short finding in the link provided was done by: National Institute on Deafness and Other Communication Disorders (NIDCD), and I believe on a population of test subjects which which may include non-synesthetes and synesthetes alike. How do we know if they were synesthetes or not unless they were tested independently for smell/sound synesthesia before taking the test with results presented here ?

"

Rhody, you can call me Mars. It's a nickname given to me by a very famous scientist. The handle I use "ViewsofMars" means Observations (Views=Observations so I used it since it was a shorter word) of Mars. And, I don't think you do understand. I NEVER said, "65%..."


"

I will answer your question by asking another, you said, " I would like to mention if someone is experiencing symptoms of synesthesia then he/she should consult a doctor." to which I respond, why don't you ask waht or chi meson who are following this thread if they feel they need to see a doctor about their form of synesthesia, and if it in any way inhibits their normal daily lives ?

"

I don't need to ask waht or chi meson. I'm following house rules here on Physics Forums - Forum: Medical Sciences due to the fact that synesthesia is considered to be a medical - communication disorder. You can review all that scientific research I have presented. If anyone has symptoms and are wondering what is happening then obviously they should consult his/her doctor for evaluation.

"

Lastly, you said, "It also brings to light a relatively unexplored area of the brain that could play a key role in conditions which are accompanied by disorders of sensory processing, such as schizophrenia and Alzheimer’s disease." I don't know how having sound/smell synesthesia correlates to having schizophrenia or alzheimer's disease. I would like to see hard evidence, in the absence of which I would tend to doubt it.

"

Again I must repeat to you, Rhody, I did not say, "It also brings..."

"

I am not a research scientist but do not believe that the most common forms of synesthesia are "disorders". See quote from zooby in https://www.physicsforums.com/showpost.php?p=2723961&postcount=153" above: [review post #244]


Rhody...

"

Yes, I realize you aren't a research scientist. Member zooby talks a lot. I support the The National Institute on Deafness and Other Communication Disorders -"The National Institutes of Health—The Nation's Medical Research Agency—includes 27 institutes and centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases."

I'll move onto another topic. I've provided enough information between this page and the previous one.

P.S. Welcome Rasalhague. Thanks for sharing.

 

[fuzzyfelt]

Fuzzy,

and

This is very cool stuff, a further parsing, identification, localization, association and labeling of the synesthesia experience. So far, we recognize, upper, lower, projector, associator, implicit (not experienced but showing activation on scans), explicit (experienced and reported), bi-directional, bottom up (perceptual), involvement of early pre-attentive processes, involvement in later attentive processes, possible cross-activation, possible simultaneous activation, possible cross tuning model.

Crap, I gave myself a headache trying to condense it. I am sure I missed some descriptions ! lol. It must be the computer science nerd in me trying to reduce all of it into data structures. You can see what I am trying to do here, take a step back, condense, consolidate.



Rhody...

Thanks Rhody, you mentioned some things that really interest me.

There do seem many variations, and I really appreciate the condensation and will try to add to that myself, (of course, these are not necessarily all exclusive)- rare/not rare (e.g. number/spatial forms), congenital/acquired (e.g. cortical plasticity), sensory/conceptual or innate/ emotional (personification etc.), individual/universal (e.g. Dehaene’s SNARC, kiki-Bouba, Day’s take on Berlin and Kay’s colour theory- http://web.mit.edu/synesthesia/www/trends.html
http://www.informaworld.com/smpp/content~db=all?content=10.1080/02643290500200122), probably more, and also, terms- “To date, a plethora of terms have been used in the context of crossmodal research (‘heteromodal’, ‘multimodal’, ‘intersensory’, ‘polysensory’, ‘multisensory’, ‘amodal’, ‘supramodal’, ‘modality-specific’, ‘unimodal’, etc.).-2001
http://cercor.oxfordjournals.org/cgi/content/full/11/12/1110


By the way, I didn’t manage to sign myself into the site to read your link ( Multiple dimensions in bi-directional synesthesia )
about bi-directional dimensions, and found another from 2007-
http://www.apn.psy.unibe.ch/unibe/philhuman/psy/apn/content/e5616/e5621/e6314/e6342/files6343/Meier_Rothen_2007_ger.pdf
It states that a unidirectional colour experience occurred at a subjective level, but a bimodal concurrence existed at a performance level. Only associator synaesthetes were tested. Is that similar?

 

[fuzzyfelt]

I have been trying to find accurate graphics and or videos where the "normal" five senses (in a non-senesthetic individual) are thought to be processed for perspective. So far haven't come up with a good set of graphs and/or videos to address this. It would be nice to have for discussion and reference. I will keep looking.

Rhody...

I don't believe there is total agreement about these "normal" five senses, and more,
given this thread, you may need to be even more precise about what is the “ normal” senses you are looking for :).

To elaborate, my selection may be biased because this is what I’ve been looking at, but this more typical mingling of senses has been called ubiquitous, with an explosion of research away from the traditional view of isolated modes, or-

“Indeed, the multisensory nature of most, possibly all, of the neocortex forces us to abandon the notion that the senses ever operate independently during real-world
cognition.”

( http://webscript.princeton.edu/~asifg/publications/pdfs/Ghazanfar & Schroeder 2006.pdf
http://cercor.oxfordjournals.org/cgi/content/full/11/12/1110
http://ukpmc.ac.uk/classic/articlerender.cgi?accid=PMC2427054 )

 

[fuzzyfelt]

I'll make it fast since I have a project to finish up. I think my last two postings from the previous page provided valuable information, especially "A Whole-Genome Scan and Fine-Mapping Linkage Study of Auditory-Visual Synesthesia Reveals Evidence of Linkage to Chromosomes 2q24, 5q33, 6p12, and 12p12."

This has been linked to before in this thread, in post #169, and discussed a bit, for example, in post #173, if interested.

 

[fuzzyfelt]

Hey, cool, a synaesthesia thread!...

Thanks for the fantastic post!



And thanks for the fantastic links!

 

[waht]

Rasalhague, welcome to the elite club

Your post is a fascinating insight into a synesthesia perspective.

I have fixed colour associations for letters, numbers, days, months, compass directions and the concepts of left and right. I associate triangles, squares etc. with the colour corresponding to the number of their sides. Like Waht, my A is yellow. My B is a very dark maroon. But we differ on C. Mine is light green.

Nice. I counted the occurrence of most common colors of letters that I perceive in the alphabet. And the distribution is: there is seven shades of yellow, five shades of white, and four shades of red, and three of brown all spread throughout the alphabet. The remaining few letters take on more cooler colors: green, blue, purple, and black.

If I think of a letter without looking at one, it tends to have its own synaesthetic colour by default, especially if I only think of a fairly abstract idea of the letter without imagining an example of it written down, in which case I can picture it how I choose, although I’ll probably still have a lingering impression of its synaesthetic colour.
For me, yellow is an aspect or attribute of A, part of its nature, and a blue A is an A in disguise! An A in drag?! When I think of the idea now, I have to make a conscious effort to banish the impression of yellow, otherwise saying “a blue A” creates a similar visual impression to “a blue yellow”--I see both colours.

Yes, same thing happens. I realized though that a thought of a letter triggers the color experience. If I close my eyes, and think about a letter, a color jolt occurs.

When I look a blue A, this is I think a what happens. The visual part of the brain immediately registers a blue color faster than the time it takes for another part of the brain to covert the visual symbol of the letter into an abstract thought which in turn triggers the synesthesia color experience. So in a sense a resonance effect occurs, which is flipping back and forth between the color perceptions that are separated by a small time delay.

As Zooby suggested to check out the effects of grapheme synesthesia on different colors of font, and background. I found that the time delay gets noticeably longer with more flamboyant font color, and darker background.

If I need two Greek letters to represent angles, I prefer not to use the traditional theta and phi, as these are both a smoky blue colour, albeit theta a little lighter than the pigeon-blue phi. Alpha and beta, which--like most of the Greek alphabet--have the same colours as their Roman counterparts make a much better contrast. (I should say my first language is English.)

Yup, most of the Greek alphabet is isomorphic synesthesially speaking to the Roman alphabet, with an exception of few letters. Gamma is still same as 'c' , delta is same is 'd' or phi is same as 'p' - which is why I think that the visual processing of the geometry of symbols like lines, curves gets translated into a thought first, and then a color experience occurs from the thought.

So I look at a triangle letter, and think to myself "aha, that's a delta." And immediately a 'd' follows from the first word "delta" and hence I get a color experience of 'd'.

Weird one is gamma. I should get a color experience for 'g' but instead I get a color for 'c' a third letter of the alphabet as is gamma.

3+4=7
RED+YELLOW=ORANGE

2+4=6
BLUE+YELLOW=GREY-GREEN

2+3=5
BLUE+RED=VERY DARK BLUE/BLACK/PURPLE

That's a correct addition of color. For me it's yellow + red = white.

When it comes to whole words, with me too, as with Waht, the colour of the initial letter usually predominates. My first, quickest, strongest, readiest association for colour words such as RED, GREEN, BLUE depends on the meaning. That’s the association I have when I just glance at the word or think of it as a whole without paying much attention. But as I look now at the letters I’ve just typed, paying more attention to them, I can’t help but “see” the colours of individual letters emerging.

Yes indeed. The first letter sets the color of the rest of a word. But there are few exceptions in days, months, shapes, or directions that don't follow this pattern. There is a unique color for most of those.

Monday is same color as 'm' but Wednesday is different color than a 'w'.

 

[zoobyshoe]

I don't need to ask waht or chi meson. I'm following house rules here on Physics Forums - Forum: Medical Sciences due to the fact that synesthesia is considered to be a medical - communication disorder. You can review all that scientific research I have presented. If anyone has symptoms and are wondering what is happening then obviously they should consult his/her doctor for evaluation.

Quote for us exactly where it's defined as a "medical-communication disorder".

 

[rhody]

Fuzzy thanks for the link, in response to your question, see below:
You really should try to sign up and download the other paper, PM me if you like and I will walk you through the process.

By the way, I didn’t manage to sign myself into the site to read your link ( Multiple dimensions in bi-directional synesthesia )
about bi-directional dimensions, and found another from 2007-
http://www.apn.psy.unibe.ch/unibe/ph...n_2007_ger.pdf
It states that a unidirectional colour experience occurred at a subjective level, but a bimodal concurrence existed at a performance level. Only associator synaesthetes were tested. Is that similar?

The paper you provided is concerned with conditioned responses that "fire back" in bi-directional cross activation. This is for people who experience synesthesia in "the minds eye" referred to as associators. In a nutshell, what was found was a new way to test whether disasociations between conscious experience of synesthesia, and unconscious co-activation of synesthesia (by the unexpected "startle response" in synesthetes versus control individuals (who did not exhibit the startle response).

The method used to condition the "startle response" was as follows. They used skin conductive response to measure the startle reaction response. Blue was selected for synesthete's who would normally see blue when presented with a white box with the letter "A" in it. (see attached thumbnail). Test subjects were shown three colors at timed intervals (2 second exposure, then a rest period, 10 to 20 seconds to allow the skin conductive response to return to normal), when blue was shown, a boat horn with 100 db serving as the unconditioned stimulus. Red, blue and green squares were used to condition the startle response. The results implicate when the startle response was associated with the "real color", an association between the shock and grapheme (in the synesthetes's minds eye) was established. Results showed that during the conditioning phases the synesthetes would respond to the white box with the A in it as if they had been startled by the boat horn, whereas the controls did not respond. This processing is thought to occur in higher parietal cortex, particularly the http://en.wikipedia.org/wiki/Angular_gyrus" .

Compared to the other paper: "Multiple dimensions in bi-directional synesthesia", which used EEG measured event-related potentials, they were comparing associators (in the mind's eye) versus projectors (visualized in space), and synesthetes with a larger priming effect observed in the frontal and parietal electrode areas and another group in the frontal areas only. The results indicate that bi-directional activity for associator synesthetes, and that a disassociation between associator's and projectors was present. These results also show that for the first time, similar neural mechanism's underlie bi-directional synesthesia in synesthete's that do not report a synesthetic experience of a grapheme when a color is presented.

Note: Mingling terms: associator/projector in the first paper and explicit/implicit and higher/lower as one in the same thing (current thinking as of 2005) suggested by Dixon & Smilek in the second paper drove me a little nuts (no, try a lot nuts ! lol) trying to compare the two. To me, apples are apples and oranges are oranges and never the two shall meet, as a result I may have made interpretation errors in translation.

Rhody...

P.S.

I want to reread the dialog between Rasalhague and waht comparing their experiences. However, I am too tired at this point, at quick glance there may be some of their experience that is in agreement with the experiments discussed above, especially the associator parts. I will give that a harder look tomorrow, I want to do it with a fresh mind. I am toast right now. :zzz:

 

[rhody]

Fuzzy,

You asked:

I don't believe there is total agreement about these "normal" five senses, and more,
given this thread, you may need to be even more precise about what is the “ normal” senses you are looking for :).

By senses, I meant, sight, sound, smell, taste, touch and balance (edit: added 6/24, 12:34pm). What I was trying to convey, unsuccessfully was that it would be nice to have a mapping of the brain areas and descriptions of stimulus where each sense is perceived non-synesthetically under baseline test conditions.

Second, a collection of brain activation areas and descriptions where forms of synesthesia have been tested and reported. Sort of a living library if you like. Some of the paper's I have read provide a graph or two to indicate activation areas. Obviously, test conditions and technologies used to measure the synesthetic responses vary for each individual. A collection of links would suffice due to copyright issues to protect the researcher and his work.

Rhody...

 

[Rasalhague]

Rasalhague, welcome to the elite club

Heh, heh, thanks. Don't look now though, I think there's people studying us!

And thanks to everyone else for your kind comments on my ramblings...

I counted the occurrence of most common colors of letters that I perceive in the alphabet. And the distribution is: there is seven shades of yellow, five shades of white, and four shades of red, and three of brown all spread throughout the alphabet. The remaining few letters take on more cooler colors: green, blue, purple, and black.

Interesting... I have 5 shades of red (three dark, one medium and rosy/reddish-orange/vermillion sort of a colour), 4 shades each of yellow and green, and 4 identical whites (in contrast to my numbers where the two white digits are different shades). Less common colours include some light-coloured ones: the translucent quartzlike pink i, amber/peach q, orange f, besides a brown, a middle-of-the-road blue (dark blue rather than light, but not murkily so), two shades of very dark grey, a black and one metallic.

Yup, most of the Greek alphabet is isomorphic synesthesially speaking to the Roman alphabet, with an exception of few letters. Gamma is still same as 'c' , delta is same is 'd' or phi is same as 'p' - which is why I think that the visual processing of the geometry of symbols like lines, curves gets translated into a thought first, and then a color experience occurs from the thought.

So I look at a triangle letter, and think to myself "aha, that's a delta." And immediately a 'd' follows from the first word "delta" and hence I get a color experience of 'd'.

Weird one is gamma. I should get a color experience for 'g' but instead I get a color for 'c' a third letter of the alphabet as is gamma.

My gamma is dark brown like g, but a bit darker and greyer. Phi is more like p than f. For me, the exception is theta, which has this pale smoky grey-blue colour, unlike my dark green t. The Old English / Icelandic / runic letter "thorn" has the same colour as theta [ http://en.wikipedia.org/wiki/Thorn_(letter) ], as does Tuesday. But, just to be awkward, Thursday is a different kind of pale grey.

That's a correct addition of color. For me it's yellow + red = white.

I wasn't expecting to find any, so I was quite excited to find those three. But I can't see how it could work in general.

Yes indeed. The first letter sets the color of the rest of a word. But there are few exceptions in days, months, shapes, or directions that don't follow this pattern. There is a unique color for most of those.

Same here. East and south match their initial letters, but north and west do their own thing, espcially west which is nothing like any of its individual letters. The months are a similar mixture of ones with colours that match the initial letter, such as January and December, and others like June, September and November that diverge.

Monday is same color as 'm' but Wednesday is different color than a 'w'.

My Wednesday is orange, more like its second letter than it's first, although more f-coloured really. Monday is black, possibly due to the /u/ sound.

Incidentally, when I started school, for the first year, we were taught an experimental phonetic spelling system called ITA, Initial Teaching Alphabet [ http://www.itafoundation.org/alphabet.htm ], [ http://news.bbc.co.uk/1/hi/uk/1523708.stm ]. But I can't remember whether I had any colour associations at that time. When I look at the ITA alphabet now, I have all the associations I would have for the corresponding normal letters.

*

The abstract I mentioned was a bit ambiguous (and I don't have access to the full article), but I think they meant they found a correspondence between the frequency with which a colour occurs in a synaesthete's alphabet and the frequency of the corresponding colour term (the word)--rather than the frequency of the colour, since these colours aren't all pure colours and have other distinguishing features besides frequency.

Synaesthetes tend to associate higher frequency graphemes with higher frequency colour terms. For control participants, choices are influenced by order of elicitation, and by exemplar typicality from the semantic class of colours.

Anyway, here are some charts I made, inspired by that idea. In the one on the right, letters of the alphabet arranged by frequency, compared to the frequency of occurrence of the English colour terms from the set { orange, pink, yellow, silver, silver, grey, brown, green, red, white, black } which I judged the best match for the synaesthetic colours I associate with them. Letter frequencies from Wikipedia [ http://en.wikipedia.org/wiki/Letter_frequency ]. Frequency of colour terms from BNC [ http://corpus.byu.edu/bnc/ ].

In the bar chart, colour words from left to right in order of increasing frequency versus how often a colour in that range occurs in my alphabet. As mentioned, except for white, multiple occurrences include several different shades. In some cases, the choice of which colour to include where is a bit arbitrary. Also what to call them (silver?, metallic?). To simplify that, I chose colour terms that I'd have known at the age I was first aware of these associations. More obscure and precise terms would make some of them arbitrarily very infrequent. Another problem is that some of these terms denote other things besides a colour. Not all that revealing, perhaps, but at least it gave me some practice learning how to do graphs in Mathematica.

 

[rhody]

Rasalhague, waht,

First, thanks to you and waht for contributing and comparing your perceptions and the frequency analysis you did, very cool.

From you last post:

Synaesthetes tend to associate higher frequency graphemes with higher frequency colour terms. For control participants, choices are influenced by order of elicitation, and by exemplar typicality from the semantic class of colours.

See Wapedia http://wapedia.mobi/en/Synesthesia"

For example, sound-color synesthetes, as a group, tend to see lighter colors for higher sounds [20] and grapheme-color synesthetes, as a group, share significant preferences for the color of each letter (e.g., A tends to be red; O tends to be white or black; S tends to be yellow

Funny how your word frequency has the highest concentration in red, followed by yellow and green tied for second place. I never realized from what you experience that the first letter of the word predominates at a glance, but if you pay attention to it you said:

paying more attention to them, I can’t help but “see” the colours of individual letters emerging.

That makes me wonder if given more brain decoding and processing time your synesthetic brain completes the sequence. Would you mind trying a little experiment ? Using your your "blue" because of the high contrast between letters:

B, dark maroon
L, white
U, dark grey
E, reddish orange

Type these letters one space apart and glance, record what you see, look away, then look with full attention, record what you see, repeat this exercise increasing the space between each letter by one, note the results, until all letters take on their full color, trying to note the time interval (blending effects left to right), I know this is not easy. Repeat this exercise in the vertical like you see above, same deal, finally in diagonal left to right (top bottom) and again diagonal with the order of the diagonal reversed.

Where I am going with this is the visual and spatial reasoning processing areas in the brain, from: "The Brain that changes Itself", by Norman Doidge, page 34. maybe there is a "spatial component" to the sensation as well.

"in the left hemisphere, at the junction of three major perceptual areas where the temporal lobe (which normally processes sound and language), the occipital lobe (which normally processes visual images), and the parietal lobe (which normally processes spatial relationships and integrates information from different senses) meet"

If your test results indicate slight color and time to full color differences in how they are perceived even for the briefest of moments that you recognize them, it may indicate activity in the occipital and parietal lobes that differs in how non-synesthetes perceive and process letters (without color). Since you are good with numbers, you said you use mathematica to create your graphs, I know you will do well with this impromptu little test. Try as best you can to see if you can detect any timing of color change between letters spaced at increasing distance in all three axis, horizontal, vertical, and diagonal (both ways).

Some grapheme → color synesthetes report that the colors seem to be "projected" out into the world (called "projectors"), while most report that the colors are experienced in their "mind's eye" (called "associators"). [24] It is estimated that approximately one or two per hundred grapheme-color synesthetes are projectors; the rest are associators.

Finally, do you or waht or anyone else have the projector experience ?

You also said,

Sometimes when I’m on the verge of falling asleep, I’ll either experience a small muscle twitch or hear some small real noise, such as a creak or a click, which triggers a very short flash of visual experience, most often like a burst of TV snow.

I am not synesthetic in any way but did relate an incident when falling asleep reading a computer monitor with black and white text, that in the moment when the head bobs and you regain focus on the black words on a white background are suddenly neatly surrounded by dark red semi-circles in front of and behind each word. I dozed off a second time, my head dropped even lower, this time when I opened my eyes at a lower orientation the line of words had two of them outlined in brown and one in green. I was surprised but not shocked, having been reading about synesthesia for months. That was the first incident.

The next incident similar to yours was being awaken suddenly a few weeks ago by strong thunder and lightening. Maybe you are too young to remember but the old style analog TV sets when you turned them off the picture used to reduce to almost a tiny glowing ball for a few seconds before flickering out. As I dozed off after a thunder clap, a small wispy ball (similar to the TV ball)appeared in the center of my minds eye, it started off as deep blue grew in a swirling mist, taking on a greenish tinge as it grew, to about 1/10 of my minds eye's viewing area before evaporating. It lasted five to ten seconds. I woke up with the properties of it in clear detail. A few weeks later another thunderstorm that woke me did not produce the same effect however.

Rhody...

P.S. waht or anyone else with color-grapheme synesthesia you are more than welcome to try this little test, just use a word which has high contrast colors between the letters, they are different for most everyone.

I attached a graphic thumbnail for Regions thought to be cross-activated in grapheme-color synesthesia (green=grapheme recognition area, red=V4 color area).

 

[fuzzyfelt]

Thanks Rhody, especially for your offer and detailed answer. I think you’ve answered it well for me. My wonder was how “projectors” fared, and as well I'm interested in "performance", but not "subjective experience", levels. To your note, I wonder whether the higher/lower terms may be being abandoned as of that latest paper ( http://psy2.ucsd.edu/~dbrang/images/brang_neuroimage_2010.pdf ).

Sorry I hadn’t been more helpful before regarding your query. These probably aren't too helpful by way of functional images of sensory systems. The first explains a bit about mapping, but is mainly limited to the primary visual cortex (V1)- and concerns about plasticity.


http://www.med.harvard.edu/AANLIB/home.html
http://www.med.harvard.edu/AANLIB/cases/caseNA/pb9.htm

 

[Rasalhague]

Type these letters one space apart and glance, record what you see, look away, then look with full attention, record what you see, repeat this exercise increasing the space between each letter by one, note the results, until all letters take on their full color, trying to note the time interval (blending effects left to right), I know this is not easy. Repeat this exercise in the vertical like you see above, same deal, finally in diagonal left to right (top bottom) and again diagonal with the order of the diagonal reversed. [...] Try as best you can to see if you can detect any timing of color change between letters spaced at increasing distance in all three axis, horizontal, vertical, and diagonal (both ways).

This is tricky. I began by looking at a sequence of horizontal BLUEs with increasingly many spaces, but--perhaps having synaesthesia on my mind--I saw the individual letter colours from the beginning, even on the one where they weren’t separated by any spaces. (I’d arranged them in a word file spaced one to a page so that I could scroll from one to the next with a mouse click.) I did some typing on an unretated subject, then tried again. This time it began with a fairly prevailing sense of blue, although I was aware of the individual colours too to some extent. The initial B actually started off with the blue colour I associate with P. But I was also to some extent aware of the white of the L and the grey of the U which gave it the ambience of a blue sky dotted with white and grey clouds, or of white and grey stone buildings under a blue sky. I didn’t have any clear picture of a fully realized scene of that sort; it was just a vague impression of the atmosphere evoked by the colours. The one thing that changed with the spacing happened quite suddenly. When I got to either 7 or 8 spaces (at that speed, about 3 clicks a second, and trying to concentrate on the colours, I lost count a bit), the B switched from blue to black, closer to it’s own very dark russet brown colour. Calling it maroon or brown might give the wrong impression: its own colour is very dark, with purplish qualities even. Imagine an old crayon in a school crayon pot that's got caked in the colour of so many crayons it's almost black! Subsequent tries: nothing so sudden. Sometimes the B takes on the blue colour from the word's meaning, sometimes it's darker, more like its own colour, or somewhere in between: a very dark blue contrasting with the white of the L.

The variations are so subtle, complicated and mostly so continuous that it's hard to know what to time. When I look at the words YELLOW, GREEN, ORANGE, PURPLE, BLUE, WHITE, BLACK here in text next to each other, the word colours prevail at a glance, but the emergence of the letter colours can happen too fast to time with a simple slight shift of focus in my attention, intended or otherwise. Calls to mind William James's "turning up the gas to see how the darkness looks". And it's not strictly one or the other: I can be more aware of the word colour or more aware of the letter colours but without excluding awareness of the other. And, as with the B of BLUE, the word colour can sometimes have a bigger effect on one letter than on others.

I'll play with this some more and with more arrangements as you suggested. I've tried it with a short sequence of random colour words, each a different random spacing, most horizontal but a few vertical, and running through them quickly to see what the experience is like and what it might be possible to quantify. First impressions: at the moment the colours of the letters are mostly trumping the semantic colours of the words, even without much spacing. As with BLUE, it's the initial letter, the dark grey-brown G of GREEN that's most inclined to take on a hint of green, although it keeps a lot of its own quality. As I click through them, it's like a greeny brown, olive, woodland hue on the left, next to the yellow R, then there's the bright orange-red EE and the dark red N. It makes a nice combination. As BLACK flashes past, its most salient features are the initial B which again accommodates itself to the word colour and becomes completely black, contrasting strongly with the yellow A in the middle. Seen quickly, the other letter colours in this one don't get much of a look in. A waspish combination. The letters of RED stay quite distinct in the various arrangements I've set up, with just a little bit of bleed through of the red E to the R. I only included one ORANGE, without spaces, and it flashed by an orange colour, so that should make a good one to study as it's initial letter is white, and so makes a bigger contrast with the word colour than some of the others. Looking at it now, and shifting focus back and forth, I could even express it the other way around: the orange "emerging" through the white and suffusing the yellow of the A in the middle and the slightly darker yellow R, leaking out from under the very dark red N, but leaving it and the dark grey-brown G least affected. (The E, already reddish orange, of its own accord.)

Just tried the BLUEs again, after a break, and again the B started out more blue and switched to black, this time on 6 spaces. (Times New Roman 12 point, zoom 200%, screen a handlength out of reach).

Well, I'll have a go at setting up some more orderly tests with other words too.

Finally, do you or waht or anyone else have the projector experience ?

I think I'm probably just common-or-garden "associator", if I understand the distinction right. I'll have to read up more on the definitions, but when I’m prompted to think of a single letter, the colour is in my mind’s eye, not projected onto whatever I happen to be looking at in the outside world, and it’s not particularly localised in my mind’s eye unless I start imagining the letter in relation to other letters or objects. When I look at the letters I’m typing now, I’m not in any doubt that they’re all black; I don’t see their associated colours blotting out their real colours. That said, when I become aware of them, the associated colours are localised by the positions of the letters on the screen. I can cast my eye over a bunch of paragraphs, without paying attention to the meaning of the words, and take in lots of colours without a noticeable delay, at the same time as each other, each localised at the corresponding letter, the colour perceived subtly somehow in parallel to the letter rather than superimposed on it. The real colours out there dominate, but the associated colours do have a spatial connection to the locations of the letters, so I'm not sure whether that would be called projection. It's not intrusive though, if that makes any sense...

So the coloured letters in the Wikipedia article are not really like how I perceive a bunch of monochrome letters and numbers in the outside world. They’re perhaps closer to how I think of letters most naturally if I have to imagine them without a real-world visual prompt, although in that case, the colour can be the predominant visual part of the experience and manifest even if I don’t go as far as picturing a particular way of writing the grapheme, or only vaguely visualise the shape. As for their choice of colours, the ones that clash with mine stand owt liKe an obViouslly missPelt wword. I can well imagine it distracting me and tripping me up if I had to remember a bunch of arbitrarily coloured letters and numbers like this or answer questions on them in a hurry.

Regarding the comment in the aricle about vowels and consonants, they’re equally vivid for me.

 

[rhody]

Rasalhague,

Thanks for your attempt at this. I know it is not easy. In the meantime I am looking into the nuts and bolts of: http://en.wikipedia.org/wiki/Eye_tracking" , what the current technology is like and what background information there is that may help refine this little test (without technology, hehe), I always try to improvise and adapt to whatever situation I find myself in anyway, so it is a natural thing for me to do.

I will give your first results a harder look later and get back to you, thanks for your participation in this little exercise, you are a good sport.

Rhody...

 

[Rasalhague]

In the meantime I am looking into the nuts and bolts of: http://en.wikipedia.org/wiki/Eye_tracking" , what the current technology is like and what background information there is that may help refine this little test (without technology, hehe), I always try to improvise and adapt to whatever situation I find myself in anyway, so it is a natural thing for me to do.

It crossed my mind too, for example whether someone could identify the "wrongly coloured" letters from a set that included some right and some wrong, for a given grapheme synaesthete, judging by how long they spent looking at them--thinking of how the wrongly coloured letters in that image near the top of the Wikipedia article attracted my attention like spelling mistakes while I tended to skim over the correctly coloured ones, taking them more for granted.

 

[rhody]

RasalHague,

Nice post and interesting results, you said,

The variations are so subtle, complicated and mostly so continuous that it's hard to know what to time.

I agree, as an adaptation we could try using powerpoint, create slides with words, with timed unmasking of words and sequences of letters using different widths and time between letters, (this would ensure consistency and repeatability to the test). This is the long hard way to do things but is the most flexible.

Or use an online color-grapheme test if one is available (which may not be as flexible as we would like, a tradeoff). There are (at least) two more variables to consider, one, eye tracking, after reading the article in full I realize that there are many things to consider, the most important was the way the eyes process move to distinguish and then process data, through fixation and http://en.wikipedia.org/wiki/Saccade" except below:

Function:
Humans and other animals do not look at a scene in fixed steadiness; instead, the eyes move around, locating interesting parts of the scene and building up a mental 'map' corresponding to the scene. One reason for the saccadic movement of the human eye is that the central part of the retina—known as the fovea—plays a critical role in resolving objects. By moving the eye so that small parts of a scene can be sensed with greater resolution, body resources can be used more efficiently.

In addition, the human eye is in a constant state of vibration, oscillating back and forth at a rate of about 30–70 Hz. These microsaccades are tiny movements, roughly 20 arcseconds (one five thousandth of a degree) in excursion and are completely imperceptible under normal circumstances. They serve to refresh the image being cast onto the rod cells and cone cells at the back of the eye. Without microsaccades, staring fixedly at something would cause the vision to cease after a few seconds, since rods and cones respond only to changes in luminance.

Timing and kinematics:
Saccades are the fastest movements produced by the human body. The peak angular speed of the eye during a saccade reaches up to 1000°/sec in monkeys (somewhat less in humans). Saccades to an unexpected stimulus normally take about 200 milliseconds (ms) to initiate, and then last from about 20–200 ms, depending on their amplitude (20–30 ms is typical in language reading). Under certain laboratory circumstances, the latency of, or reaction time to, saccade production can be cut nearly in half (express saccades). These saccades are generated by a neuronal mechanism that bypasses time-consuming circuits and activate the eye muscles more directly.[3][4]

The amplitude of a saccade is the angular distance the eye travels during the movement. For amplitudes up to about 60°, the velocity of a saccade linearly depends on the amplitude (the so called "saccadic main sequence"). For instance, a 10° amplitude is associated with a velocity of 300°/sec, and 30° is associated with 500°/sec. In saccades larger than 60°, the peak velocity starts to plateau (nonlinearly) toward the maximum velocity attainable by the eye.

Saccades may rotate the eyes in any direction to relocate gaze direction (the direction of sight that corresponds to the fovea), but normally saccades do not rotate the eyes torsionally. (Torsion is clockwise or counterclockwise rotation around the line of sight when the eye is at its central primary position; defined this way, Listing's law says that when the head is motionless, torsion is kept at zero.)

Head-fixed saccades can have amplitudes of up to 90° (from one edge of the oculomotor range to the other), but in normal conditions saccades are far smaller, and any shift of gaze larger than about 20° is accompanied by a head movement. During such gaze saccades, first the eye produces a saccade to get gaze on target, whereas the head follows more slowly and the vestibulo-ocular reflex causes the eyes to roll back in the head to keep gaze on the target. During these head movements Listing's law is no longer obeyed.

Saccades, as well as microsaccades, can be distinguished from other eye movements (ocular tremor, ocular drift, smooth pursuit) using their ballistic nature: their top velocity is proportional to their length. This property can be used in algorithms for saccade detection in eye tracking data.

In addition if you look at this figure: see attached thumbnail: you will see the fixation times vary, for instance in the fourth line down, after "syd-" the eye slowed to analyze the hypen and space after it. Interesting...

The second issue is environment you test in, preferably a comfortable place with few distractions.

You also said,

The letters of RED stay quite distinct in the various arrangements I've set up, with just a little bit of bleed through of the red E to the R

that is interesting because for you red is your most predominant color, maybe it is "most quickly primed in your visual cortex", you said it was "quite distinct".

A lot to consider and I think you will agree not an easy thing to do after taking a peek a "bit deeper under the covers", I for one appreciate a more detailed understanding of how we visually acquire and process information, which can't be a bad thing, right ? hehe.

--------------------------------------------------------------------------------

All of what follows is my on-line search for a test close to the one we have in mind. A scary thought just came over me, what if no one has ever done this test before, hmmm.

I found this http://www.synesthete.org/files/EaglemanetalSynesthesiaBattery2006.pdf" by Dr Cytowic including results from: "A new measure: the speeded congruency test" but this was only for recognizing individual letters. You may find this interesting because it shows with 1 to 2 ms accuracy how synesthetes differentiate individual letters on various levels of shaded backgrounds.

You may find this interesting as well: http://steverudolfi.com/synesthesia/viewAll.php" where all people reading this thread can take the test and then record for posterity their personal maps !
There are about two dozen or so there right now. I found it interesting, (assuming of course that most of the testers did not lie cheat) that there were some "fragmentary associations". This is consistent with waht experience for sound -> color, only certain frequency ranges played a specific way for a specific duration cause the sensation.

I also found this: http://synesthete.org/" From a quick scan of it, it doesn't seem to have the test we are trying to accomplish.

I can't say for certain, but after a substantial time of not finding a similar test, then it's back to doing it the hard way. What do you think, RasalHague, should I play with Powerpoint to see if I can come up with automated timed slides ? Do you have any creative ideas ? I am open to them, or from anyone else following this thread ?

Rhody...

P.S. I will be away for the next two days without computer access so, please don't get the wrong impression, I will check back in on Sunday evening. Thanks...

 

[rhody]

No one may have noticed but back in https://www.physicsforums.com/showpost.php?p=2773738&postcount=254" I edited in the following possible type of synesthesia: balance

By senses, I meant, sight, sound, smell, taste, touch and balance (edit: added 6/24, 12:34pm)

I have put the PowerPoint slide test on hold for a bit, once again my curiosity got the best of me, so its off to search for examples of where balance (also known as kinetics) and one or more additional senses may be linked. The reason I added it was of a heart wrenching story about a young women who http://www.medmovie.com/1190/1190_031_Vestibulocerebellum.swf" was 98% destroyed because of a rare side effect from taking, gentamicin. The balance system in the body is closely linked as one would imagine with visual processing. That story is fascinating in and of itself, and I will tell the complete story of this young woman in another thread. I have to finish the book first. Back to the subject at hand, then.

As usual after a moderate search I found this http://www.wrongdiagnosis.com/n/nervous_system_conditions/subtypes.htm" as United States Flag 1,056 Traffic Rank in US, so it is very very good. I found it a bit difficult to navigate, but on the flip side I did find new types of synesthesia previously uncatagorized, including my sought after prize, balance (referred to as kinetics) see attached thumbnail for the types.

I only provided a link to nervous system conditions section. There is a vast, huge amount of categorized information here, From what I have seen so far it is free and appears fairly current and reliable, and accurate as well. The only downside is that the details of lots of conditions point you to books for bucks. That is a bummer, the upside is that there is hundreds of nervous system conditions displayed which is very very good. A quick medical reference definitely comes to mind if you need one.

Let's see, opening the thumbnail. almost at the bottom of the list, "orgasm to color" synesthesia, lets... not touch that one, I don't want this thread locked after all this work, lol. Now, moving on at the bottom, there is time to space synesthesia. Hmmm that looks worth looking into. I will leave it to the readers of this thread to contribute to as yet discussed types. Please do so if you find one that matches your experience. We would really like to hear what you have to say.

Note, By now, some of you are probably starting to think, "is Rhody obsessed with this ?", for the record, the official answer is: No. Having said that, there is so much to left to explore here that I find myself probing wider, deeper than I normally would, without the wonders of google, this would not be possible, taking my time as I do so. I still find the time to enjoy family, sports, hobbies (other than PF), work, well let's forget that part, heh, heh. Before 2000 and internet/google research went like this: hear about a subject, go to library, bookstore, find read a book, use reference to find the next, wash, repeat, now all of these activities are reduced to minutes, and in some cases seconds to build a huge tree of information to be filtered, investigated and to some degree vetted as well.

Rhody...

 

[fuzzyfelt]

I don't want the thread locked either. A little related to both sense and different types of synaesthesia are a couple of mentions on the web of "velociperception", but they aren't peer-reviewed as far as I know, and I don't know if it is acceptable to discuss things like that here. Also there was mention of musical chills here, and I think there are a few more types or sensations I've read about.

 

[rhody]

Fuzzy,

Whew, no thread lock, now I feel better.

RasalHague,

I have Powerpoint on my PC and will start investigating some templates and timer classes to see if we can't pull off this little test. I will try to make it simple, but produce some stats that you can e-mail me. I need to investigate it further, but I will probably need to e-mail you a .ppt file via e-mail to make this fly.

In the mean time in the course of reading another book, I found this: regarding savant experiences with synesthesia: from: Brain that changes itself, Norman Doidge, page 270:

Russian neuropsychologist Aleksandr Luria worked with a mnemonist, or memory artist, 'S", who could memorize long tables of random numbers, and made a living performing these skills. S had a photographic memory, going all the way back to infancy, and was also a "synesthete", so that certain senses, not normally connected, were "cross wired". High Level synesthetes can experience concepts, such as days of the week, as having colors, which allows them to have particularly vivid experiences and memories. S associated certain numbers and like Michele, could not often get to the main point

Ok, you are probably thinking to yourself, who is Michele. Here is the mind blowing part: Michele is a seemingly healthy middle aged woman who is very special. She was born without the left hemisphere of her brain. She doesn't see color for a day of the week, she sees whole scenes when she reads words. In the example in the book, she says:

For Monday I picture my classroom at the Child Development Center. For the word, 'hello' I picture the little room off to the side of the lobby of Belle Willard.

and

"Holy Cow!" Carol (her mother) erupted. She explained that Michele went to Belle Willard, a special education center, from the time she was fourteen months until she was two years and ten months.

The "Holy Cow" line gave me a chuckle, because I have used a similar line, "Holy Crap" more than once in this thread. I am glad to know it is not just me. hehe.

Michele's survival and development is a fascinating story which I plan to cover in full in another post in another thread on another subject in the future. Just thought you might like that little story.

Rhody...

P.S. I believe the use of High Level synesthesia is reserved for more abstract concepts for things like days of the week, and in my mind at least cannot see how they could be Projector like event, it must be in the person's minds eye, referred to as an https://www.physicsforums.com/showpost.php?p=2773373&postcount=253" event. So we still need to keep higher and lower as well when referring to the abstract such as days on the week, in addition to projector and associator. grrrr... Just when I thought things could be simplified a bit I guess they can't.

 

[rhody]

Holy ... !

I was looking at a web page in deep blue, almost purple background http://projectavalon.net/forum/showthread.php?t=1785", with white lettering:

Guess what I saw: partial grapheme -> color synesthesia for letters:

lower case: n,d,h,p,u,f,t,g,n light green
lower case: l,i,o,e,1,8 light pink

Holy crap ! If I rapidly open, close and strobe my eyes, more than 3 times a second, the effect goes away and the letters are pure white !

Woo hoo... now I know what partial grapheme -> color associative synesthesia feels and looks like.
I swear to God, I am shaking as I type this. I can't freaking believe it. By sheer chance, in a search for a missing scientist of all things, thanks, Dr Li, I hope you are alright and they find you intact somewhere.

Rhody...

P.S. RasalHague, do some 3 to 5 second stobing with your eyes, both, left only, right only, and let me know what you see, just for comparison.
Now that I know my form of synesthesia only manifests with dark/blue/purple background, try my page as well with white lettering and let me know what you see.

 

[waht]

Wow Rhody! I don't know what say. This is really exciting. Have fun exploring it.

It also further confirms a widespread occurrence of fragmentary synesthesia.

I've looked at your background, and just as I suspected it's sort of uncomfortable for me to look at. My regular synesthesia is still there, but it takes longer to get a color kick than if the background was lightly colored with dark font.

 

[rhody]

Wow Rhody! I don't know what say. This is really exciting. Have fun exploring it.

It also further confirms a widespread occurrence of fragmentary synesthesia.

I've looked at your background, and just as I suspected it's sort of uncomfortable for me to look at. My regular synesthesia is still there, but it takes longer to get a color kick than if the background was lightly colored with dark font.

waht,

Thanks, try this little exercise with what stimulates color with you. Starting at a slow pace, open and close your eyes staring at letters that normally produce color backgrounds, increase the rate of blinking until the letters appear black with no background as they should. Let me know what rates seem to work for you.

Rhody...

 

[fuzzyfelt]

Wow, Rhody!

 

[rhody]

After my discovery of partial grapheme -> color synesthesia the other day, I reconsidered the Test I was proposing in Powerpoint with RasalHague. I think using Visual Basic would be more flexible and allow for different backgrounds, font choices/sizes/colors, for comparison to see if the exact timing and bleeding into the characters can be pinned down per individual case, or make them disappear altogether with subtle changes to font choice/size/color.

I find it interesting that I can negate the effects of if entirely when I close and open my eyes rapidly, forcing my visual cortex to recreate from scatch if you will the entire viewable area minus the colors over the white letters.

I need a bit of professional advice here, from my "seat of the pants experiment", I reckon, (hey, I like that non professional word, lol) that the synesthesia effect disappears somewhere around 8 to 10 eye blinks a second, between 100 - 125 ms.

Can someone who is a professional (SW, perhaps) point me to a good time reference of how long each phase takes to process an image in the visual cortex, and what each stage is referred to and link(s) to subsequent stages ? What about the startle response ? Is it being reset somehow every time I blink quickly ? Or over some time period ? One would think that the brain would figure out after many blink cycles, hey, those fragmented selection of letters are supposed to be light green and pink, now I am going to make them that way !

Now that's interesting, the more the vision is corrected for one eye than the other results in the synesthesia happening quicker, when my left eye only (the weaker one the letters not as clearly defined is blinked at the 8 to 10 times per second, the pink/green letters don't seem to appear at all, the right eye (not astigmatic but a bit far sighted) the letters are much more pronounced (in my mind's eye at least being pure white) and the letters are sharper and crisper, in this case after a number of blink cycles (past 10 - 15 seconds) the faint pink (first seen) followed by green letters appear. To me this means that precise image of the grapheme within the brain is critical to create the colored synesthesia. Second, once the "startle response" detects no change then the grapheme -> color synesthesia appears again as if by magic.

RasalHague, tell me you have 20/20 vision, please, only kidding. I want to try to account for as many possible variables as possible. You are seeing coarse grained tests turn up more and more variables to account for when synesthesia is being turned on. In my case it is the sharpness of the white letters. That's science for you.

Rhody... Just playing with you... hehe

 

[HeLiXe]

Well...I came here because I thought I experience synesthesia sometimes...but now that I perused the wiki article...I don't know!

I normally have color experiences when I lose large amounts of sleep. What happens is I see color between the edge of objects...like if I look at popcorn ceiling there is color between the popcorn in certain places, or color between the wall and the door, or color everywhere in general lolol. What's weird is I have an understanding of the color as if it has its own story and I experience positive emotions in relation to the stories of the color. It is not like enjoying a color, but like experiencing it and understanding it. I don't know why this would happen with large amounts of sleep lost. In psych class we just learned about color perception and the thalamus, and I can understand one of the color theories as it relates to the thalamus because in regular waking state I can sometimes see alternations between violet and yellow and magenta and green...well maybe the violet is more like an indigo. AND I have never used any drugs like LSD or any illegal things...just coffee and tylenol :D