Article

[bjf]

http://www.scienceblog.com/community.../20035356.html

November 2003

From Society

for Neuroscience

Human senses not distinct, but interact in many ways, studies show
NEW ORLEANS, Nov. 10

- Until fairly recently, scientists believed that the information gathered by each of the senses -- touch, sight,

hearing, smell and taste -- was processed in separate areas of the brain. Research is now revealing, however, that

there is a complex interaction between the senses in the brain--an interaction that enables us to understand the

world in a unified way.
"Since we perceive the world as a whole and not split up into different sensory

modalities, it's important to study how signals from the senses affect each other in the brain," says Colin

Blakemore, PhD, of Oxford University.

New research on how the senses interact is revealing some fascinating

findings: What we see affects how we perceive odors. Blind people do have a superior sense of touch. And the odd

mixing-of-the-senses condition known as synesthesia, in which people claim to "see" sounds or "hear" colors, is a

very genuine phenomenon.

Blakemore's colleagues at Oxford, led by Gemma Calvert, DPhil, have recently

completed studies that help explain how the brain combines sight and smell to amplify our perception of various

odors. Although it's believed that humans can recognize up to 10,000 different odors, we still have a poor sense of

smell compared to other animals. To assist our sense of smell, we often rely on additional information from our

visual system.

Earlier experiments have shown that when people are asked to smell an odorized liquid that has

been tinted with an appropriate color (red for strawberry, for example), their perception of the intensity and

pleasantness of the smell is greater than if the liquid is inappropriately tinted (green for strawberry) or not

tinted at all. For their current study, the Oxford researchers wanted to find what happens in the brain when odors

are matched or mismatched with pictures. Does the smell of an orange elicit a stronger response in the brain if

it's co-presented with a picture of an orange rather than a picture of toothpaste, for example?

The study

used functional magnetic resonance imaging (fMRI), which measures changes in blood flow in the brain while a task,

such as smelling a scent, is carried out by a person lying in the scanner. When brain neurons become involved in a

task, they increase their firing rate, which leads to a change in blood flow to the brain area(s) where the

activated neurons are located. The fMRI scanner detects that increased blood flow, thus identifying which areas of

the brain are involved in the task.

The 12 volunteers in the Oxford study were placed in an fMRI scanner and

then shown matched and mis-matched combinations of odors and pictures (a strawberry odor with a picture of a

strawberry, for example, or a strawberry odor with a picture of an orange). "We found that areas of the brain

involved in smell perception respond differently to the picture-odor combinations," says Calvert.

"Some

regions--especially the orbitofrontal cortex and the amygdala, which are both involved in smell--responded more

strongly to congruent than to incongruent picture-odor combinations." This finding indicates, she says, that the

brain amplifies information gathered from those two senses when the information fits well together.



Calvert and her colleagues plan next to investigate if this multi-sensory effect is stronger for

food-related smells than for other smells.

Although it's a common popular belief that blind people have a

superior sense of touch, the research on this topic, which has spanned nearly 100 years, has been controversial. New

findings from Duquesne University in Pittsburgh, Pennsylvania, may, however, finally put this question to rest.

Using rigorous experimental techniques, DU researchers have found that blind people do have a superior sense of

touch.

For this study, Daniel Goldreich, PhD, and his colleagues tested 47 sighted and 37 blind volunteers,

ranging in age from about 18 to 70. The scientists constructed a special, computer-controlled device designed to tap

index fingers with different pieces of plastic. Some pieces were completely smooth. Others contained thin grooves of

various widths cut into their surfaces. In general, the narrower the grooves, the more difficult it is to feel them.

During the experiment, the volunteers were asked to determine which piece was touching their finger, but without

moving the finger. Thus, the test measured what is known as "passive tactile acuity" rather than "active tactile

acuity," for which the finger is allowed to move. Each tap lasted for one second, and the force of the tap was

light: either 10 grams or 50 grams. By tapping with pieces of different groove width, the scientists were able to

determine the minimum groove width that each volunteer could reliably distinguish from a smooth surface.

"On

average, blind people were able to distinguish thinner grooves than sighted people," says Goldreich. Although the

sense of touch declined with age at a similar rate in the blind and sighted groups, the sense of touch of the

average blind person in the study was about as good as that of an average sighted person who was 23 years

younger.

"We also found that people who were born blind didn't have a better sense of touch than those who

became blind later in life," says Goldreich. Nor did the ability to read Braille enhance a blind person's sense of

touch. Goldreich and his colleagues found that blind Braille readers had no better sense of touch than blind

nonreaders.

The sighted people in the study were tested with their eyes uncovered and in a lit environment.

Goldreich is now investigating whether the tactile acuity of sighted people improves if they are temporarily

deprived of vision.

One of the more fascinating mixing of the senses is a condition known as synesthesia,

which affects about one in every 2,000 people. People with synesthesia claim that real sensory experiences trigger

other entirely inappropriate perceptions. For instance, they might "see" sounds, "hear" colors, or "feel" tastes.

The condition is not a new one; it has been known to the scientific community for at least 300 years, although it

hasn't been much investigated until relatively recently, and some still doubt whether it is a genuine neurological

condition.

A common type of synesthesia is "colored-hearing." People with this condition see specific colors

in their "mind's eye" when they hear words, letters or numbers spoken out loud. The term "mind's eye" is used

because although these people see the colors in front of them, the colors don't interfere with their normal vision.

Another common type of synesthesia is "colored-touch." People with this condition see colors when they feel certain

objects.

To learn more about synesthesia, Colin Blakemore's team at Oxford University recently studied an

interesting subgroup of people with the condition--people who say that they have been colored-hearing synesthetes

all their life, even after becoming blinded by injury or disease to the retina. "We wondered whether they might be

just imagining remembered colors rather than having genuine visual sensations, so long after losing their real

sight," says Megan Steven, a graduate student at Oxford and the lead author of the study.

Six volunteers with

colored-hearing synesthesia who had been blind at least 10 years participated in the study. They were asked to

describe the colors they saw when hearing the names of each day of the week, month of the year, letter of the

alphabet and/or number from 1-100 (counting by tens after the first 10 digits). Their responses were recorded. Two

months after this initial screening, the volunteers were surprised with a second, identical test.

"What we

found was an amazing correlation between the two testing days," says Steven. "If a subject said that A was pale

green on the first testing day, they would say that the letter was a light or pale green on the surprise testing day

two months later. This is strong evidence that they were experiencing a genuine phenomenon--they actually appeared

to be seeing colors in their mind's eye, even though they had been blind for at least 10 years." These findings

suggest, she adds, that the visual areas of the brain can still remain active after blindness.

Two of the six

volunteers also had a special form of colored-touch that Steven coined "colored-Braille," which caused them to see

colors when they read Braille letters. The repeat test showed that their responses to the colors they "touched" as

they read were also genuine. Since they learned Braille after they started to become blind, this implies that the

connections in their brains leading to the color sensations were established through some kind of learning.

Synesthesia runs in families and almost certainly depends on a genetic factor. However the particular form that it

takes might depend on individual experience.

In a further experiment, the researchers tried to determine what

was driving the synesthesia. For the blind people with colored hearing, the meaning of a word, rather than its sound

alone, seems to be important. For example, when the word "March" was used in a sentence to mean a particular month

of the year, one volunteer saw a "dark greeny blue" color. But when he heard the same word used as a verb ("The

soldiers march across the bridge.") he did not see a color. Interestingly, when the same volunteer, who also has

colored-Braille synesthesia, read the number 1, the musical note A, or the letter A in Braille--all of which are

represented by a single dot in the upper-left corner--he saw the same color (white). His colored-Braille synesthesia

appears to depend on the pattern of the dots, not the semantic representation.

In the next step of their

research, Steven and her colleagues are using fMRI to investigate which areas of the brain in late-blind synesthetes

are activated during colored-hearing and colored-Braille.

[DrSmellThis]

I haven't read the article

yet, but I've known this forever. "Synesthesia" is the name for overlapping sense experience. It's been thought of

as a mental illness symptom until just recently. Actually it is just evidence of more highly developed sensory

perception and higher intelligence, IMO. Creative types tend to notice it more, but everyone has the capability of a

rich, overlapping sensory experience. Holistic phenomena such as this are one reason why I detest reductionism in

the study of perception (e.g., effectively reducing the phenomenon of attraction to one aspect of one sense, without

detailing or acknowledging the existence of other aspects and their relations as a whole) or any other field.

Willing reductionism is the love of stubborn ignorance. One of the key characteristics of the history of

science is the reliable tendency to find interactions between parts of a system formerly thought of as separate.

This is one of the main general insights the world has given us, in other words. Why people don't just

start from the baseline assumption of a holistic systems view is beyond me. This perceptual phenomenon is the

kind of situation that teaches that wisdom (the understanding of wholes or bigger pictures) and science cannot be

separate, without rendering each meaningless.

Wisdom is no stranger to these insights. In Eastern spiritual

traditions, the "third eye" or the "sixth chakra" represents the place just above the eyebrows and behind the

forehead where the senses come together. I wouldn't be suprised to find a correlation in the neurology of it. In

fact, I expect it will happen. So humanity has known of this for many centuries, and science is catching up

gradually.

I'll post again after reading the article.

[DrSmellThis]

OK, I'm back. Just as I

suspected, the perception research is just confirming what holistic thinkers have long known. The study grossly

underestimates the prevalence of synesthesia, though. I predict we'll soon find that everyone has it, and that it

isn't an "odd condition" in the slightest. It's just how our senses work. I'm quite sure of it, due to my own

pervasive synesthesia, and that of friends who have been exploring it with me; as well as psychological

observations.

Like synesthesia is for the senses, meanings and thoughts overlap among themselves in the same

way (e.g., in metaphor, myths or symbols, but also in more mundane ways. Another way of approaching it is to say

that the brain is analog as well as digital.).

I want to repeat that holism is the simplest and most basic

rational assumption to first approach any investigation with, or even one's own world with, as nature is

fundamentally systemic! This is just a basic principle of wisdom, or smart thinking. To reject this principle is

to love foolishness and become a black hole for it.

Is this insight relevant to the study of pheromones,

olfaction and attraction? You better believe it! Anyone who reviews the history of my posts on any serious topic or

debate, could notice this principle being implicit in my positions somewhere.

Unfortunately, most people don't

think of thoughts or ideas as the most powerful planetary forces. But the ignorance of the holistic principle

is one of the fundamental destructive forces in the world today! I'd be happy to try to demonstrate it with

regard to any field or endeavor. Everyone needs to wake up to this as soon as possible, especially young people and

parents. Things are related, and work together within larger systems or entities. If you want your kids to grow up

to be wise, teach them this! Everyone in the philosophy of science or general philosophy fields has a responsibility

to resist reductionism, as does anyone who respects wisdom. This is a big reason why I resist reductionism from JVK

and others so tenaciously. It's literally very destructive. (For example, to illustrate this to yourself, compare

the idea of attraction in the healthiest relationships, to that propagated by "quasi-scientists" who misleadingly

portray pheromonal reductionism as if it's supported by science as a whole; and as if it fairly represents

attraction. What would your relationships be like if you truly conducted them all by this reductionistic idea of

personal attraction alone? I'll suggest they would suck; for want of wisdom.).

[bjf]

I figured this would invoke great

debate on the visual & olfactory view of sexualty vs. Kohl's olfactory theory. There is something that has to be

looked at: is this interactin inate (being possessed at birth) or do the senses function indepently at birth, and

learn to work together? My intitution tells me a lot of the interaction is learned.

[DrSmellThis]

I think your intuition is

fundamentally backwards, though also correct in a sense. We grow in our holistic perception like anything else. But

the brain is fundamentally holistic, not a collection of distinct, mutually alienated, and independent facilities.

Think of how a fetus starts. Differentiation is what happens later or with time throughout nature. It is a

fundamental principle of development in nature. The stem and trunk always preceeds the branches.

Again,

think about the "analog vs. digital" analogy.

[bjf]

What I have in bold in the article -

does that explain a biological basis for better looking people having more success with pheromones? If the visual

stimuli goes with the pheromonal stimuli, the brain amplifies the information?

[DrSmellThis]

That would be a good "bottom

up" explation of it. A more "top down" view would be that "attraction" is a pervasive story people tell themselves;

tell each other; and create among themselves over time. The more aspects of the story hold true or fit together, the

more the attraction story becomes tellable and resonates. The brain amplification is really just like a sort of

harmonic resonance where more things fit together to make a coherent perception in an area of the brain where the

perception is being integrated as a candidate for a perceivable phenomenon (i.e., an experience of attraction). The

brain is like a meta-sense organ, then. It senses the phenomenon, or attraction, per se, as a whole!

This fits in perfectly with common sense and ordinary speech as well as science. So perception is like

meta-sensation, or a hierarchically bigger system into which sensation fits. Cognition, then, is like a

"meta-perception". (Culture is a more inclusive level still.) And it's all just reflective consciousness or

awareness, which just differs according to the degree of reflectiveness (though sensory information is really a

"pre-experience" before it is integrated in perceptual areas of the brain and becomes reflected upon in a basic way.

Otherwise it's just a meaningless incoming signal. Not all incoming signals are meaningless, however, as we're

consciously directed toward picking up signals and making sense of them already. A portion is never focused on by

immediate intentional consciousness but is processed less directly in the brain, put together, and "reflected upon"

somewhat below awareness). See how easily it all fits together when you look at it holistically or systemically?

There is no need to think in "fragments" whatsoever! It's more about general, real-world wisdom as opposed to "my

great theory," and yet all the science fits -- even moreso!

[DrSmellThis]

I figured this

would invoke great debate on the visual & olfactory view of sexualty vs. Kohl's visual theory.

As I've said

a dozen times in the forum, it's not about "visual versus olfactory" at all! When JVK paints it that way he

effectively compares one indefensible reductionism to another, thereby keeping his own position "safer;" by choosing

a weak, imaginary "enemy". The so-called "visual model of attraction" is a Quixotic paper windmill that can always

be "defeated" (Here I'm not saying there is no path from vision to potential attraction, as I'm sure there is).

There's no need to stop that war, I guess, or move onto a more fundamental one, when you are a Quixotic hero in the

war you're already in.

It reminds me of politics, another field where destructive reductionisms rule.

[bjf]

This whole issue reminds me of the

studies - I think on A-1 - where the women reacted to the substance only if the man was wearing it.

But then

again, we've had cases on the forum where women have sniffed pheromones straight out of the bottle and become

horny.

[bjf]

That would be a

good "bottom up" explation of it. A more "top down" view would be that "attraction" is a pervasive story people tell

themselves; tell each other; and create among themselves over time. The more aspects of the story hold true or fit

together, the more the attraction story becomes tellable and resonates. The brain amplification is really just like

a sort of harmonic resonance where more things fit together to make a coherent perception in an area of the brain

where the perception is being integrated as a candidate for a perceivable phenomenon (i.e., an experience of

attraction). The brain is like a meta-sense organ, then. It senses the phenomenon, or attraction, per

se, as a whole! This fits in perfectly with common sense and ordinary speech as well as science. So perception

is like meta-sensation, or a hierarchically bigger system into which sensation fits. Cognition, then, is like a

"meta-perception". (Culture is a more inclusive level still.) And it's all just reflective consciousness or

awareness, which just differs according to the degree of reflectiveness (though sensory information is really a

"pre-experience" before it is integrated in perceptual areas of the brain and becomes reflected upon in a basic way.

Otherwise it's just a meaningless incoming signal. Not all incoming signals are meaningless, however, as we're

consciously directed toward picking up signals and making sense of them already. A portion is never focused on by

immediate intentional consciousness but is processed less directly in the brain, put together, and "reflected upon"

somewhat below awareness). See how easily it all fits together when you look at it holistically or systemically?

There is no need to think in "fragments" whatsoever! It's more about general, real-world wisdom as opposed to "my

great theory," and yet all the science fits -- even moreso!

Well, I think the issue here is, does

LH response --> attraction. If it doesn't, then we've got to examine more inputs.

[Holmes]

the "third eye" or the "sixth chakra" represents the place just above the eyebrows and behind

the forehead where the senses come together. I wouldn't be suprised to find a correlation in the neurology of it.

The "third eye" area is connected to the pineal gland, yes?

[DrSmellThis]

This whole issue

reminds me of the studies - I think on A-1 - where the women reacted to the substance only if the man was wearing

it.

But then again, we've had cases on the forum where women have sniffed pheromones straight out of the bottle

and become horny.

That was referring to the presence of a man, but not the man necessarily wearing it, BTW.

But, yeah, good logic!

[DrSmellThis]

Well, I think the

issue here is, does LH response --> attraction. If it doesn't, then we've got to examine more inputs.

This

is a very nice observation, but that is only one such issue -- whether or not there's a significant change in

real attraction at all. Others include (A) what percentage of real world attraction can be accounted

for by (1) that particular LH spike; (2) LH spikes in general; and (B) To what extent would those

hypothetical percentages refer to true a causal force (remember that correlation does not = causation) if

they existed. Remarkably, none of these five absolutely critical scientific issues have been addressed, or even

acknowledged as issues, except here in the forum by folks like you or myself. To not do so would be both

unprofessional and unscientific.

[DrSmellThis]

The "third eye"

area is connected to the pineal gland, yes?

Yes. In Eastern traditions, the pineal gland has indeed been

thought to have a pivotal role. We of course don't need to restrict ourselves to their neuroendocrinology, though

we ought to consider it as a set of possible hypotheses.

[CptKipling]

There was a program about this

on the BBC's Horizon program, very interesting stuff.

I'm posting a link to the "searched" page because it

turned up a few interesting results, but the Horizon link is the first link.



http://www.bbc.co.uk/cg

i-bin/search/results.pl?tab=allbbc&go=homepage&q=synesthesia

They suggest that every human is a synesthese

to some degree, which may have been the origin of language. Also, the implication of synesthesia in creativity and

imagination was brought up, as well it's use in analogy and metaphore. I have noticed these things in myself

previously, e.g pain can "feel" red, or kind of icy blue.

[einstein]

I believe that classical

composers try to create this effect. Stimulating other sense from sound.

Evidence of synestese, found in a

different thread yesterday, from college student. I usually find myself comparing smells to tastes rather than

sounds. This could also be due to our lack of smell vocabulary.

I think the scent is an acquired

taste. I thought it was a bit feminine (spelling?) when I first got it. The scent from the gel packs seem to be

better in my opinion. The bottle just seems to have more of a higher pitch to the scent than the

gel.

I also remember an interesting article on this in Scientific American a few months ago. They were

talking about how some people see numbers as colors. Normal people, if you look at a paper covered in numbers or the

same font and size and color, it just looks like a jumble of numebrs. We can't look at it and instantly pick out

the 4's. But if we look at a paper covered in numbers with all the numbers black axcept the 4's are red, its easy

to pick out. A synesthese who sees numbers as colored could look at the all black number paper and instantly see a

certain number. The scientists used this as proof that its a real thing, not just an associated memory.

[DrSmellThis]

Nice posts, Kip and Einstein.

[writerguy]

Synesthesia. Now I know what it's called.

I've experienced it when I'm cooking -- as I taste a sauce I

often see in my mind's eye an organic-looking three-dimensional bar-graph-type representation of the tastes in my

mouth. About the time my sense of taste recognizes a missing ingredient, the bar graph shows the missing area, and I

just "know" that its a drop or two of lemon juice.

I thought it was just a 20-year-old bonus from some

mescaline I did in the 70s, but now I know I'm a synesthete.

As far as being a symptom of mental illness, my

wife would agree. I told her about the sensation and she looked at me funny for days. Like she didn't know

already...

[DrSmellThis]

Synesthetes, post your

experiences here!

[CptKipling]

Some thoughts:

I wonder if

synesthesia has anything to do with the process where you manipulate 3D objects/scenes in your head. I hear that

some are better at it than others...

Is synesthesia is why multi-sensory input is easier to learn from and

remember?

[DrSmellThis]

Is

synesthesia is why multi-sensory input is easier to learn from and remember?

Interesting hypothesis. I'd

guess there'd be synesthetic factors that influence learning and memory. It would be easy enough to design a study

to find out.

The (bodied) mind works mainly with present, remembered and imagined narrative; as well as salient

aspects of these narratives in abstracted form. Consciousness records itself in analog form (our minds/bodies are

like the "wax" or plastic an LP is made of, though there are also more "digital" characteristics.) and manipulates

it's record in many ways. Phenomena of experience, stories, and meaningful moments are the "mental units". I

believe there are corresponding brain structures, functions and activities for these experiential units. These

mentations are holistic. They "are what they are" in all their rich aspects, and our bodies (brains) reflect them

analogously, in real time, in imagination, and in memory. When a memory has multiple sensory aspects to it,

it's in good narrative form, and more natural for the nervous system to record, recall, generate, and process it;

in it's "analog way". The point isn't the sense or sensory data; which is secondary; but is rather the experience,

together with all our recursive reflections on it. Reflective experience is the fulcrum of mental activity. Meanings

are created by one's mind from the "stuff" of memory, imagination, sensory input, and intention; and constrained by

one's world.

[jvkohl]

Well, I think the issue

here is, does LH response --> attraction. If it doesn't, then we've got to examine more

inputs.

Among biologically based behavioral development specialists, I'm certain that anyone who has

studied mammalian behavior would agree that the LH response does lead to/correlate with attraction. In other

mammals, the LH response is critical for properly timed reproductive sexual behavior. Same sex pheromones retard the

LH response, opposite sex pheromones prompt it (with predictable behavioral correlates). With regard to all other

mammals studied, pheromones cause an LH response, and the LH response is readily and repeatedly linked to behavioral

change (typically change in sexual behavior). With regard to humans, DRSMELLTHIS frequently asserts that (the LH)

correlation is not causation, and that making any of the cause and effect assertions I have made is reductionism.

Here's a link to the diagramatic model of this reductionism.



http://evolution.anthro.univie.ac.at...ronic/kohl.jpg

I've seen no indication that

DRSMELLTHIS comprehends this model, or that he is willing to offer any other mammalian model as a basis for any of

his assertions. For all we Forum members know, DRSMELLTHIS has never published or presented anything to the

scientific community--much less established himself as a behavioral development specialist. But I consistently read

the pot-shots he sends my way. For example:

Everyone in the philosophy of science or

general philosophy fields has a responsibility to resist reductionism, as does anyone who respects wisdom. This is a

big reason why I resist reductionism from JVK and others so tenaciously. It's literally very destructive. (For

example, to illustrate this to yourself, compare the idea of attraction in the healthiest relationships, to that

propagated by "quasi-scientists" who misleadingly portray pheromonal reductionism as if it's supported by science

as a whole;...

I have fully detailed all aspects of the pheromonal conditioning of the biological

response most closely linked to properly timed reproductive sexual behavior. And I have extended "pheromonal

conditioning" to human sexual behavior via citations to numerous human studies. If anyone thinks that any critical

issue has not been addressed in extension of this mammalian model to humans (humans are mammals) they are uninformed

(and need only examine my published works).

Pheromonal reductionism is fully supported by biological

science--I have never indicated that it is supported by science as a whole--since that degree of support would

require other scientists to learn more about biology; something that most people involved in the philosophy of

science, or involved in general philosophy have little or no interest in doing. "Quasi-scientists?" In a recent

post, I called attention to Nobel Laureate Richard Axel's link to my website: . Richard along with

Linda Buck share the Nobel prize in medicine this year, and are now studying aspects of pheromonal communication.

The link (from other scientists) speaks for itself, biologically. Personally, I could care less what any

philosophers have to say about a biologically based model that also speaks for itself. But, from time to time, it

has become necessary to respond to the misrepresentations/attacks that DRSMELLTHIS continues to make in this Forum.

The article that was being discussed clearly supports pheromonal conditioning of visual input when it comes to

physical attraction; there is no biologicallly based mammalian model of visually perceived physical

attraction.

JVK