Instructions for emma experiment

Unexpected Auditory Perturbation fMRI Experiment
General protocol:

Each run consists of the production of 8 repetitions of each of 8 words, along with 16 control trials, for a total of 80 trials, each 12 seconds long (total run time approximately 16 minutes). On 1/8 of the trials for each word the subject’s auditory feedback is shifted upward; on 1/8 of the trials it is shifted downward; on the remaining 6/8 trials it is unshifted. During the control trials, the string ‘yyy’ is presented on the screen instead of a word and the subject is instructed to sit quietly without speaking.

The aim is to collect 4 runs per session, time permitting. Before the start of each run, the experimenter should remind the subject to speak clearly.
Timeline for each trial:

T=0: Word (or ‘yyy’ for control trials) flashes onto screen and sound recording starts; subject instructed to start reading as soon as he/she sees word and to hold the vowel until the word disappears;

T=2s: word disappears;

T=3.5s: recording stops and signal is sent to DSP board to stop auditory feedback;

T=5s: scan starts;

T=9s: scan ends (collect two TRs);

T=10s: signal to DSP board to start auditory feedback;

T=12s: next trial begins.

If the volume of the subject’s voice is too low on a given trial, a note will appear on the screen immediately after that trial telling the subject “Please speak louder.” The note should be in a different text color than the words, and perhaps a smaller font, so that the subject doesn’t start to read it aloud. The note should stay up for 3 seconds. The next trial should start 5 seconds after the note goes away.
Stimulus set:

• 
  beck
  
• 
  bet
  
• 
  deck
  
• 
  debt
  
• 
  peck
  
• 
  pep
  
• 
  ted
  
• 
  tech
  

Instructions for subject:

While you are in the scanner, words such as “bet” or “ted” will appear on a screen in front of you. As soon as a word appears, we would like you to pronounce it slowly and clearly. It is very important that you try to speak clearly throughout the experiment. The experimenter will give you examples of each word and will have you practice the pronunciations before the experiment starts.

The words will contain a vowel in the middle. Please try to hold the vowel until the word disappears. For example, if the word “bet” comes up, say “beh” and continue the “eh” sound until the word disappears, then finish the word by saying the “t”. In other words, say it like “beeeeeeeeeeeht” with the “t” coming right after the word disappears from the screen.
Occasionally, the string “yyy” will appear on the screen instead of a word. In these cases, do not attempt to pronounce the string; just sit quietly until the next word comes up on the screen.
You should speak at a normal volume level throughout the experiment, as if speaking to the experimenter through the microphone. The experimenter will instruct you on this before the experiment starts. If your speech becomes too quiet during the experiment, you will see a note on the screen asking you to speak louder. The note will then disappear and the next trial will begin after a few seconds. Just sit quietly after reading the note (do not read it aloud or repeat the previous word) and wait for the next trial to begin, then speak a bit louder (but don’t yell) for the remaining trials.
The experimental session will consist of 3-4 runs, each approximately 16 minutes long. For all runs, be sure to move your mouth only when pronouncing the words and refrain from any other head movement at all times. It is very important that you make no unnecessary movements during a run. If necessary, you may move your arms or hands after the experimenter notifies you that a run has ended, but be sure to never move your head and keep any other kind of movement at a minimum even while the scanner is not running.