8 July 2005
A Penny for Your Qualia
By Rusty Rockets

The word qualia accounts for the subjective sensation experienced by a person when they see a color or eat an ice cream. For a concept that is so simply explained it has caused much controversy and division among the science community. For example, are qualia quantifiable brain states or are they merely a matter of semantics? As an area of research, the study of qualia has predominantly been relegated to the domain of the philosophy of mind, where some of the greatest minds seem to be split on its definition or even if it exists at all. They had better make up their minds fast, because current research on subjective cognition in the field of neuroscience seems determined to drag the concept of qualia out from the shadows of philosophy of mind and into the harsh light of physical science. But even here results have been mixed, and collectively do not amount to a solid theory on subjective consciousness. Sure, they can compartmentalize certain brain functions, but they cannot provide an explanation of how these functions interact and give us self-awareness. For many scientists this last point is a non-issue, because they believe, at least theoretically, that the entire sequence of “seeing blue”, formulating the word “blue” and therefore experiencing “blue” can be physically mapped in the brain and by doing so science need prove nothing else to do with consciousness.

In his book Phantoms in the Brain (1999), Dr V.S. Ramachandran, Director of the Center for Brain and Cognition at the University of California, San Diego, states passionately that the: “need to reconcile the first-person and third-person accounts of the universe (the “I” view versus the “he” or “it” view) is the single most important unsolved problem in science.” For the moment, we can at least examine some of the research and experiments that may eventually be responsible for understanding human thought, emotion and consciousness, and perhaps shed some light on the elusive questions surrounding qualia.

Simply looking at specific components of the brain is not sufficient to understanding or quantifying qualia. This “would be no more useful in understanding higher brain functions like qualia than looking at silicon chips in a microscope in an attempt to understand the logic of a computer program,” says Ramachandran. He believes we need to be able to see how the parts of the brain work in unison. Biologically speaking, seamless subjective experience seems to stem from the brain synchronizing “patterns of nerve impulses,” which then give rise to self-awareness.

UCLA researcher Dr Itzhak Fried and co-researcher Christof Koch, from Caltech, had a study published in Nature that presented results from an experiment that involved extracting data from consenting human subjects via intracranial electrodes. At the time Fried stated that: "Our ability to record directly from the living brains of consenting clinical patients is an invaluable tool for unravelling neural mysteries more efficiently and accurately." Fried’s experiment revealed that when a person looked at an image, in this case the image of Halle Berry, a specific brain cell would be activated. Pictures of actress Halle Berry activated a neuron in the right anterior hippocampus of a different patient, as did a caricature of the actress, images of her in the lead role of the film Catwoman, and a letter sequence spelling her name.

This led the researchers to believe that specific cells were alone capable of recognition, something that was counter to current thought. But sometimes the same brain cell would respond to images of other people. This may mean that there is not necessarily a Halle Berry brain cell that develops, but rather a cell that recognizes certain characteristics of Halle Berry rather than the whole person. Perhaps the cell recognizes Berry’s body shape, and all people that share a similar body shape to Berry activate that particular neuron. This would explain why the same cell would register for a number of different people, and is also consistent with the idea that neurons synchronize with other neurons to give a whole impression of a person. For example, Ramachandran discusses the condition called Capgras, where a patient thinks that that their parents or other significant people are in fact imposters. Something in the neural synchronization is missing, perhaps emotion, smell, or vocal aspects.

In a study conducted by Garrett Stanley at Harvard University, Stanley and his team used a cat’s brain to record signals from a total of 177 cells in the lateral geniculate nucleus - a part of the brain's thalamus - as they played 16 second digitised (64 by 64 pixels) movies of indoor and outdoor scenes. To truly measure qualia scientifically would require an experiment such as Stanley’s, where a number of people are subjected to the same controlled visual event and then have their thoughts ‘recorded’ and their responses and reactions compared to see how they each experienced the event. In fact, both Stanley and Itzhak’s research is developing along the lines of one of the classic arguments against the concept of qualia remaining a solely individual experience. Ramachandran refers to this as the “colour-blind superscientist” argument.

In this argument, you are a superscientist with “full knowledge of the workings of the human brain”, but you are completely color-blind. As a superscientist, curious about the recognition of color, you examine a patient who can see color. After extensive examination of the subject you can “completely understand the laws of color vision (or more strictly, the laws of wavelength processing), and you can tell me in advance which word I will use to describe the color of an apple, orange or lemon,” explains Ramachandran. There are many thought experiments along these lines, but to many this still does not account for the concept of qualia. This is because although a scientist can thoroughly account for what color is, and show how the brain receives and processes color, it does not account for the ineffable experience of “seeing” a color.

So maybe philosophy should not be pushed to the sidelines just yet, as there still remain many questions to do with subjective experience. Think on this for a moment, if we do have the opportunity of knowing others’ thoughts, emotions and experiences, would those experiences then cease, by definition, to be qualia? It is not only a matter of experiencing someone else’s subjective thoughts, but also how you subjectively experience their subjective experience. For example, if two people looked at the color red, one might experience it differently because they associate red with a certain smell.

It seems that experiencing another’s qualia would only have the effect of producing yet more of our own qualia: my experience of experiencing another’s qualia. Conceptual quagmires such as this can perhaps only be fully unraveled by philosophers, but again we come back to the problem of semantics. Ramachandran holds that there is no barrier between subjective experience, and that there is “no vertical divide in nature between mind and matter, substance and spirit. Indeed, I believe that this barrier is only apparent and that it arises as a result of language.”

Further reading:

Dr Stanley’s vision page http://people.deas.harvard.edu/~gstanley/research_vision.htm

2 February 2008
The Rhythm (And Melody?) Of Life
By Rusty Rockets

Listening to music of any kind is an integral aspect of our lives, but is it a necessary aspect? There may be lots of folks who live without music, but scientific research shows there is much more to music than there is to other so-called leisure activities that we consider enjoyable.

Last week, a Systematic Review from The Cochrane Library revealed that therapists would soon be adding music to their arsenal of therapies to treat depression. One neuroscientist, Alan Harvey, goes as far as suggesting that music has an evolutionary basis in regard to the development of the human brain and how this development has subsequently shaped civilization. It's a suggestion that may explain why so many of us have such a passion for music, and why music therapies, at least anecdotally, seem to show so much promise.

At the recent Annual Australian Neuroscience Meeting in Hobart, Professor Harvey told attendees that music is not just something that sounds nice, but may have practical applications in fields such as education and therapy. "And yet it still seems a bit peripheral in medicine and in education because it's viewed as a luxury, something that's an add-on," he said on Australian Broadcasting Corporation radio recently. "I think [music is] actually core to our whole being, because it was there in the very beginning of us. Our founder population had music as well as language."

According to Harvey's theory, music is more than just an art and is essential to our make up. And he contends that it just could be responsible for the development of the human brain. But does that mean that music is still an essential aspect of our existence today, or – assuming that music once did have an evolutionary purpose – is music just a redundant evolutionary throwback, as some of Harvey's critics suggest? Answering questions such as this will probably comprise much of the book that Harvey, from the University of Western Australia, is planning to write about his controversial theory. A book that will show, one would hope, how music used in medicine has some foundation in science.

As Harvey freely admits, much of what he is proposing is nothing new; he's just piecing together an idea that cuts across a number of fields, such as evolution, neuroscience, and anthropology. As such, there are other researchers looking into how music can reveal insights, or be of practical benefit, in their particular field. Interestingly, many researchers have found that both music and language are inextricably linked in a fundamental way. In a study released in September of last year, Northwest University researchers wrote that music training has an all-encompassing holistic effect on how the nervous system processes sight and sound. As a result, the researchers reasoned that music training might be more important to verbal communication ability than other techniques, such as phonics.

"Audiovisual processing was much enhanced in musicians' brains compared to non-musician counterparts, and musicians also were more sensitive to subtle changes in both speech and music sounds," said Nina Kraus, Professor of Communication Sciences and Neurobiology and director of Northwestern's Auditory Neuroscience Laboratory. "Our study indicates that the high-level cognitive processing of music affects automatic processing that occurs early in the processing stream and fundamentally shapes sensory circuitry."

By identifying these multi-sensory traits peculiar to musicians, the researchers found that brain alterations resulting from exposure to music training affects the same communication skills required for both speaking and reading. "Musicians have a specialized neural system for processing sight and sound in the brainstem, the neural gateway to the brain," said lead author Gabriella Musacchia. But it was already well known that the pathway for multi-sensory processing originates in the brainstem, which is an evolutionary primeval part of the brain that has always been considered unmalleable. But in an exciting new development, the Northwestern researchers found that the brainstem exhibits much more plasticity than previously thought, and that it acts as a common pathway for both music and speech.

As a result, the researchers suggest that musical training could enhance literacy skills among children, or even help those with literacy disorders. "The study underscores the extreme malleability of auditory function by music training and the potential of music to tune our neural response to the world around us," said Kraus. It also begs the question of whether there is some merit to playing music to newborns. Furthermore, the Northwestern study provides some hope in regard to Alan Harvey's music theory, which claims that our link to music has evolutionary underpinnings. Previous findings show that children with literacy disorders also have brainstem transcription errors, which would suggest that Harvey might indeed be on the right track.

We need look no further than the tone-deaf, or amusic individuals, for further evidence that there is certainly a link between music and language processing in the brain. While your partner or family member may sound like a cat being strangled in the shower, they're at least enjoying their own musical mayhem. For someone who really is tone-deaf – roughly 4 percent of the population – music cannot be perceived in the way it is intended, nor create music themselves – music's just noise, and they find no pleasure in it at all.

Using neuroimaging, researchers from the Montreal Neurological Institute of McGill University found that amusic individuals had more gray matter in particular regions (namely the right interior frontal gyrus and the right auditory cortex) associated with processing musical pitch than did people who are not tone-deaf. "Overall, behavioral evidence indicates that congenital amusia is due to a severe deficit in the processing of pitch information. However, until now, very little was known about the neural correlates of this disorder," says lead author Dr. Krista Hyde.

Interestingly, Hyde's findings on musical disorders are also linked to a literacy disorder. "Specifically, we found that tone-deaf individuals had a thicker cortex (or gray matter) in particular brain regions known to be involved in auditory and musical processing. This parallels with what has been observed in the learning disability dyslexia, in which the cortex is thicker in areas of the brain involved in reading ability."

From these studies we have seen that music is not only integral to human enjoyment, but that music is linked to fundamental aspects of our cognitive make-up. In this respect, the multi-sensory training that music provides us with can be considered a vital bridge between how we perceive our environment and how we communicate what we experience to others. Perhaps this is why enjoying music with others can often be such a unifying experience.

28 February 2008
This Is Your Brain On Jazz
by Kate Melville

Using functional magnetic resonance imaging (fMRI), two scientists have discovered that when jazz musicians improvise, their brains turn off areas linked to self-censoring and inhibition, and turn on those that let self-expression flow. The joint research, using musician volunteers from the Johns Hopkins University's Peabody Institute, sheds light on the creative improvisation that artists and non-artists use in everyday life, the researchers say.

Reporting their findings in Public Library of Science (PLoS) ONE, the scientists, from the Johns Hopkins University's School of Medicine and the National Institute on Deafness and Other Communications Disorders (NIDCD), describe their curiosity about the possible neurological underpinnings of the almost trance-like state jazz artists enter during spontaneous improvisation.

"When jazz musicians improvise, they often play with eyes closed in a distinctive, personal style that transcends traditional rules of melody and rhythm," says Johns Hopkins' Charles J. Limb. "It's a remarkable frame of mind, during which, all of a sudden, the musician is generating music that has never been heard, thought, practiced or played before. What comes out is completely spontaneous."

Though many recent studies have focused on understanding what parts of a person's brain are active when listening to music, Limb says few have actually delved into brain activity while music is being spontaneously composed. Curious about his own "brain on jazz," he and a colleague, Allen R. Braun, of NIDCD, devised a plan to view in real time the brain functions of musicians improvising.

For the study, they recruited six trained jazz pianists and designed a special keyboard to allow the pianists to play inside a fMRI machine. Because fMRI uses powerful magnets, the researchers designed the unconventional keyboard with no iron-containing metal parts that the magnet could attract.

After recording baseline brain scans while the subjects played scales and memorized pieces of music, Limb and Braun then analyzed the brain scans as the musicians improvised their own tunes. Since the brain areas activated during memorized playing are parts that tend to be active during any kind of piano playing, the researchers subtracted those images from ones taken during improvisation. Left only with brain activity unique to improvisation, the scientists saw strikingly similar patterns, regardless of whether the musicians were doing simple improvisation on the C-major scale or playing more complex tunes with the jazz quartet.

The scientists found that a region of the brain known as the dorsolateral prefrontal cortex, a broad portion of the front of the brain that extends to the sides, showed a slowdown in activity during improvisation. This area has been linked to planned actions and self-censoring, such as carefully deciding what words you might say at a job interview. Shutting down this area could lead to lowered inhibitions, Limb suggests.

The researchers also saw increased activity in the medial prefrontal cortex, which sits in the center of the brain's frontal lobe. This area has been linked with self-expression and activities that convey individuality, such as telling a story about yourself. "Jazz is often described as being an extremely individualistic art form. You can figure out which jazz musician is playing because one person's improvisation sounds only like him or her," says Limb. "What we think is happening is when you're telling your own musical story, you're shutting down impulses that might impede the flow of novel ideas."

Limb notes that this type of brain activity may also be present during other types of improvisational behavior that are integral parts of life for artists and non-artists alike. For example, he notes, people are continually improvising words in conversations and improvising solutions to problems on the spot. "Without this type of creativity, humans wouldn't have advanced as a species. It's an integral part of who we are," Limb says.

In research that may lead to new therapies for children with autism and Asperger's syndrome, researchers from Northwestern University have found the first biological evidence that musical training enhances an individual's ability to recognize emotion in speech.

Reporting the findings in the European Journal of Neuroscience, the study's lead author Dana Strait explained that the more years of musical experience musicians possessed and the earlier the age they began their music studies increased their nervous systems' abilities to process emotion in sound. "Quickly and accurately identifying emotion in sound is a skill that translates across all arenas, whether in the predator-infested jungle or in the classroom, boardroom or bedroom," she noted.

The study involved measuring brainstem processing of three acoustic correlates (pitch, timing and timbre) in musicians and non-musicians to a scientifically validated emotion sound. The 30 subjects were right-handed men and women with and without music training who were between the ages of 19 and 35.

Study participants were asked to watch a subtitled nature film to keep them entertained while they were hearing, through earphones, a 250-millisecond fragment of a distressed baby's cry. Sensitivity to the sound, and in particular to the more complicated part of the sound that contributes most to its emotional content, was measured through cranial electrodes.

The researchers found that the musicians' brainstems lock onto the complex part of the sound known to carry more emotional elements but de-emphasize the simpler (less emotion conveying) part of the sound. This was not the case in non-musicians.

In essence, musicians more economically and more quickly focus their neural resources on the important - in this case emotional - aspect of sound. "That their brains respond more quickly and accurately than the brains of non-musicians is something we'd expect to translate into the perception of emotion in other settings," Strait said.

The authors of the study also note that the acoustic elements that musicians process more efficiently are the very same ones that children with language disorders, such as dyslexia and autism, have problems encoding. Strait suggests that musical training might help promote emotion processing in these populations.