diff --git a/7t_trt/participants.json b/7t_trt/participants.json
new file mode 100644
index 000000000..693d4584e
--- /dev/null
+++ b/7t_trt/participants.json
@@ -0,0 +1,21 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age_at_first_scan_years": {
+    "LongName": "age_at_first_scan_years",
+    "Units": "years"
+  }
+}
\ No newline at end of file
diff --git a/ds000117/participants.json b/ds000117/participants.json
new file mode 100644
index 000000000..cdc384855
--- /dev/null
+++ b/ds000117/participants.json
@@ -0,0 +1,34 @@
+{
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  },
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "first_ses": {
+    "LongName": "first session",
+    "Description": "Indicates which session was the first session for this subject.",
+    "Levels": {
+      "meg": {
+        "Description": "meg was the first session"
+      },
+      "mri": {
+        "Description": "mri was the first session"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/ds008/participants.json b/ds008/participants.json
new file mode 100644
index 000000000..f197b48f4
--- /dev/null
+++ b/ds008/participants.json
@@ -0,0 +1,22 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  }
+}
\ No newline at end of file
diff --git a/ds009/participants.json b/ds009/participants.json
new file mode 100644
index 000000000..d5120b33c
--- /dev/null
+++ b/ds009/participants.json
@@ -0,0 +1,21 @@
+{
+  "Age": {
+    "LongName": "Age",
+    "Units": "years",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  },
+  "Gender": {
+    "LongName": "Gender",
+    "TermURL": "https://schema.org/gender",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "https://schema.org/Female"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "https://schema.org/Male"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/ds101/participants.json b/ds101/participants.json
new file mode 100644
index 000000000..f197b48f4
--- /dev/null
+++ b/ds101/participants.json
@@ -0,0 +1,22 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  }
+}
\ No newline at end of file
diff --git a/ds102/participants.json b/ds102/participants.json
new file mode 100644
index 000000000..919de8b14
--- /dev/null
+++ b/ds102/participants.json
@@ -0,0 +1,25 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "D": {
+        "Description": "D"
+      },
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  }
+}
diff --git a/ds108/participants.json b/ds108/participants.json
new file mode 100644
index 000000000..f197b48f4
--- /dev/null
+++ b/ds108/participants.json
@@ -0,0 +1,22 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  }
+}
\ No newline at end of file
diff --git a/ds110/participants.json b/ds110/participants.json
new file mode 100644
index 000000000..f197b48f4
--- /dev/null
+++ b/ds110/participants.json
@@ -0,0 +1,22 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  }
+}
\ No newline at end of file
diff --git a/ds114/participants.json b/ds114/participants.json
new file mode 100644
index 000000000..f6c22a1bc
--- /dev/null
+++ b/ds114/participants.json
@@ -0,0 +1,15 @@
+{
+  "dominant_hand": {
+    "LongName": "dominant_hand",
+    "Levels": {
+      "left": {
+        "Description": "left",
+        "TermURL": "http://purl.bioontology.org/ontology/SNOMEDCT/87683000"
+      },
+      "right": {
+        "Description": "right",
+        "TermURL": "http://purl.bioontology.org/ontology/SNOMEDCT/46669005"
+      }
+    }
+  }
+}
diff --git a/ds116/participants.json b/ds116/participants.json
new file mode 100644
index 000000000..d17e209aa
--- /dev/null
+++ b/ds116/participants.json
@@ -0,0 +1,65 @@
+{
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  },
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  },
+  "handedness": {
+    "LongName": "handedness",
+    "Description": "String value indicating handedness",
+    "TermURL": "http://purl.bioontology.org/ontology/SNOMEDCT/57427004",
+    "Levels": {
+      "L": {
+        "Description": "Left",
+        "TermURL": "http://purl.bioontology.org/ontology/SNOMEDCT/87683000"
+      },
+      "R": {
+        "Description": "Right",
+        "TermURL": "http://purl.bioontology.org/ontology/SNOMEDCT/46669005"
+      }
+    }
+  },
+  "ethnicity": {
+    "LongName": "ethnicity",
+    "TermURL": "http://purl.obolibrary.org/obo/HANCESTRO_0004",
+    "Levels": {
+      "Asian": {
+        "Description": "Asian",
+        "TermURL": "http://purl.obolibrary.org/obo/HANCESTRO_0008"
+      },
+      "Asian/Caucasian": {
+        "Description": "Asian Caucasian"
+      },
+      "Caucasian": {
+        "Description": "Caucasian",
+        "TermURL": "http://purl.obolibrary.org/obo/HANCESTRO_0005"
+      },
+      "Caucasian/African/NativeSouthAmerican": {
+        "Description": "Caucasian African NativeSouthAmerican"
+      },
+      "Hispanic": {
+        "Description": "Hispanic",
+        "TermURL": "http://purl.obolibrary.org/obo/HANCESTRO_0014"
+      },
+      "MiddleEastern": {
+        "Description": "MiddleEastern",
+        "TermURL": "http://purl.obolibrary.org/obo/HANCESTRO_0015"
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/eeg_ds000117/participants.json b/eeg_ds000117/participants.json
new file mode 100644
index 000000000..6123ff9ab
--- /dev/null
+++ b/eeg_ds000117/participants.json
@@ -0,0 +1,22 @@
+{
+  "age": {
+    "LongName": "age",
+    "Units": "year",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0000011"
+  },
+  "sex": {
+    "LongName": "sex",
+    "Description": "String value indicating phenotypical sex.",
+    "TermURL": "http://purl.obolibrary.org/obo/PATO_0001894",
+    "Levels": {
+      "F": {
+        "Description": "Female",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000383"
+      },
+      "M": {
+        "Description": "Male",
+        "TermURL": "http://purl.obolibrary.org/obo/PATO_0000384"
+      }
+    }
+  }
+}
\ No newline at end of file