The overall goal of the following experiment is to train letter color associations by reading in color and to measure the effects of training in the brain. This is achieved by first testing participants in the behavioral lab and in the MRI scanner before they start the training. The next step involves having the participants read specially prepared colored books for several weeks outside of the lab.
Finally, the participants repeat the same experiment in the behavioral lab and in the MRI scanner in order to measure any training effects of reading in color. Results show the overall effect of reading in color on reaction times and brain function using a letter. Color Stroop task ask.
The idea for this method came about because when I give talks or presentations, people often come up to me and say, can I learn synesthesia? And this whole experiment is directed at solving that issue. The main advantages of reading in color compared to computer based training programs are that any text can be colored.
Participants can choose whatever book they'd like to read, and they can also read for as long as they would like. This method will help us understand to what degrees in anesthesia can be learned, and this is important to answer questions that are key in the field, such as the neural basis of visual learning and visual memory. After screening for any covariate traits in study participants assess their motivation for taking part, inform them that they must be willing to read outside the lab for the study, but it may be whatever material they choose to test.
For the presence of synesthesia, use a consistency test. Give a questionnaire or computer-based test retest. Paradigm verified.
Online testing services are another option. If the protocol includes MRI, be sure to also screen participants. For MRI Associated health risks, I ideally, participants should be willing to read daily for as long as they can.
Choose four relatively frequent letters for the reading language of the participant. Ideally, choose two letters that are very frequent and two that are less frequent, but not uncommon. To each of the four letters, assign a clearly distinguishable color.
Print the reading material in the blocky font, aerial black 10 point font. In this case, only the lowercase letters are colored. Precisely match the colors in the printed material to the colors on the monitor.
Used for the testing sessions, have several people verify these settings. The testing room must have controlled lighting conditions and hence lack windows. Using a five point Likert scale, ask the participants to rate their preferences for the 16 combinations of the four letters with the four colors, preferred letter color pairs are defined as a rating of three to five.
Non-preferred letter color pairs are defined as a rating of one to three. The three rating is included in both groups. Conduct the study to test for an interaction between letter frequency and letter color.
Pair preference for half of the pool. Assign the two more frequent letters to preferred colors and the two less frequent letters to non-preferred colors. The other half of the participants get assigned the reverse based on the letter color assignments.
Prepare the books in Microsoft office word using a visual basic macro. Replace each instance of a certain letter with the assigned font color. Instruct the participants to record how many pages they read and for how long.
For inclusion of the data in the study. Decide on a minimum criteria for reading volume before testing begins. When the trials are all completed, give the participants a subjective questionnaire on reading in color to give color key training.
Show squares of the four colors one at a time in a random order. 48 times per color. Instruct the participants to type the correct key as quickly as possible.
Give feedback after each trial for accuracy and a short break. Halfway through the training, the participants must finish with greater than 95%accuracy and type results quickly without looking at their fingers. Repeat the training sessions until this goal is obtained.
Once properly trained, administer the stroop task. Compare 48 congruent color letter conditions with 48 incongruent. Color letter conditions per testing session.
Ask the participants to indicate the color of the letter presented as quickly and accurately as possible. Each trial consists of showing one of the four letters in black for 200 milliseconds, followed by that same letter presented in one of four colors until a response is made or two seconds pass. Letters are always centered on a white background between trials show a fixation cross for a random duration between one to two seconds.
Accuracy, reaction, time, and missed trials are all scored, but the participant should get no feedback during the task. However, provide at least one breakpoint. Administering the Stroop test in the MRI is similar to giving the test in the lab.
It is still an event related paradigm and not a blocked design. Use the same number of total trials randomly pressing an equal number of congruent and incongruent stimuli. Unlike in the lab, the colored letters remain on screen for two seconds per trial and are not removed from the screen.
With the button press, be sure that the participant is aware of this difference. Also, unlike the lab fixation, cross durations are also randomly assigned to each trial. However, a different set of durations are used for the MRI experiment.
During the test independently verify that the participant's responses are being logged correctly. Also split the Stroop task into two separate runs in order to avoid fatigue related performance decline in the scanner, learned associations between colors and letters were measured by the stroop effect before and after reading the colored books. A significant interaction between the testing session and congruency conditions would indicate that letter color associations changed due to reading in color.
If a significant interaction between the letter color preference groups and the stroop effect is found, then preexisting preferences for colored letters interacted with the frequency of the letters presentation as seen here. Brain imaging analysis of participants with learned letter color association revealed brain activation in the post reading brain imaging session. This data from one participant in one testing session shows where there was significantly more activation during the presentation of one condition compared to the other.
The reading and color training method is unique compared to other methods because the letter color associations are formed as a natural byproduct of the reading process and don't need to be rehearsed explicitly. Finding a synesthetic STR effect does not necessarily mean that the trainees have genuine synesthesia. It does show that they have learned associations, and these are strong associations, but finding a strip effect does not necessarily imply that the associations are at the perceptual level.
So other tests, for example, memory tests or reading speed tests can be easily combined with the current protocol in order to answer additional interesting questions such as, does reading in color improve your memory for letters or numbers? And does reading in color increase the speed of your reading?
