diff --git a/Cluster.cs b/Cluster.cs
index 255dc66..7c77590 100644
--- a/Cluster.cs
+++ b/Cluster.cs
@@ -193,8 +193,22 @@ public class Cluster : INucleus {
         
         // This does not work because the prefab nucleus does not have a state
         this.prefab.inputs[0].UpdateState(sum);
+        //this._outputValue = this.output.outputValue;
+        UpdateResult(this.output.outputValue);
     }
 
+    public virtual void UpdateResult(Vector3 result) {
+        // float d = Vector3.Distance(result, this.outputValue);
+        // if (d < 0.5f) {
+        //     //Debug.Log($"insignificant update: {d}");
+        //     return;
+        // }
+
+        this.outputValue = result;
+        foreach (INucleus receiver in this.receivers)
+            receiver.UpdateState();
+    }
+    
     public void UpdateNuclei() {
         this.stale++;
         if (this.stale >  2)
diff --git a/ClusterPrefab.cs b/ClusterPrefab.cs
index 151cba5..5786820 100644
--- a/ClusterPrefab.cs
+++ b/ClusterPrefab.cs
@@ -25,8 +25,11 @@ public class ClusterPrefab : ScriptableObject {
             if (this._inputs == null) {
                 this._inputs = new();
                 foreach (IReceptor receptor in this.nuclei) {
-                    if (receptor is INucleus nucleus)
-                        this._inputs.Add(nucleus);
+                    if (receptor is INucleus nucleus) {
+                        // inputs have no incoming synapses yet.
+                        if (nucleus.synapses.Count == 0)
+                            this._inputs.Add(nucleus);
+                    }
                 }
             }
             return this._inputs;