Cognitive Neurophysiology Laboratory

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Docs: Fast Free Recall

Updated on October 6, 2023

Running fast free recall for looking most effective stimulation protocol:

Preparation:

Decide on number of words to use. This should be greater than the number used in a typical verbal memory experiment, as the patient will have the opportunity to hear each word list 4 times. If a patient has been getting 4-5 words from a 10-word block, 16 is probably a good number.

Set up stimulation protocols. For the continuous protocols, the total length in seconds should be equal to the number of words. Template stim protocols are already defined in the stim computer. They are named after frozen desserts so that the patient won’t know what kind of stimulation they’re receiving.

  • Gelato is non-stim, so there is no corresponding stim protocol.
  • Ice cream is theta burst and is delivered at the beginning of each trial, so there is no need to adjust this protocol.
  • Fro-yo and sorbet are both continuous, and will be delivered as a single pulse either at the beginning of a block or halfway through it. You must adjust the number of pulses in these paradigms to make them the correct length. Fro-yo is 50 Hz continuous, sorbet is 100 Hz continuous.

Run:

Syntax is here: fastFreeRecall_stimType(patientNumber,nWordsPerSet,nRepsPerBlock,debugMode)

I recommend the following parameters, generally:

fastFreeRecall_stimType(patientNumber, 16,4,0);

Tell the patient that this is like verbal memory, but it’s going to go faster than usual and they’ll have more words. So it will be a challenge! But to make up for it, they will hear each set 4 times, so they can learn them.

The code will give you a chance to test TTLs and stimulation within it. Be sure the microphone is working as well, please!

After preliminary tests, it will start each block. It will show a screen and tell the patient to give you the magic word. There will be a magic code you must give them to type to continue. This allows you to set up the stim computer to be using the correct paradigm before continuing. Once you’re ready, give them the correct code. (Note, the codes should be intuitive to you, based on the type of stimulation.)

  • % gelato = non-stim = press ‘n’
  • % fro-yo = 50 Hz continuous = press ‘5’
  • % sorbet = 100 Hz continuous = press ‘1’
  • % ice cream = 100 Hz theta burst = press ‘t’

Beyond that, this runs just like verbal memory, except words are presented every 2 seconds instead of every 8. See/hear words, odd/even, recall stage. Repeat 4 times. New magic word…