From 9568cdfcfbbb6a6cd30e562507b6c188d09537ae Mon Sep 17 00:00:00 2001
From: Pascal Serrarens <pascal@passer.life>
Date: Fri, 3 Jul 2026 09:31:28 +0200
Subject: [PATCH] Backpropagation in synapse

---
 Runtime/Scripts/Core/Synapse.cs | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Runtime/Scripts/Core/Synapse.cs b/Runtime/Scripts/Core/Synapse.cs
index a0bf74d..5cca04a 100644
--- a/Runtime/Scripts/Core/Synapse.cs
+++ b/Runtime/Scripts/Core/Synapse.cs
@@ -1,5 +1,6 @@
 using System;
 using UnityEngine;
+using Unity.Mathematics;
 
 namespace NanoBrain {
 
@@ -31,6 +32,20 @@ namespace NanoBrain {
             this.weight = weight;
         }
 
+        public virtual void BasicBackPropagation(float error, float learningRate) {
+            float derivative = error;
+            switch (neuron.activator) {
+                case Neuron.ActivationType.Linear:
+                    derivative *= 1;
+                    break;
+                default:
+                    break;
+            }
+            derivative *= math.length(neuron.activation);
+
+            float deltaWeight = learningRate * derivative;
+            this.weight += deltaWeight;
+        }
     }
 
 }
\ No newline at end of file