Learning and memory may play a central role in synesthesia

People with color-grapheme synesthesia experience color when viewing written letters or numerals, usually with a particular color evoked by each grapheme (i.e., the letter 'A' evokes the color red). In a new study, researchers Nathan Witthoft and Jonathan Winawer of Stanford University present data from 11 color grapheme synesthetes who had startlingly similar color-letter pairings that were traceable to childhood toys containing magnetic colored letters.

Their findings are published in Psychological Science, a journal of the Association for .

Matching data from the 11 showed reliably consistent letter-color matches, both within and between testing sessions (data collected online at http://www.synesthete.org/). Participants' matches were consistent even after a delay of up to seven years since their first session.

Participants also performed a timed task, in which they were presented with colored letters for 1 second each and required to indicate whether the color was consistent with their synesthetic association. Their data show that they were able to perform the task rapidly and accurately.

Together, these data suggest that the participants' color-letter associations are specific, automatic, and relatively constant over time, thereby meeting the criteria for true .

The degree of similarity in the letter-color pairings across participants, along with the regular repeating pattern in the found in each individual's letter-color pairings, indicates that the pairings were learned from the colored letters that the participants had been exposed to in childhood.

According to the researchers, these are the first and only data to show learned synesthesia of this kind in more than a single individual.

They point out that this does not mean that exposure to the colored letter magnets was sufficient to induce synesthesia in the participants, though it may have increased the chances. After all, many people who do not have synesthesia played with the same colored letter magnets as kids.

Based on their findings, Witthoft and Winawer conclude that a complete explanation of synesthesia must incorporate a central role for learning and memory.

Related Stories

Brain study explores what makes colors and numbers collide

Nov 17, 2011

Someone with the condition known as grapheme-color synesthesia might experience the number 2 in turquoise or the letter S in magenta. Now, researchers reporting their findings online in the Cell Press journal Current Biology on Nov ...

Why has synesthesia survived evolution?

Nov 22, 2011

In the 19th century, Francis Galton noted that certain people who were otherwise normal "saw" every number or letter tinged with a particular color, even though it was written in black ink. For the past two decades researchers ...

New research shows consistency in synaesthetic experiences

Apr 29, 2008

A quirky psychological phenomenon known as “grapheme-color synaesthesia” describes individuals who experience vivid colors whenever they see, hear, or think of ordinary letters and digits. A hallmark of synaesthesia ...

Researchers find that hypnosis can induce synesthesia

Oct 23, 2008

Hypnosis can induce "synesthetic" experiences – where one sense triggers the involuntary use of another – within an average brain, according to a new study in the journal Psychological Science, the premiere publication of the ...

Recommended for you

Could summer camp be the key to world peace?

6 hours ago

According to findings from a new study by University of Chicago Booth School of Business Professor Jane Risen, and Chicago Booth doctoral student Juliana Schroeder, it may at least be a start.

Gender disparities in cognition will not diminish

Jul 28, 2014

The study, published in the Proceedings of the National Academy of Science, investigated the extent to which improvements in living conditions and educational opportunities over a person's life affect cognitive abilities and th ...

Facial features are the key to first impressions

Jul 28, 2014

A new study by researchers in the Department of Psychology at the University of York shows that it is possible to accurately predict first impressions using measurements of physical features in everyday images of faces, such ...

User comments