{
  "onset": {
    "Description": "Position of event marker in seconds relative to the start.",
    "Units": "s"
  },
  "duration": {
    "Description": "Duration of the event in seconds.",
    "Units": "s"
  },
  "event_type": {
    "LongName": "Event category",
    "Description": "The main category of the event.",
    "Levels": {
      "show_face": "Display a face to mark end of pre-stimulus and start of blink-inhibition.",
      "show_face_initial": "Display a face at the beginning of the recording.",
      "show_circle": "Display a white circle to mark end of the stimulus and blink inhibition.",
      "show_cross": "Display only a white cross to mark start of trial and fixation.",
      "left_press": "Experiment participant presses a key with left index finger.",
      "right_press": "Experiment participant presses a key with right index finger.",
      "setup_left_sym": "Setup for experiment with pressing key with left index finger means a face with above average symmetry.",
      "setup_right_sym": "Setup for experiment with pressing key with right index finger means a face with above average symmetry.",
      "double_press": "Experiment participant presses both keys ."
    },
    "HED": {
      "show_face": "Sensory-event, Experimental-stimulus, (Def/Face-image, Onset), (Def/Blink-inhibition-task,Onset),(Def/Cross-only, Offset)",
      "show_face_initial": "Sensory-event, Experimental-stimulus, (Def/Face-image, Onset), (Def/Blink-inhibition-task,Onset), (Def/Fixation-task, Onset)",
      "show_circle": "Sensory-event, (Intended-effect, Cue), (Def/Circle-only, Onset), (Def/Face-image, Offset), (Def/Blink-inhibition-task, Offset), (Def/Fixation-task, Offset)",
      "show_cross": "Sensory-event, (Intended-effect, Cue), (Def/Cross-only, Onset), (Def/Fixation-task, Onset),  (Def/Circle-only, Offset)",
      "left_press": "Agent-action, Participant-response, Def/Press-left-finger",
      "right_press": "Agent-action, Participant-response, Def/Press-right-finger",
      "setup_left_sym": "Experiment-structure, (Def/Left-sym-cond, Onset), (Def/Initialize-recording, Onset)",
      "setup_right_sym": "Experiment-structure, (Def/Right-sym-cond, Onset), (Def/Initialize-recording, Onset)",
      "double_press": "Agent-action, Indeterminate-action, (Press, Keyboard-key)"
    }
  },
  "face_type": {
    "Description": "Factor indicating type of face image being displayed.",
    "Levels": {
      "famous_face": "A face that should be recognized by the participants.",
      "unfamiliar_face": "A face that should not be recognized by the participants.",
      "scrambled_face": "A scrambled face image generated by taking face 2D FFT."
    },
    "HED": {
      "famous_face": "Def/Famous-face-cond",
      "unfamiliar_face": "Def/Unfamiliar-face-cond",
      "scrambled_face": "Def/Scrambled-face-cond"
    }
  },
  "rep_status": {
    "Description": "Factor indicating whether this image has been already seen.",
    "Levels": {
      "first_show": "Factor level indicating the first display of this face.",
      "immediate_repeat": "Factor level indicating this face was the same as previous one.",
      "delayed_repeat": "Factor level indicating face was seen 5 to 15 trials ago."
    },
    "HED": {
      "first_show": "Def/First-show-cond",
      "immediate_repeat": "Def/Immediate-repeat-cond",
      "delayed_repeat": "Def/Delayed-repeat-cond"
    }
  },
  "trial": {
    "Description": "Indicates which trial this event belongs to.",
    "HED": "Experimental-trial/#"
  },
  "rep_lag": {
    "Description": "How face images before this one was the image was previously presented.",
    "HED": "(Face, Item-interval/#)"
  },
  "stim_file": {
    "Description": "Path of the stimulus file in the stimuli directory.",
    "HED": "(Image, Pathname/#)"
  },
  "hed_def_sensory": {
    "Description": "Metadata dictionary for gathering sensory definitions",
    "HED": {
      "cross_only_def": "(Definition/Cross-only, (Visual-presentation, (Foreground-view, (White, Cross), (Center-of, Computer-screen)), (Background-view, Black), Description/A white fixation cross on a black background in the center of the screen.))",
      "face_image_def": "(Definition/Face-image, (Visual-presentation, (Foreground-view, ((Image, Face, Hair), Color/Grayscale), ((White, Cross), (Center-of, Computer-screen))), (Background-view, Black), Description/A happy or neutral face in frontal or three-quarters frontal pose with long hair cropped presented as an achromatic foreground image on a black background with a white fixation cross superposed.))",
      "circle_only_def": "(Definition/Circle-only, (Visual-presentation, (Foreground-view, ((White, Circle), (Center-of, Computer-screen))), (Background-view, Black), Description/A white circle on a black background in the center of the screen.))"
    }
  },
  "hed_def_actions": {
    "Description": "Metadata dictionary for gathering participant action definitions",
    "HED": {
      "press_left_finger_def": "(Definition/Press-left-finger, ((Index-finger, (Left-side-of, Experiment-participant)), (Press, Keyboard-key), Description/The participant presses a key with the left index finger to indicate a face symmetry judgment.))",
      "press_right_finger_def": "(Definition/Press-right-finger, ((Index-finger, (Right-side-of, Experiment-participant)), (Press, Keyboard-key), Description/The participant presses a key with the right index finger to indicate a face symmetry evaluation.))"
    }
  },
  "hed_def_conds": {
    "Description": "Metadata dictionary for gathering experimental condition definitions",
    "HED": {
      "famous_face_cond_def": "(Definition/Famous-face-cond, (Condition-variable/Face-type, (Image, (Face, Famous)), Description/A face that should be recognized by the participants))",
      "unfamiliar_face_cond_def": "(Definition/Unfamiliar-face-cond, (Condition-variable/Face-type, (Image, (Face, Unfamiliar)), Description/A face that should not be recognized by the participants.))",
      "scrambled_face_cond_def": "(Definition/Scrambled-face-cond, (Condition-variable/Face-type, (Image, (Face, Disordered)), Description/A scrambled face image generated by taking face 2D FFT.))",
      "first_show_cond_def": "(Definition/First-show-cond, ((Condition-variable/Repetition-type, (Item-count/1, Face), Item-interval/0), Description/Factor level indicating the first display of this face.))",
      "immediate_repeat_cond_def": "(Definition/Immediate-repeat-cond, ((Condition-variable/Repetition-type, (Item-count/2, Face), Item-interval/1), Description/Factor level indicating this face was the same as previous one.))",
      "delayed_repeat_cond_def": "(Definition/Delayed-repeat-cond, (Condition-variable/Repetition-type, (Item-count/2, Face), (Item-interval, (Greater-than-or-equal-to, Item-interval/5)), Description/Factor level indicating face was seen 5 to 15 trials ago.))",
      "left_sym_cond_def": "(Definition/Left-sym-cond, (Condition-variable/Key-assignment, ((Index-finger, (Left-side-of, Experiment-participant)), (Behavioral-evidence, Symmetrical)), ((Index-finger, (Right-side-of, Experiment-participant)), (Behavioral-evidence, Asymmetrical)), Description/Left index finger key press indicates a face with above average symmetry.))",
      "right_sym_cond_def": "(Definition/Right-sym-cond, (Condition-variable/Key-assignment, ((Index-finger, (Right-side-of, Experiment-participant)), (Behavioral-evidence, Symmetrical)), ((Index-finger, (Left-side-of, Experiment-participant)), (Behavioral-evidence, Asymmetrical)), Description/Right index finger key press indicates a face with above average symmetry.))"
    }
  },
  "hed_def_tasks": {
    "Description": "Metadata dictionary for gathering task definitions",
    "HED": {
      "face_symmetry_evaluation_task_def": "(Definition/Face-symmetry-evaluation-task, (Task, Experiment-participant, (See, Face), (Discriminate, (Face, Symmetrical)), (Press, Keyboard-key), Description/Evaluate degree of image symmetry and respond with key press evaluation.))",
      "blink_inhibition_task_def": "(Definition/Blink-inhibition-task, (Task, Experiment-participant, Inhibit-blinks, Description/Do not blink while the face image is displayed.))",
      "fixation_task_def": "(Definition/Fixation-task, (Task, Experiment-participant, (Fixate, Cross), Description/Fixate on the cross at the screen center.))"
    }
  },
  "hed_def_setup": {
     "Description": "Metadata dictionary for gathering setup definitions",
     "HED": {
        "setup_def": "(Definition/Initialize-recording, (Recording))"
      }

  },
  "value": {
    "Description": "Numerical event marker",
    "Levels": {
      "x0": "Disappearance of face image and display of the inter-stimulus circle simultaneously",
      "x1": "Disappearance of face image and display of the inter-stimulus circle simultaneously",
      "x2": "Initial setup with left finger key press indicating above average symmetry",
      "x3": "Initial setup with right finger key press indicating above average symmetry",
      "x5": "Initial presentation of famous face",
      "x6": "Immediate repeated  presentation of famous face",
      "x7": "Delayed repeated  presentation of famous face",
      "x13": "Initial presentation of unfamiliar face",
      "x14": "Immediate repeated  presentation of unfamiliar face",
      "x15": "Delayed repeated  presentation of unfamiliar face",
      "x17": "Initial presentation of scrambled face",
      "x18": "Immediate repeated  presentation of scrambled face",
      "x19": "Delayed repeated  presentation of scrambled face",
      "x256": "Left finger key press",
      "x4096": "Right finger key press",
	  "x4352": "Left and right finger key presses"
    }
  }
}