diff --git a/ClusterPrefab.cs b/ClusterPrefab.cs
index ad98aac..2fc6867 100644
--- a/ClusterPrefab.cs
+++ b/ClusterPrefab.cs
@@ -63,7 +63,9 @@ public class ClusterPrefab : ScriptableObject {
 
     public void GarbageCollection() {
         HashSet<Nucleus> visitedNuclei = new();
-        MarkNuclei(visitedNuclei, this.output);
+        foreach (Nucleus output in this.outputs)
+            MarkNuclei(visitedNuclei, output);
+        //MarkNuclei(visitedNuclei, this.output);
         //Debug.Log($"Garbage collection found {visitedNuclei.Count} Nuclei");
         this.nuclei.RemoveAll(nucleus => nucleus is Nucleus n && visitedNuclei.Contains(n) == false);
     }
diff --git a/Editor/ClusterInspector.cs b/Editor/ClusterInspector.cs
index d4712bc..4018cc9 100644
--- a/Editor/ClusterInspector.cs
+++ b/Editor/ClusterInspector.cs
@@ -130,7 +130,7 @@ public class ClusterInspector : Editor {
 
         void OnAddClusterOutput() {
             Nucleus newOutput = new Neuron(this.prefab, "New Output");
-
+            this.prefab.RefreshOutputs();
             outputsField.choices = this.prefab.outputs.Select(output => output.name).ToList();
             outputsField.value = newOutput.name;
 
diff --git a/NucleusArray.cs b/NucleusArray.cs
index 368aac3..89ae516 100644
--- a/NucleusArray.cs
+++ b/NucleusArray.cs
@@ -1,6 +1,8 @@
 using System.Linq;
 using System.Collections.Generic;
 using UnityEngine;
+using Unity.Mathematics;
+using static Unity.Mathematics.math;
 
 [System.Serializable]
 public class NucleusArray {
@@ -63,25 +65,57 @@ public class NucleusArray {
     public Dictionary<int, Nucleus> thingReceivers = new();
 
 
-    public virtual void ProcessStimulus(int thingId, Vector3 inputValue, string thingName = null) {
-        CleanupReceivers();
-        if (!thingReceivers.TryGetValue(thingId, out Nucleus selectedReceiver)) {
-            // Debug.Log($"No receiver found for {thingId}");
-            foreach (Nucleus receptor in this.nuclei) {
-                if (receptor is not Nucleus receiver)
-                    continue;
-
-                if (thingReceivers.ContainsValue(receiver) == false) {
-                    // receiver is not used yet
-                    // Debug.Log($"{thingId} -> {receiver.name}");
-                    thingReceivers.Add(thingId, receiver);
+    private Nucleus FindReceiver(int thingId, float3 inputValue) {
+        // No existing nucleus for this thing
+        float inputMagnitude = length(inputValue);
+        Nucleus selectedReceiver = null;
+        float selectedMagnitude = 0;
+        foreach (Nucleus receiver in this.nuclei) {
+            if (thingReceivers.ContainsValue(receiver) == false) {
+                // We found an unusued receiver
+                thingReceivers.Add(thingId, receiver);
+                return receiver;
+            }
+            else if (receiver.isSleeping) {
+                // A sleeping receiver is not active and can therefore always be used
+                thingReceivers.Add(thingId, receiver);
+                return receiver;
+            }
+            else if (selectedReceiver == null) {
+                // If we haven't found a receiver yet, just start by taking the first
+                selectedReceiver = receiver;
+                selectedMagnitude = length(selectedReceiver.outputValue);
+            }
+            // Look for the receiver with the lowest magnitude
+            else {
+                float magnitude = length(receiver.outputValue);
+                
+                if (magnitude < inputMagnitude && length(receiver.outputValue) < selectedMagnitude) {
                     selectedReceiver = receiver;
-                    break;
+                    selectedMagnitude = length(selectedReceiver.outputValue);
                 }
             }
         }
+        if (selectedReceiver != null) {
+            // Replace the receiver
+            // Find the thingId current associated with the receiver
+            int keyToRemove = thingReceivers.FirstOrDefault(r => r.Value.Equals(selectedReceiver)).Key;
+            if (keyToRemove != 0 || thingReceivers.ContainsKey(keyToRemove))
+                thingReceivers.Remove(keyToRemove);
+            // And add the new association
+            thingReceivers.Add(thingId, selectedReceiver);
+        }
+        return selectedReceiver;
+    }
+
+    public virtual void ProcessStimulus(int thingId, Vector3 inputValue, string thingName = null) {
+        CleanupReceivers();
+        if (!thingReceivers.TryGetValue(thingId, out Nucleus selectedReceiver)) {
+            // No existing nucleus for this thing
+            selectedReceiver = FindReceiver(thingId, inputValue);
+        }
         if (selectedReceiver == null)
-            return; 
+            return;
 
         if (thingName != null) {
             string baseName = selectedReceiver.name;
@@ -100,10 +134,8 @@ public class NucleusArray {
         // Remove a thing-receiver connection when the nucleus is inactive
         List<int> receiversToRemove = new();
         foreach (KeyValuePair<int, Nucleus> item in thingReceivers) {
-            if (item.Value.isSleeping) {
-                //Nucleus n = item.Value as Nucleus;
-                receiversToRemove.Add(item.Key);
-            }
+            if (item.Value.isSleeping)
+                receiversToRemove.Add(item.Key);            
         }
         foreach (int thingId in receiversToRemove) {
             Nucleus selectedReceiver = thingReceivers[thingId];