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Brain picture
Beauchamp Lab

To search for things on the wiki, use Google's site search feature. For instance, to find an Experiment Sheet, type ExperimentSheet

The first step is to define the "S" data structure. Here are the components of the S data structure:

                fileName: {'YAODatafile017'  'YAODatafile018'}
             chanDesList: {1x68 cell}
                  images: 8
              imageNames: {6x1 cell}
                 kStimOn: 80
               kImageMin: 4096
    kResponse_leftbutton: 128
   kResponse_rightbutton: 129
                      Fs: 2000
               startTime: 0
              sampleTime: 0.5000
         trialTimeCourse: [1x8000 double]

Here are what the elements of the data structure represent:

  1. filename: Name of the raw data file. Each session of an experiment is recorded in a separate datafile.
  2. chanDesList: List of electrodes written according to the montage.
  3. images: Number of different stimuli (conditions) presented in this experiment.
  4. kStimOn: Stimulus onset. The onset of each presented stimulus is registered as an event. Stimulus onset events are always denoted by 80.
  5. kImageMin: Denotes the first stimulus. Every stimulus has a code number but the code number for the first stimulus is always 4096. 4097 denotes the second stimulus, 4098 denotes the third stimulus etc.
  6. kResponse_leftbutton: Left mouse button presses are registered as 128.
  7. kResponse_rightbutton: Left mouse button presses are registered as 129.
  8. Fs: Sampling frequency. The data is recorded at 2000 Hz.
  9. startTime: Start time of the recording.
  10. sampleTime: Time between each sample point (1/Fs) in milliseconds.
  11. trialTimeCourse: Time course of trial. e.g. -1:1/S.Fs:4 (A 5 second trial that consists of 8000 sample points).

Information about data files (i.e which experiment session is recorded under which data file) and electrode montage can be found in the physiology file of each subject. e.g. /Volumes/data/UT/YAO/YAOPhysiology.docx

The next step is to load the to load the appropriate data files and adjust the epochs based on the trial onset times.