American Synesthesia Association

Vanderbilt University
Presentation Schedule and Abstracts

The Eighth Annual National Conference of the American Synesthesia Association at Vanderbilt University, Nashville, Tennessee.

Keynote Speaker

Julia Simner
Professor, Department of Psychology, School of Philosophy,
Psychology and Language Sciences
The University of Edinburgh, UK

Vanderbilt University Presenters and Abstracts

Bryan Alvarez, Department of Psychology, University of California Berkeley

Systematic global differences in the neuroanatomy of grapheme-color synesthetes: a DTI study

Bryan Alvarez1, Timothy Herron2, XJ Kang2, Kirstie Whitaker1, Lynn Robertson1,2, David Woods2
1University of California Berkeley, Berkeley, CA
2VA Northern California Health Care System

Grapheme-color synesthesia is a phenomenon in which graphemes (e.g., letters and numbers) trigger the automatic and consistent experience of color, and is the most studied form of synesthesia to date. In this study, the anatomical structure of the brain was compared between synesthetes and controls. Diffusion-weighted images were collected with a 1.5T MRI scanner to compare 20 grapheme-color synesthetes with 20 controls matched closely for age, handedness, years of education, and sex. All subjects also completed the Vividness of Visual Imagery Questionnaire (VVIQ) and 18 pairs of subjects completed the Ravens Advanced Matrices, a test of fluid reasoning. Two separate diffusion tensor analyses were performed to compare the neuroanatomy of fiber pathways between the two groups; a cortical surface-based analysis (FreeSurfer) and a deep fiber analysis (FSL). Systematic global differences were found between synesthetes and matched controls throughout much of the brain. These global differences also correlated with both the VVIQ and Ravens. This talk will discuss the implications of such findings and what they may suggest as to whether synesthetic differences are expressed in anatomically confined, phenomenologically specific regions, or more wide-spread regions of the brain.

Greta Berman, The Juilliard School, New York City

“Synesthesia: Art and the Mind” Two Years Later

Sponsored by McMaster Museum of Art, Hamilton Ontario, and co-curated by Carol Steen and myself, “Synesthesia: Art and the Mind” was not simply a one time phenomenon, but has continued to impact both scientific and arts communities. My paper will explore some of the reverberations from the exhibition, catalogue, and conference held at McMaster University in September, 2008.

From the scientific community:
A prominent psychiatrist, Michael Robbins, considers the catalogue a free-standing contribution, a central source for ideas about synesthesia, which he believes to be related to lucid dreaming. Both predispose toward “primary mental activity,” an important determinant of human behavior. A group from Weill-Cornell Medical Center held a joint meeting in March 2010 with Juilliard on Synesthesia, using these resources. Robert Zaller, noted historian at Drexel and synesthete, wrote that it is “unusual to learn something new about the plumbing of one’s own mind.”

Arts community:
Reviews of the show appeared in Leonardo, June, 2009. The London Telegraph mentioned the possibility that Van Gogh was synesthetic. A major Charles Burchfield exhibit toured the Hammer Museum, Los Angeles; the Burchfield-Penney Art Center, Buffalo; and the Whitney Museum, NYC from October 4, 2009 to October 17, 2010. Artist, Ellen K. Levy and I co-presented a well-received paper in Dublin, in October, 2009 at the International Art Critics Association conference, on “The Relations between Art and Science: Complicity, criticality, knowledge.”

Although exhibitions titled “Synesthesia” continue, they fail to distinguish between metaphorical and genuine synesthesia. “Synesthesia: Art and the Mind” remains the only one to date to focus on genuine synesthesia.

David Brang, Department of Psychology, University of California San Diego

Novel symbols show implicit associations in synesthesia

David Brang, VS Ramachandran
Department of Psychology, University of California San Diego

Grapheme-color synesthesia is a phenomenon in which letters and numbers consistently evoke specific colors (e.g. A=red). The neural basis of synesthesia has been thoroughly studied, and research suggests that the experience of colored letters arises from cross-activation between grapheme areas in the fusiform gyrus and neighboring color area V4. Synesthetes report that synesthetic colors often emerge for novel symbols after learning new linguistic scripts. However, as research suggests synesthesia implicitly activates colors at the component stage of letter processing (line segments, curves, etc.; Cascaded cross-tuning model of synesthesia), we suggest that synesthetic colors appearing after learning a new script were always present to some degree, and simply become unmasked and refined.

To test for the presence of latent color associations with novel symbols, synesthetes and controls were instructed to memorize predefined shape-color associations, operating on the assumption that the proscribed shape-color correspondences would on average differ from the implicit associations of any given synesthete. Complex, non-linguistic shapes elicited no conscious color association for any synesthete tested; further, each subject confirmed the shape did not resemble any conceptual or linguistic item they were familiar with. Results revealed synesthetes were significantly slowed and less accurate than controls in learning novel symbol-color associations, consistent with our suggestion that implicit form-color associations conflicted with the learned associations. Subject debriefing showed that while synesthetes initially had no preference on what color the shape “should” be, for some, the “true” color association would emerge after extended familiarity with the shape.

Olympia Colizoli

Can you teach yourself synesthesia?

Olympia Colizoli, Jaap Murre, Romke Rouw
Department of Psychology, Psychonomics, University of Amsterdam, The Netherlands

The most common type of synesthesia is grapheme-color. Why do some people develop this form of synesthesia and others do not? There seems to be a strong genetic component to synesthesia, yet the specifics of a language are acquired as we develop. Furthermore, synesthesia is a very heterogenous trait; the colors, feelings and strength of the experiences are different for each synesthete. It seems likely that there are latent synesthetes among us - people who may be synesthetic, but for some reason never formed conscious synesthetic associations.

Therefore, we investigated whether it is possible through training to show synesthetic behavioral effects as well as subjective experiences. We gave subjects books to read, in which four high frequency letters were matched with high frequency colors. Each person was asked about their preference for specific color-letter combinations, and the individual color-letter pairings were unique for each subject. A synesthetic-Stroop task was given before and after reading. A crowding test was given after the reading, comparing the letters which had been colored in the book to letters which had not been in color.

Results suggest that the synesthetic-Stroop effect is present in a subgroup of subjects after reading the novel. Reaction times on congruent stimuli correlate negatively with the number of words read in the posttest condition of the Stroop task. Subjects who read the book in color did significantly better on trained graphemes within the crowding task compared to a group of controls. No subjects reported seeing colors when viewing letters. A minority of subjects reported experiencing color when thinking about certain letters.

Future research will look at long-term effects of training. We will investigate whether the structural connectivity between grapheme- and color-specific areas increases due to reading in color, and whether structural or functional connectivity can predict a person's ability to learn the color-letter associations.

David M. Eagleman, Departments of Neuroscience and Psychiatry, Baylor College of Medicine, Houston, Texas

What has large-scale analysis taught us?

David Eagleman1,2
1Department of Neuroscience, Baylor College of Medicine, Houston, Texas
2Department of Psychiatry, Baylor College of Medicine, Houston, Texas

In 2006 we launched the Synesthesia Battery (, a free platform for screening and quantifying synesthesia. In the intervening years we have verified almost 10,000 synesthetes across 15 types of synesthesia and 8 languages. In this talk we will discuss some of the most important findings that have come to light from these data, as well as discuss present and future collaborative efforts. Moreover, combining these psychometric data with our parallel work in neuroimaging and genetics, we will argue that synesthesia is not a single phenomenon, but is instead an umbrella term that covers several different phenomena—all of which have in common an increased crosstalk between senses, but appear to be underpinned by different neural and/or genetic bases. Finally, we will present a new anatomical hypothesis that brings together scattered findings in the literature into a parsimonious framework.

Carrie Firman, Artist; University at Buffalo, New York

Multimedia Synesthetic Art

As an artist and designer, I find inspiration for my work in synesthesia. My creative process and goals involve the unfolding, authentic description, and sharing of the very real and beautiful nature of my synesthesia. My presentation will allow the audience to experience the work described below before my summary of its content and creation.

In an on-going synesthetic diary, I record my days with color or shape representing events and changes. In April I broke my leg, causing a traumatic shift in the appearance of my calendar. “Days of Captivity” is an interactive computer piece that maps my physical and emotional journey as I deal with pain, spend time with visitors, and cope with being dependent on a wheelchair through my recovery. It serves as a decoder to my synesthetic relationship with memory and time.

Long before breaking my leg, I began having increasing, unexplainable chronic pain throughout my body. The sharp amber and radiating red hues of pain led me to design a wearable work: “Sympathy Pains.” This retrofitted trench coat shares my pain and colors with its wearer through weight, pressure, and light.

I have begun a compilation of my synesthetic reactions to sounds. This 48-piece web library ( was the inspiration to create a floor that triggers sounds and projected images. Striving to make the synesthetic experience authentic and accessible, this walk-in piece, “Synexperience”, emphasizes the elements of unexpected triggering, consistent reaction, and discovery.

Laura Gibson, Department of Psychology, Neuroscience, and Behaviour, McMaster University

Sequence-Space Associations: Some Consistency even in Non-Synaesthetes

Laura Gibson, Daphne Maurer McMaster University, Hamilton, Ontario, Canada

A majority of both synaesthetes and non-synaesthetes perceive ordinal sequences on a mental “number” line that is oriented from the left to the right side of space (Dehaene et al., 1993; Sagiv et al., 2006). Although the consistency of sequence-space associations over time in synaesthetes is well-established, the reliability of these sequence-space mappings in non-synaesthetes has not been determined. We investigated the stability of these mappings for numbers, weekdays, and months of the year in 60 non-synaesthetes. Their task was to indicate whether an item on the screen was early (or late) in the sequence with a concordant hand (early signaled with the left hand; late with the right hand) or discordant hand (the opposite mapping), a procedure called the SNARC task. Participants were tested on two separate occasions 1-3 weeks apart. Pearson r correlations indicated that the size of the compatibility effect was modestly consistent across the two visits for numbers and months (both rs > 0.3), with a similar trend for weekdays (r=0.26). Thus, non-synaesthetes’ sequence-space mappings are consistent across time - albeit to a lesser extent than those of synaesthetes. These data support the hypothesis that syaesthetes and non-synaesthetes share a common cross-modal neural architecture linking ordinal sequences and space, differing largely in the ability of these connections to reach the threshold of conscious awareness.

Lynn Goode, Smith College School for Social Work; Artist; Houston, Texas

Synesthesia: A Sixth Sense or a Sensation?

Synesthesia is a peculiar neurological phenomenon that occurs when two senses combine. For example, seeing the colors of words, letters, and music or feeling the shapes of tastes and smells are types of synesthesia. Persons who experience these sensations are called “synesthetes.” I am one of a small percentage of the population who “see” language in color. Although writers, poets, and artists have historically intertwined color and language in a metaphoric way, letters and words literally appear in my mind in a color-coded sequence. While synesthesia is an involuntary, sometimes disruptive process for those who experience it, most synethetes cannot imagine living without the phenomena.

My research was undertaken by means of a constructed survey of persons with synesthesia to examine how the condition has impacted each subject’s life in terms of aversion to different colors related to traumatic incidents, physical and/or mental illness, psychotropic interventions (such as SSRI drugs), prevalence within gender, and color coded-memories. The paper discusses how medical and mental health professions can better understand the association between colors and the emotional effects pertaining to a particular color is it is associated with an unpleasant memory or traumatic event.

Lastly, because Synesthesia is defined as a cross-firing in the nervous system, a small portion of the survey asked participants to disclose if he or she had any neurological conditions that were prevalent within synesthesia population.

Helena Melero, Universidad Complutense de Madrid, Spain

Synesthesia in Spain: a combined neurophenomenological and neuroimaging approach

Melero, H.1, Peña-Melián, A.2, Ríos-Lago, M.3 and 7Aaxure;lvarez-Linera, J.4

1Department of Psychobiology, Faculty of Psychology, Universidad Complutense de Madrid, Spain
Department of Investigation, Development and Promotion, International Artecittá Foundation
2Department of Anatomy and Embriology of Human Nervous System I, Faculty of Medicine, Universidad Complutense de Madrid, Spain
3Department of Basic Psychology II, UNED
Brain Damage Unit. Beata Mariana Hospital, Madrid, Spain
Fundación Cien-Fundación Reina Sofía, Madrid, Spain
4Image Diagnosis Department. Ruber International Hospital, Madrid, Spain

Grapheme-colour synaesthesia is one of the most common types of synaesthesia and also the most studied one. However, its underlying neural mechanisms and developmental characteristics are still controversial. This study presents the first synaesthesia large-sample survey (up to 800 participants) conducted on Spanish population. It also presents preliminary neuroimage results of Spanish synesthetes. This work, using the neurophenomenological approach to complement neuroimaging data, aims to find room for the emotional component in explanatory models of synaesthesia in order to address it as the multilevel conscious experience it constitutes.

Samantha Moore, Director; Shropshire, England

Getting the picture: Digitally visualizing and animating synaesthesia

“To be honest, um, I see things really flowingly, ...within my head ... very flowingly, and forward moving, and really hard to describe...”

How would you describe synaesthesia to someone who doesn't know what it is? Every synaesthetic reaction is unique and yet there are similarities in the ways in which they are experienced. An Eyeful of Sound is a collaborative short film project completed in 2010 between synaesthetic people, researchers and film makers concerned with visually describing synaesthesia to a wider audience. It is an impressionistic portrayal of a synaesthetic person's everyday perceptions. The audience is given the scope of the synaesthetic responses, and an understanding of what it is like to see the world through these eyes. Synaesthesia is shown interacting with other more recognizable environments, like a street or a forest, but since the ‘real’ world and synaesthetic world are both animated they carry equal weight with the viewer, attempting to give a more psychologically realistic view of the condition.

Animation director Samantha Moore will talk about making the film and the problems and challenges in collating, verifying and realizing synaesthetic reactions into the form of animated film. To do so she worked with Dr Jamie Ward (University of Sussex), and synaesthetic interviewees Tessa Verrecchia, Emma Suddaby and Julie Roxburgh, as well as animators, producers and artists. This presentation will be illustrated by clips of the final film along with some of the process of animating synaesthetic responses.

Maureen Seaberg, Author, New York City

Why Synesthesia Matters Spiritually

Based on her presentation at the Towards a Science of Consciousness Conference in Tucson, Arizona in April (with updates from Dr. Pim van Lommel and Lama Za Rinpoche) this presentation is a survey of the many examples of synesthesia in religious thought and even present-day quantum philosophy. From 13th Century wisdom from the Zen Master Dogen, to a theory that synesthesia is the Buddhist “Mind Sense” at work according to modern-day scholar Dr. Robert Thurman, synesthesia has figured prominently in Buddhism, but also Christianity, Islam, Judaism, Mormonism and Theosophy. Further, Dr. Roger Walsh’s study on meditators proves that synesthesia can be acquired in meditation. And Dr. Stuart Hameroff, consciousness expert, declares that synesthesia is “a lower threshold to the quantum.”

Julia Simner, Department of Psychology, School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, UK Keynote Speaker

The Synaesthetic Continuum

Definitions of synaesthesias are based on a set of core facts: that a small percentage of the population report extra-ordinary sensations of colours, tastes, shapes etc., triggered by everyday activities such as reading, listening to music, eating, and so on. Synaesthetes might see colours when they hear sounds, for example (known as music-colour synaesthesia) or experience tastes in the mouth when reading or speaking (known as lexical-gustatory synaesthesia). These sensations are explicitly experienced in that synaesthetes are consciously aware of them in daily life; they arise spontaneously, without effort, and in ways that synaesthetes tends to accept as normal within their own realm of experience. Given this, synaesthesia is often defined by the fact that synaesthetes differ to the average person. In this talk, I'll question the strength of this 'synaesthetic divide', showing that in fact, all people experience systematic, detectable, sometimes inherited, cross-modal mappings across the senses. With work from my own lab and from others, I'll describe how synaesthetes and non-synaesthetes are similar, rather than different, and why this similarity is important. We'll see that studies on synaesthetes can inform us about the minds of non-synaesthetes, and vice versa, and that the existence of a 'synaesthetic continuum' across populations can provide us with answers about the very causes of cross-sensory processing in all people.

Marcia Smilack, Photographer; Martha's Vineyard, Massachusetts

Fonts and Other Voices: Personification in Synesthesia

There are certain fonts I’m a little afraid of while others exactly match what I need to say when I need to say it. What does this mean? Well, I could pick each font apart to offer graphic reasons why I have these emotional reactions – for example, that the shapes of the font Courier make me nervous (too many tiny spaces between black lines) whereas those of Comic Sans feel comfortable (no right angles to interrupt my thought). But are these answers really the point? The questions I’d rather answer are: why do I respond to fonts in the first place; to what degree is my Synesthesia responsible; and what role does personification play? I have multiple forms of Synesthesia. While colored graphemes is not one, I do respond to letters and numbers which have gender and personality, but that is not surprising considering that nearly everything I look at has gender and personality. I automatically personify what I see, a reaction perhaps most notable in my photography where I take pictures of reflections on water. I click the shutter when I hear a chord of color, feel texture on my skin or feel my body bend to the shapes. I also personify my subjects. The houses I take pictures of are never just houses. They are people while their windows are eyes. Is this reaction related to my reaction to fonts? I hope to answer that question along with the others in my presentation at the conference.

Mary Jane Spiller, University of East London, UK

Neuronal activity in response to hearing words: a magnetoencephalography (MEG) study of grapheme-colour synaesthesia

A. Asghar1,2, M.J. Spiller4,T. McGlashan2, V. Pironti2, S. Petty2, G. Green2, W. Woods2, A. Nevado2, M. Simpson2, M. Pulgarin2, J. Simner3 and A. Jansari4
1Hull York Medical School and Biological Sciences, University of Hull, Hull, HU6 7RX
2York Neuroimaging Centre, York University, York, YO10 5DG
3School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, Edinburgh, EH8 9AD
4School of Psychology, University of East London, London, E15 4LZ

Functional MRI neuroimaging studies have indirectly suggested neuronal activation of the brain’s “colour centre”, left visual V4 area, when grapheme-colour synaesthetes are presented with written or spoken graphemes. The current study used magnetoencephalography (MEG) scans to provide a direct measure of neuronal activity by recording external magnetic fields that were associated with neuronal currents in the brain when grapheme-colour synaesthetes (n=14) and matched controls were presented with spoken words. Magnetic fields were analyzed using a spatial filtering technique (beamforming) to find locations of neuronal sources within the brain; a comparison was made of the power amplitudes of the alpha and beta band rhythms before and after the auditory word stimuli in synaesthetes and controls. The results reveal changes in neuronal rhythmicity located in left V4 when the synaesthetes were presented with spoken words, consistent with previous functional MRI blood flow studies. Our results demonstrate a decrease in amplitude of the beta rhythm in left V4 and also bilaterally in V1/V2 in synaesthetes but not in controls. Our results show that MEG can provide novel information on the processing of grapheme-colour synaesthesia from neuronal sources that is not possible with other non-invasive neuroimaging techniques. It remains to be elucidated how the changes in neuronal activity lead to the synaesthetes’ conscious perception of colour in response to graphemes.

Carol Steen, Artist; Touro College, New York City

Do You See What I See: Synesthesia in Painting and Video

Despite intensive studies and research concerning synesthesia and synesthetic commonalities, there remain many questions about what synesthetic photisms really look like. One problem is that very few synesthetes have been able to accurately depict their synesthesia as it appears to them. The verbal descriptions and visual depictions of synesthesia, the combinations of lines, shapes and colors that are usually portrayed as beautiful words, as linear drawings, or as still paintings cannot show one of the most interesting aspects of some forms of synesthesia. The visions move. Until very recently, capturing synesthetic movements was difficult. But thanks to advances in technology, it is now possible to explore in video what moving photisms look like. We can observe their timing, how they move, appear, disappear and change. In my paper I will discuss what it’s like to create in different media, using my synesthesia. I will explore the differences between still and animated media: the limits of painting, and the possibilities of video.

Steffie Tomson, Department of Neuroscience, Baylor College of Medicine, Houston, Texas

Using neuroimaging and genetics to probe the neural mechanisms of synesthesia

S. N. Tomson1, M. Bray2, S. Leal3, D. M. Eagleman1
1Department of Neuroscience
2Department of Pediatrics
3Department of Human Molecular Genetics, Baylor College Of Medicine, Houston, Texas

One common form of synesthesia is characterized by an automatic perception of color in response to members of over-learned sequences such as letters, numbers, weekdays, or months. We call this form colored sequence synesthesia (CSS). To elucidate the neural activity underlying CSS, we used functional magnetic resonance imaging to localize grapheme- and color-sensitive brain regions in 17 synesthetes and 17 controls. A contrast of graphemes with scrambled graphemes revealed regions in right and left temporal lobes that are the same in the synesthetic and control groups. However, a contrast of colored stimuli and grayscale stimuli revealed that synesthetes have higher activity levels in occipital regions that traditionally encode color. We suggest the possibility that the more extensive color processing in synesthetes may anatomically position grapheme-sensitive regions closer to color-sensitive regions. This suggests a different basis for synesthesia beyond the traditional model of increased crosstalk between areas that are anatomically the same across synesthetes and controls. In a second step of the neuroimaging, we asked subjects to watch a grayscale, 12 minute, grapheme-rich video of children's television. This revealed a high correlation of the BOLD signal in the color areas across synesthetes (but not in controls), verifying our expectation that the graphemes in the video are entraining the activity in the color areas. Finally, to understand the molecular basis of the differences in synesthetic brains, we are searching for the genetic basis of this heritable condition. We present data from our ongoing family linkage analysis that implicates a region 23 megabase region on chromosome 16 which contains over 100 genes expressed in the brain. In summary, we are combining neuroimaging studies and genetic linkage analyses to sketch a coherent picture of the neural basis of synesthesia.